The basics of building good garden soil

My simple worm bin

Although it seems like desert soils would not be suitable for vegetable gardening, the reality is all they lack is water to be productive. However, to make these soils more water efficient, and to replenish nutrients used in growing plants, amendments are necessary for all types of desert soils. I will only be discussing organic methods in this section.

Sandy soils are the most challenging and ‘needy’ when it comes to amendments.  The addition of organic matter is necessary to help these soils maintain a moisture level conducive to growing healthy plants. 

Clay soils hold moisture far better than sandy soils, but if the clay is very heavy it can hold too much water and can cause root rot and other problems. The addition of organic matter in this case is to provide better drainage and aeration of the soil, both essential to healthy plant growth.

The best types of amendments come from animal sources. Although chicken manure, bat guano, fish emulsions provide nitrogen to feed plants, they do not contain other essential nutrients (such as potassium, potash, calcium and carbon to name a few) which is depleted from the soil after every growing season. The goal is not just to feed the garden soil, but to create a soil structure which supports healthy plants, reduces the amount of water needed, increases beneficial soil microbes, attracts beneficial insects and soil building organisms such as earthworms. The best way to tell if your garden soil is being tended to properly is the appearance of earthworms. You can’t just add them to your garden and hope they will multiply. In most areas of the country, “if you build it, they will come.” However, I’ve been informed by the University of Arizona this is rarely the case in the desert as earthworms are not endemic here. So what’s a gardener to do? Make an earthworm bin and use their castings. It’s much easier to maintain a stable environment in a bin than it is in your garden.

Adding animal manures such as from steer or horses also provides organic matter that helps sandy soil hold moisture and improves drainage in clay soil, providing low levels of nitrogen to feed the plants. Never add clay soil to sandy soil. This makes cement, which is certainly not the goal here! Also important is adding straw. Although straw does require nitrogen to break down, adding it along with the manure several months before planting will start the decomposition process and also allow the manure to ‘age’ before planting. This is important as some manures contain high levels of salt (from feed) that needs to be leached out prior to planting to avoid burning new plants. I purchase both steam sterilized steer manure and straw way ahead of my needs, and allow it sit for at least 6 months or longer before using. Horse manure can contain weed seeds and sometimes Bermuda grass (which you definitely don’t want in your garden), so be careful of using unless you have the time to sterilize it yourself, by placing heavy weight clear plastic over a pile and letting it cook in the hot summer sun for a few months. This will kill off most seeds.

Of course, don’t forget compost. If you aren’t composting and you want a garden, you need to start. Compost bins can make life easier, but are not necessary. I’ve always composted directly in my garden, as turning piles and keeping them moist is just too much work. I bury kitchen scraps (vegetable and fruit trimmings, egg shells (in moderation), and other plant matter (no meat, dairy or fish) in between rows. That’s it! Nature will take its course.

Diagnosing mysterious plant problems

Velvet mesquite, one of our best native trees

Nothing is more frustrating than putting a lot of hard work and spending tons of time caring for landscape plants, only to have them succumb to some kind of disease or pest. If your plant is looking a little sickly, here are some common symptoms to look for to help you diagnose the problem, along with fairly simple solutions.

Is your plant wilting? Obviously, the first thing that comes to mind is lack of water. If you have ruled out your plant being thirsty, there are a number of other problems that can cause wilting. The reality is over watering can also make leaves wilt, because the roots are rotting. Make sure your plant is not getting too much water. The soil needs to dry out in between waterings so the roots can obtain oxygen. Yes! Roots need to be able to breathe.

Texas Root Rot is prevalent in the southwest, and causes significant root loss in short order. By the time you see wilting, it is dead. Plant resistant species, but never in the same spot. Which plants succumb to Texas Root Rot? Here’s a sampling:

Ash

Elm

African Sumac

California Pepper

Roses

Xylosma

Silk Oak

Bottle Tree

Roses

All stone fruit trees (peaches, plums and apricots)

All nut trees

Notice not one of those is a desert native. This is one of the many reasons why I recommend planting natives.

Some insects can cause wilting as they water out of the leaves. Look on underneath leaves for sucking insects like aphids and mites. If you see them, spray off with the garden hose. No chemicals needed.

What about leaf color changes that aren’t normal for the species? Are the leaves turning yellow? In some cases, this could be nitrogen deficiency. Planting natives usually means fertilizer is rarely warranted since they are adapted to the soil. If the plant is not a desert native, and the leaves are yellow with green veins, this is a sign of iron chlorosis, caused by a deficiency of iron in the soil, or by high pH soils. Soils with high alkalinity prevent the absorption of iron. Treating is expensive and labor intensive. It is better to choose plants that grow in alkaline soils.

Also keep in mind, that early leaf coloration is often caused by drought. Stick with desert natives with low water use requirements.

