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| 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.
