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”.