Is your plant just sitting there and not growing? One of the deadliest thing that can happen to your new tree is planting too deep. If the planting hole was deeper than the root ball, chances are it sunk into the hole and dirt has gathered around the trunk. You can try removing soil that is up against the trunk base. This might work, and worth a try. Next time remember to never dig a hole deeper than the root ball.

Many times plant problems arise because the species is not suitable for our desert climate and soils. Choosing desert native plants is a smart way to avoid many problems and have greater success with minimal effort.

Those pesky and destructive whiteflies: what's a gardener to do?

If you see a cloud of white insects flying around your vegetable garden, unfortunately this means you have the dreaded whitefly. They are especially attracted to lettuce, and are a huge problem for Arizona lettuce growers in the winter. They also attack tomatoes, peppers, cabbage and the foliage of carrots, and have a liking to herbs like parsley as well. They are a sucking insect, and can kill the plant within a short amount of time. Since they love dry, dusty conditions, the desert is a perfect climate.

They are dreaded because they multiple incredibly fast and are very difficult to control naturally. Although some experts recommend using beneficial insects for a natural control, this method is not particularly successful in the desert environment because conditions are just not that favorable for many beneficial insects to stick around and do any good. You can try sticky traps, which need replacing as they fill up with insects. Barriers such as floating row covers work, provided you get them on before the whitefly sets eggs on your plants, but this does not work once temperatures rise into the mid to upper 80’s because it just plain gets too hot under there.

Since whiteflies love dry, dusty conditions, your best bet is to hose off plants often. If you have one plant they particularly like, it may be worth it to sacrifice that one plant to reduce infestation of the others.

Common problems with cactus and succulents

Damaged by the Agave Snout-nose weevil

Cactus and succulents are relatively problem free, as long as growing conditions, soil, drainage and sun orientation are correct for the species. Always make sure you are purchasing plants are suitable for both the heat and cold. Not all of these plants can handle the brutal low elevation summer heat, or temperatures dipping into the teens. When in doubt: Plant natives!

Cochineal scale is relatively common on prickly pear and cholla. It is evidenced by cottony-like spots on the pads and stems. This insect sucks out nutrients. If left without treatment, it will eventually kill the plant. Control is simple by using repeated hard sprays of water. It’s important to catch this early, however. If the entire plant is covered with the white substance, it’s unlikely you’ll ever be able to get rid of it. It’s been to remove and replace the plant. As a side note, the female of the insect that causes the white cottony mass is the source of a red dye known as cochineal red. The red dye is used in clothing and candy, so if you are vegetarian, think twice about eating candy dyed red!

The cactus longhorn beetle attacks some columnar cactus and prickly pears leaving chewed areas on the uppermost parts. It is identified by very long antennae, as long as the beetle itself. Hand picking is considered the best control method, so you’ll need to be vigilant. The larvae will eat the inside of the plant, so they are hard to detect and control before the plant is dead.

Sahuaro rot (bacterial necrosis), is an infection caused by a number of things. It can result from sunburn, injury (including transport to planting site), frost damage, too much water and poor drainage. Bacteria spreads inside the plant before you notice what is happening. When a black, odorous liquid oozes out of the plants epidermis, it is too late to save. If this appears on an arm, removal of the arm may save it, but it must be caught before the rotting spreads into the main stem.

And what about those holes in sahuaros made by birds? Birds and sahuaros have lived harmoniously together for centuries, so trust me, the sahuaro will be fine. Those holes, usually made by woodpeckers, will later become homes for other critters, including bats and the tiny pygmy owl.

Some agave species are attacked by the agave snout-nose weevil. You’ll know you’ve got them if the leaves of the agave are laying flat on the ground. This insect prefers stressed plants (think thirsty, overwatered, too much sun, too little sun, poor drainage, temperatures too hot or too cold) and seems to prefer the Century Plant, one of the largest of the agave species. Infestation is hard to detect, and by the time the plant wilts it is too late. Remove, dig up the weevil, and kill it before replanting.

The scoop on fertilizers: Is organic better than chemical versions?

If you don't have a worm bin, you'll want one!

You might tend to think that organic fertilizers are better for your plants. However, the fact is plants can't tell the difference between organic and synthetic (chemical) fertilizers. They are both used by the plant in the same way. There are basically 3 components in fertilizers. Macronutrients are Nitrogen (N), Phosphorus (P) and Potassium (K). All 3 are usually found in commercial fertilizer in varying proportions. With organic fertilizers you typically need 3 different materials to add all 3 macronutrients. In the Tucson and surrounding communities, soils high in alkalinity (pH) can be a problem, as it binds nutrients from becoming available to the plant. This makes it even harder to deliver necessary nutrients to your plants.

Aside from the 3 macronutrients, plants also need micronutrients, which are much more difficult to find in chemical fertilizers. Micronutrient deficiencies in the soil are one of the reasons food grown today is not as nutritious as it used to be. This is where the use of organic fertilizers shine. They provide much more than the basic 3 nutrients. Organic fertilizers also improve soil structure and lower pH, which increases the availability of all nutrients.

Because each type of organic matter offers different nutritional support, you will need to add as many different kinds as you can.

Types of organic fertilizers include:

Nitrogen boosters: animal manures, plant matter (such as leaves), compost, fish meal, bat guano, worm castings and blood meal.

Phosphorus boosters: bone meal, rock phosphate

Potassium boosters: kelp meal, greensand, wood ash (depending on wood type)

Micronutrient suppliers: compost (which also contains beneficial microorganisms), gypsum (which helps break up hard alkaline soils), kelp meal and worm castings.

A new addition to the world of organic soil additives are Humates. They are touted to improve alkaline soils, but are pricey.

Sulfur can be added to soil to also correct high alkalinity, but the jury is out as to how effective this is.

While plants don't know the difference between chemical and organic fertilizers, it is important to understand that organic fertilizers last longer in the soil, and, especially when using manures and compost, create a good soil structure that retains water and encourages healthy soil organisms such as earthworms. Chemical fertilizers do not amend the soil. Period.

Never heard of Biochar? Time's a-wasting!

Biochar boosts your compost

If you have not yet heard of Biochar, you will in the near future. Biochar is a soil amendment with the properties unlike any other. Used in agriculture for over 3000 years, Biochar is a component of the incredibly fertile soils of the Amazon. These soils, called terra-preta, is why the Amazon jungle is unlike anyplace else on earth.

So what can Biochar do for your garden? Biochar improves nutrient retention of soil, decreasing the need for additional amendments. Its ability to hold carbon in the soil has been proven in research. While Biochar won’t make poor soil perfect, it will enhance the effectiveness and longevity of compost.

Biochar is now commercially available, but if you are a do-it-yourselfer, you can make Biochar at home. Online resources cover many ways to create your own Biochar, but if you decide to buy instead, keep in mind that although it’s expensive, it lasts a very long time in your garden. Here's one article that teaches you how to make your own. Making Biochar to Improve Soil (Mother Earth News).

When's the best time to set out landscape plants?

Blue Palo Verde, our State Tree, is best fall-planted

Fall is planting time in the desert, and if you are new to the Tucson and Green Valley areas, you may be wondering just exactly when fall arrives.

That’s a tricky one, because fall for many parts of the country is September. However, here, September is very hot, often returning to triple digit temperatures after the summer rains depart.

Ideal planting time, therefore, is October to early November. But not for all plants. Desert natives are planted during that time, but other plants, including cactus and succulents and most non-natives, should be planted in the spring.

Anything that goes dormant during the winter months, such as Lantana, Bougainvillea, Queen’s Wreath, should NOT be planted in the fall. These plants often do not survive the winter when planted at this time, since a hard freeze occurring before their roots are established can lead to plant death. Ironically, nurseries will put these plants on sale in late summer, leading you to believe it’s time to plant. Don’t be fooled!

Lantana should be planted in the spring, preferably after the last frost, which for Tucson is about April 1^st, and in Green Valley about April 7^th. There are two varieties of Lantana, although many colors available. The bush lantana grows quite large, up to 4 feet or more, whereas trailing lantana stays short, about 18 inches, spreading to about 3 feet.

Cactus should be planted in the spring, usually once the nights have warmed up. This means May or early June. Avoid planting cactus and succulents in the fall, since you might lose them to root rot. Also make sure you are buying a species hardy for this area. Not all cactus species grow here, and many times nurseries sell plants meant to keep indoors.

Velvet mesquite is a native tree perfect for providing filtered shade. This is a large tree, and needs lots of room to grow, sometimes up to 40 feet. They prefer fall planting, and will establish quicker if watered daily for the first week, then back off to every other day for the next week, every two days for the week after that, until you are irrigating once a week. Back off to twice a month through December and January.

Succulents (such as agaves) should be planted in the spring, usually once the nights have warmed up. This means May or early June. Avoid planting succulents in the fall, since you might lose them to root rot. Also make sure you are buying a species hardy for this area. Like cactus, not all succulent species grow here, and often nurseries sell plants meant to keep indoors.

Another great native tree to plant in the fall is the kidneywood. This is a slow growing, small tree, perfect for patios and small spaces. The kidneywood has white flowers in the summer that smell like vanilla. This may be a difficult plant to find, especially at a regular nursery. Try Desert Survivor’s in Tucson, since they are most likely to have this tree in stock.

Growing cactus in pots

Golden Barrel cactus make great container plants.

There are many cactus species that lend themselves to container gardens, just make sure you pick the right species, and the correct pot.

Many times you will see cactus gardens in the grocery store, falsely leading you to believe these will live a long time indoors. The reality is it is very hard to keep indoor cactus alive unless you are willing to move them around your house so they can receive the proper amount of sunlight. That can be pretty hard to determine if the plants come with no plant identification. Not all cactus like full sun.

The other problem is many of those pre-made cactus gardens do not have a drainage hole in the bottom of the container. That is a huge problem, since all cactus love good drainage. It is very easy to over water containers with no holes, leading to root rot.

If you are looking for outdoor cactus plantings, just make sure you are giving the cactus the right amount of light for the species, and make sure you give it plenty of water if the pot is in full sun. If that sounds contradictory to what you think about cactus, just remember that cactus in the ground need far less water than cactus in pots. Once in a container in full sun, cactus will need weekly watering during the hot summer months.

The best containers should breathe well (no plastic) and have sufficient depth and width for plants to spread their roots. You’ll want a container at least 12” deep and the wider the better. Saucer shaped pots are perfect. Just make sure you know the mature size of your plant, and adjust the size accordingly. Trust me: transplanting them is not fun if you start out with a container that is way too small. And how do you get those prickly things into pots anyway? Easy! Wear leather gloves, and wrap the plant in thick layers of newspaper so the spines can’t poke you in process.

The challenges of desert soils

Our native desert willow is adapted to alkaline soil.

Whether you are a gardener or just love plants, you probably have heard the soils in most of Arizona are highly alkaline (High in pH.) So what does that mean to your garden and your choice of landscape plants? Plenty.

The most significant affect pH (which stands for potential hydrogen) has on plant growth is the availability of important plant nutrients. It’s not that these nutrients aren’t there, although is some instances that may be the case, but it’s that the pH affect the ability of plant roots to absorb the nutrients they need for adequate growth.

At one time experts thought adding soil amendments such as elemental sulfur or acids would alter the pH of desert soils. However, these additions proved to have little effect, if any.

So what’s a gardener to do? The most important thing you can do for your vegetable garden soil is to add compost. This will alter the soil by increasing moisture holding capacity, drainage and provide necessary nutrients for plant growth. However, this is much more difficult to do for landscape plants, since the amount of organic matter needed for a mature tree’s root zone would involve excavation of an area at least 5 feet deep and 2 to 3 times the height of a mature plant. That’s a whole heck of a lot of soil to treat!

In landscape situations, the best solution is to plant natives. Native plants have developed a tolerance to alkaline soils, and will thrive without soil additives.

Another challenge of desert soil is caliche clay. You’ll know you’ve got it if you can’t dig through it. Caliche clay isn’t just hardpan, and there’s plenty of that around, this impenetrable layer requires a jackhammer to remove. Not only will roots not grow through this clay, but water will not permeate either. If you find the layer in the uppermost part of the soil, abandon the spot and plant elsewhere, or in the case of a vegetable garden, use raised beds. If you are planting a tree or shrub and find the layer at the bottom of the hole, as long as you punch through so water can drain, you’ll be fine. However, if you find caliche in the root zone (1-3 feet down), or you can’t get through it, don’t plant there.

Seed starting 101

My garden in early spring

Growing your own plants for your garden has several advantages. 

1. There is a wider selection of varieties including using organic seeds, hybrids that are best for your area, and heirlooms.

2. If you are planning a large garden, it is much less expensive to start from scratch.

3. You don’t have to worry about a nursery having the plants you want when you want them.

4. By putting the seedlings in a cold frame for several weeks before planting in the ground, you will have large healthy plants that do not need to be acclimated to full sun when you set them out in the garden.

You will need a south facing window, which will provide adequate sunlight to grow seedlings up to their first set of true leaves.  For my area, I start my seeds in early February for garden planting the first week of April. 

I use rubber warming mat (specifically designed for seeds) to keep seeds at a warm 85 degrees, and a seed starting plug system which has worked well for me for many years.  The plugs are made of sterile peat moss, and set in Styrofoam ‘cells’, which keep seeds moist at just the right level so they germinate without worry of damping off disease. 

Make sure you mist the seeds daily or more often as needed with warm water a 1 or 2 drops of liquid fertilizer per gallon.

Once the seeds have germinated and formed their true first leaves (the second set that forms), and have well established roots, you will need to boost them up to a larger container (a 12 oz Styrofoam cup with a hole poked in the bottom works well and lasts for many, many years) filled with regular potting soil.  From here they go into a cold frame until it’s time to plant. 

If you used a purchased cold frame, the most important thing to remember is that it cannot have glass for a lid.  The intense southwest sun will fry your tender seedlings in hours.  I use a piece of heavy floating row cover, which provides sun, but does not build up heat as glass does.

Do you need a cold frame? Maybe. Here's how to build one.

Nothing beats a homegrown tomato!

A cold frame is like a mini-greenhouse, essential if you intend to start plants from seed for a medium to large garden. Starting your own tomato seedlings allows you to grow larger and sturdier plants, ready to set out in the spring, for a lot less than it would cost to buy them ready to plant. This method also gives you greater flexibility with varieties you can’t find at the plant nursery. Planting heat tolerant tomato varieties is the key to tomato success in the desert southwest.

If you are handy with a circular saw, and like building things yourself, you can make a simple, functional cold frame starting with an old aluminum window.

Cold frames in cool climates have glass in the lid to keep seedlings warm.  In the desert southwest, that would be fatal as the heat buildup will kill the plants in one sunny afternoon. I use heavy weight “row cover” (aka Reemay cloth or season extender) material instead, and use giant binder clips to secure a piece over the window frame. 

The main concern for the plants inside is making sure they get plenty of sun during the day (but not intensified through glass), proper ventilation, and keeping them warm at night. To achieve this easily, you will need a greenhouse window opener, which automatically opens and closes the lid if it gets too warm inside, or too cold outside. They are not terribly expensive, and work great.  You will also need a mechanics drop light with a 75 watt bulb to hang inside to keep the plants warm at night. Use a timer to have the light come on from at least 10 p.m. to 8 a.m.. Keeping the seedlings warm, even it there aren’t freezing temperatures predicted, will make them grow strong and sturdy. If it is going to be exceptionally cold, I throw a blanket over the unit.

The size of your cold frame depends on how many seedlings you plan on having in there at one time. My unit holds more than 70 plants and measures 47” x 41” (the size of the old window I used). I made mine 2’ tall at the back, sloping to 8” in the front.  Make sure to add corner supports using 2 x 4’s.  You don’t need a bottom; just set it on the ground.

You will need hinges at the back so you can open the top and place seedlings inside. It helps to have a prop to hold the lid open while you are setting them inside or watering them—a piece of PVC pipe works well. Plants will need water every day, up to 2 times a day, depending on how warm it is outside.

You will want to face the cold frame to the south, where it will receive full sun all day. It may sound like a lot, but since you are setting them out in March, the days are not yet that long and you want all the sun you can get to grow strong plants.

Seed starting for tomatoes, peppers and eggplants should take place about 8 weeks before you intent to plant. (Stay tuned for article on how to start seeds.) After the average last frost date (April 1^st for Tucson, April 7^th for elevations 1000 feet higher), you can set out your new plants. I suggest you wait, even it the temps are mild. There is nothing worse then losing all of your hard work by a freak late spring storm.

Start planning for spring wildflowers now!

October and November are perfect for sowing desert wildflowers for a spring show, so it can’t hurt to plan ahead now. While some species do well starting from seeds, you can also shop around nurseries for seedlings. Just remember seedlings will need careful, frequent watering.

Preparing the planting area

Yes, they are wildflowers, but you can’t just toss them out in your yard and have them come up! Wildflower seeds are not cheap, so to ensure the best germination, you want to prepare an area for planting.

The perfect spot needs at least 6 to 8 hours of sun per day. Using a garden rake, loosen the soil about 1 inch down. To ensure good, even seed coverage, mix the seeds with sand, fine textured mulch or soil at a rate of 2 cups to 1 teaspoon of seed. Scatter the mixture and rake in lightly. Water the area with a sprinkler several times a week (skipping a rainy day if you are fortunate to get one or more). You may need to cover the area with burlap or straw to keep seed hungry birds away. After all, you want flowers, not a giant bird feeder.

Wildflower Options

Below are a number of varieties to try:

• Golden dyssoida (Dyssodia pentachaeta) has tiny yellow daisy-like flowers on plants reaching 6 inches tall and reseed themselves readily. They attract butterflies.
• Spreading fleabane (Erigeron divergens) grows to about 1 foot tall with white to pinkish daisy-like flowers. It also attracts butterflies and reseeds itself.
• Mexican gold poppy (Eschscholzia californica ssp. mexicana) also reseeds, and has golden yellow flowers.
• Red flax (Linum grandiflorum ‘Rubrum’) has bright red flowers on 2 foot tall plants.
• Blue flax (Linum lewisii) is also a 2 foot tall plant, but with blue flowers.
• Arroyo lupine (Lupinus succulentus) has violet-blue flower spikes on 3 foot tall plants.
• Five spot (Nemophila maculate) is an unusual wildflower with white petals sporting a purple spot on each. It reaches 8 inches tall and wide. Seeds are hard to find, but worth the effort.
• Desert bluebell (Phacelia campanularia) is a must have wildflower, with true blue flowers having you wonder if they are real. Desert bluebells grow to 1 foot tall and wide, and reseed.

After spring bloom, these plants will go to seed. You can either collect them to replant next year, or leave where they fall for another show. It’s best to do a little of both, in case the rains don’t cooperate or birds eat all of next year’s plants. Cut stems to the ground or pull out to neaten up the area.

Alternative weed killers

With all the rains we've had this summer, no doubt weeds are rampant. If your autopilot is on when you go to buy herbicide, turn it off and consider these alternatives instead.

Store bought cider vinegar is amazing stuff. Mix a squirt of dish soap to a gallon of vinegar to help it stick to leaves. This is acid, and will burn the leaves. You may have to spray difficult to kill weeds more than once (like Bermuda grass). There is also a more potent vinegar available. Horticultural Vinegar (at 20% acidity), available at Amazon.com. This usually works with one spray, and will certainly save you money over buying expensive and dangerous chemical herbicides. To apply, spray on small weeds (always best to get ‘em really small no matter what you use). Avoid spraying vinegar where you want plants to grow as it can alter the pH of the soil.

The Weed Dragon (brand name) works great on small GREEN weeds, especially around sidewalks, driveways and patios. It is available online and in some Ace Hardware stores. To kill weeds, you only need to run the flame over the weed until it wilts. The intent is not to actually burn them, just to burst the water in plant cells. The bonus is you will also kill weed seeds on the ground!

And then there is the good old fashioned Hula-ho, which works by slipping under the weed and minimally disturbing the soil. This hoe is better than the standard hoe for this reason, since the more soil you disturb, the more you bury weed seeds.

If you’ve got a particularly stubborn weed infested spot and want to kill off everything, cover the area with heavy duty CLEAR 4 or 5 mil plastic. Secure the edges and leave there for the entire summer. I guarantee nothing will be left by the end of August, including soil borne diseases. However, this will also kill beneficial insects, just so you know.

So before you buy chemical weed killer think about the cost to the environment and your budget. Alternatives are actually less expensive, and safer for you, your family, pets, and the planet.

Is there any such thing as rabbit-proof plants?

The leaves on spring flowering Chrysatinia are not tasty to rabbits.

Living in the outskirts of the Tucson area has many bonuses: open space, less traffic and pollution, and peace and quiet. You also probably enjoy the plentiful wildlife that lives in areas where natural vegetation was left undisturbed.

The other side of the coin is hungry critters will probably munch on your landscape plants, especially the cottontail rabbit. Maybe you heard about ‘rabbit-proof’ plants and had some success with certain species. While there are plants rabbits usually won’t eat, if hungry enough, they do eat just about anything unless it is poisonous.

Here is a partial list of plants rabbits often leave alone:

Barrel and columnar cactus

Cholla

Chrysactinia (Chrysactinia mexicana)

Trailing dalea (Dalea greggii)

Vinca major

Lantana species

Oleander

Red salvia (Salvia greggii)

Mexican oregano (Poliomintha maderensis ‘Lavender Spice’)

Rosemary

Germander

Note that what rabbits won’t eat in one yard they may eat in another. The best protection against rabbits is using chicken wire cages; unsightly, but it is the only thing that works. Pepper sprays, mothballs, garlic sprays and other “smell bad” products do not work. Sometimes rabbits will eat a newly introduced plant, only to leave it alone after it has been there for a while. The reasoning behind that is once certain plants are established, they manufacture chemicals in leaves and stems that taste nasty. Other plants you will need to protect forever, which is why you might want to keep those inside a patio wall or fenced yard.

It's fall planting time! Get your winter crops in the ground now

Mesquites provide just the right amount of filtered shade for herbs.

Fall is the best time to plant cool weather crops, including some herbs. Plan your fall garden like you would your spring garden; rotate crops and leave some empty spaces to give the soil a rest.

Garden Clean-up

If you had a spring garden, start cleaning up what isn’t doing well. Summer squash and melons are usually done by now, so unless you still have fruits on the vines, pull them out. Remove any dead, diseased or dying plants of any kind, too.

It is best not to compost plants from your garden, as in order to kill off insect eggs and diseases, your compost pile needs to reach temperatures above 200 degrees. It is not worth risking re-infecting your garden.

It is a good idea to add additional compost to your garden. Just keep in mind not to till too often, as you may end up killing all your beloved earthworms you worked so hard to bring in.

Seedlings for Fall Planting

Broccoli, cauliflower and cabbage work best this time of year when planted as seedlings. If your garden area is in full sun, they will appreciate some filtered shade to acclimate them to their new environment. Swiss chard, lettuce, kale and other greens can be purchase as seedlings, too, or you can plant seeds directly in the ground.

Vegetable Seeds for Fall Planting

Root crops like beets and carrots do not do well as transplants, so use seeds instead. Try different colored varieties like golden beets or purple carrots. Seeds of Change Beet Chioggia is also interesting, with a red and white striped interior. Other seeds to plant:

• Sugar snap peas- If you choose a bush sugar snap pea variety, you will not need to worry about installing a trellis. I usually wait until November or December to plant these.

• Lettuce-Slow bolt varieties like red oak and black-seeded simpson will ensure a longer crop.

• Kale-All kales do quite well. Even ornamental kale is edible.

• Swiss chard-Pick one with ruby red stems for more color.

Herbs to Plant in the Fall

• Parsley –Seeds of Change Parsley Italian Flatleaf or Parsley Forest Green are two organic options. Both are perennials and will continue to bring you fresh parsley for a year or two.

• Cilantro-Seeds of Change Cilantro Slow-Bolt ensures you will get the most out of your cilantro plants before they go to seed. Don’t forget to harvest the seeds; which are known as coriander.

• Chives- Plant Seeds of Change Chive Garden for snipping onion flavored stems to garnish your favorite recipes.

The best part about a fall garden is you don’t have to water as often, and there are few pests to contend with. Planting now means crops through early spring, and lots of fresh vegetables and herbs for your winter soup recipes.

10 top reasons to fire your landscaper

DO NOT let anyone prune your agave like this!

So you think your landscaper is doing a good job? Many people think as long as the person shows up, trims everything, rakes around the yard, and hauls trimmings away, they are doing a good job. Maybe. But if your landscaper is recommending any of the items below, it’s time to find someone else.

1.         They recommend topping your tree so it doesn’t block your, or your neighbor’s, views.

Nonsense! Topping does not only create rampant sucker growth, requiring even more pruning to keep it in check, but can lead to insect infestation, sunburn of exposed bark, disease, or even plant death. Not to mention how it will devalue not only your property, but your entire neighborhood’s home values. Don’t get me started as to how ugly this is, either.

2.         They shear your Texas Ranger shrubs into globes. Texas Rangers should never been sheared. Not only will all of the interior foliage die, but they are cutting off all of the lovely flowers. If the plant is too large for the space where it is planted, then take it out and plant either a smaller variety of Texas Ranger or a smaller plant. Period.

3.         They insist that snakes will live under your plants, and thus you must let them raise the plants off the ground: including cutting the leaves of agaves and desert spoons, effectively turning them into pineapples. This is ridiculous. We live in the desert, and so do snakes. Snakes are just as likely to curl up at your front door or under your car. The fact is: don’t stick appendages into places you can’t see.

4.         They recommend you feed your desert and desert adapted plants twice a year. Plants that are adapted to our desert soil rarely need fertilizer. In fact, if you feed plants in the legume family (and many of our desert plants are legumes), you will inhibit their natural ability to obtain nitrogen from the atmosphere. (Nitrogen fixation.) If your plant looks good, don’t feed it.

5.         They recommend dousing your agaves with poison to prevent the agave snout-nosed weevil from attacking your plants. Chemical insecticides are contact insecticides: which means you have to hit the bug with the chemical in order to kill it. Dumping poison on your plants to prevent the insect from doing damage does not work. It’s also wise to avoid using pesticides and insecticides at all, since they all end up polluting our groundwater.

6.         They tell you that if you let them cut the flower stalk off your agave, it will prolong its life. No, that is not true. Agaves flower at the end of their life cycle (about 30 years) and die. They will not live longer if you cut off the flower stalk.

7.         They offer to cut the arm off of your sahuaro because it is leaning and that will keep it from falling over. NO! Don’t do this. If your sahuaro is leaning, it could be because something is wrong with the roots. Make sure your sahuaro is NOT getting regular irrigation.

8.         If they tell you packrats will eat all of your flowers, don't believe them. Rabbits will, but packrats won't.

9.         If they insist covering your ground with landscape rock (gravel) will keep weeds from growing, they are wrong. It actually makes the weed problem worse because the seeds get trapped in the gravel where birds can't eat them.

10.     And last, but not least, they routinely cover your yard with Round-up weed killer. Don't let them do this! Round-up is poison. It ends up in your home, on your pet's paws, in your drinking water. Give them a hoe or tell them to use a vinegar and soap spray instead. It works, and is non-toxic.

Other vegetables for your desert garden

GROWING OTHER VEGETABLES

Sweet pepper ripen to several different colors

BEETS

Beets like cool weather, so plant seeds in late September. Standard red beets do fine, as do golden varieties. I like the golden beets because they don’t stain like red ones do.

BROCCOLI, CAULFLOWER AND CABBAGE

Starting these cruciferous vegetables from seed does work, but can be a bit challenging to start indoors in mid summer as there is usually not enough sun coming in a window to get them off to a good start and not too leggy.  I have had some success, but finally resorted to planting seeds in August, and keeping them shady until established.  Transplants work well too, but don’t set them out until September.  Provide shade so they can become acclimated as the sun is still pretty brutal.

Cabbage lopers are the main troublesome pest, so you will need to spray them with Bt (see Article 8; Biological Insect Controls) or hand pick.  They can decimate the leaves very quickly, so start spraying long before you see any signs of chewed leaves.

Harvest broccoli when the head is full and you just start to see a few yellow flowers.  This means it is as large as it will get.  Don’t let them go past that point, however, as they become bitter and tough.  Also, don’t pull the plant when you have harvested the main stalk, as they will continue to produce side shoots for months.

Harvest cauliflower before the head starts to open up.  You can tie the leaves over the head to keep it whiter, if desired.  Once harvested, the plant will not form another head, so you can remove the entire plant.

Cabbage should be picked while still compact and the leaves are tight.  Keep an eye out for cabbage lopers as they will work inside the leaves and eat the plant from the inside out. 

All of these only need to be protected from really hard frosts (into the teens).  Covering them with heavy duty polyester row covers will allow them to grow but keep them from freezing.  Remove the row covers if it starts to get too warm (over 85).  These plants prefer cooler weather.

CARROTS

Carrots like cool weather. Plant the seeds in late September. If the winter is too warm, they aren’t very sweet. Don’t expect to grow really long carrots here like you see in the store. Short varieties (like Nantes) are a good choice.

CORN

Corn is a summer crop. Growing corn is quite tricky and it requires a ton of attention.  Plant it in full sun after all danger of frost has passed, and in several rows.  Corn needs to cross-pollinate so a group of plants is much better than one long row.  Unless you are willing to hand pollinate (shaking the tassles over the silks), you will probably struggle getting ears to fill out.  Corn ear worms will drill holes in the tops and through the bottom, so you need to put mineral oil on the silk end weekly and use Bt for the exterior invasion. It also takes a lot more water than most crops.  However, if you are successful, you will have the best tasting corn ever.

CUCUMBERS

Cucumbers are a summer crop. Most standard cucumbers do not do well in the desert. The Armenian cucumber takes the heat very well, and produces long, crunchy fruits that do not need peeling. Keep an eye on them though, as they can grow several feet long if you let them.

Cucumber beetles can be a problem, and are difficult to control. I carry a bucket of soapy water around and shake the bugs off into the bucket.

EGGPLANT

Eggplants are spring planted. They do well here, but don’t expect to grow 2 to 3 pounders. They are usually much smaller here. Pick while their skin is still shiny purple to avoid seediness. The long Japanese eggplant is very prolific and a good choice.

Tomato hornworms will attack eggplants too, so spray the plants weekly with Bt.

GREENS (LETTUCE, KALE, ARUGULA, SWISS CHARD)

Fall is the time to plant greens in the desert southwest. There are many lettuce varieties to choose from, but I’ve always had excellent luck with Black Seeded Simpson which has frozen solid in cold winters but lived, and is the longest lasting lettuce when temperatures climb. It also easily reseeds itself if you let the plant go to seed. I haven’t had to plant lettuce in 10 years.

The only green I’ve had no luck with is spinach. If we have a mild winter, it bolts quickly or simply dies off.

PEPPERS

Sweet and hot peppers are planted in the spring. I love to pick sweet pepper varieties that ripen to a variety of colors. Look for red, orange, purple (black), and yellow.

Tomato hornworms will attack peppers too, so spray the plants weekly with Bt.

MELONS

Melons are a summer crop, and like rich soil, so compost is a must. There are very few pests that seem to bother them. Squash vine borers will sometimes attack them, but it is fairly rare.

I’ve had great success with the basic varieties of cantaloupe (no fancy hybrids for me). The Rocky Ford melon is delicious, and has green flesh. Honeydews need a very long growing season, which we have, and are harvested in late summer, early fall.

SUMMER SQUASH

Summer squash (like zucchini and scalloped squash (also known as patty pan) do extremely well here and are spring planted. The biggest pest is the squash vine borer. The telltale sign are holes drilled into the stems near the ground. You will see frass (what the borers leave behind) piled at the entrance hole. Once they have entered the plant, there really isn’t much you can do. I have read that you can split open the stem, remove the borer, and cover the incision with dirt. I have had no luck with this as the plant dies anyway. I have found the easiest and most effective thing to do is used Bt regularly.

Cucumber beetles can sometimes attack squash flowers. See the soapy water trick under “Cucumbers”.

WINTER SQUASH

Winter squash (pumpkins, butternut, acorn and others), do well, but prefer afternoon shade. Pumpkins will take over the garden, so give them lots of room. Squash vine borers also attack these, but butternut squash seem to be somewhat resistant, as the borers seem to prefer larger stemmed plants. Cucumber beetles will also attack the flowers, so see tip under “Cucumbers”.