Xeriscape – Drought-Adaptive Horticulture
Gardening in West Texas...
Stresses, Part 2
INSECTS
With native plants, I have had few problems. The most important is a tiny worm that has invaded Desert Willow and Salvia blossoms, preventing their opening. Grasshoppers have stripped leaves off a number of things, but only Madrone did not recover.
Many insect problems I ascribe to poor cultural practices. Scale on hedges comes from the plants being too close together, and being weak from competition, are then open to infestation. It is the same story, mealybugs on various plants, whiteflies on everything except grapes which get whiteflies no matter what… and so on. My first line of defense is to water less, and water deeper when I do.
Overall, I have been blessed with few bugs- but I stopped vegetable gardening because of a never seen bug that caused the vegies to ripen at the point of damage, and then be rotten by the time the rest ripened. Squash bugs are a fact of life- there is no stopping them. Tomato hornworms get tossed into the pasture… and butterfly caterpillars are sacrificed if too many of them are severely stripping a plant. (I lost a passionvine for a couple of years by not doing that.)
WEEDS
Nightshade, Johnson grass, and climbing milkweed are attacked when seen- supposedly after several years of yanking they die out. Groundcherry and sida do disappear after several pullings. Native grasses are the most common unwanted visitor in my beds- but are easily pulled. Sandbur, goathead, careless weed, tumbleweed, kochia, marestail, and other annual weeds have been rare because I never leave the soil bare in a bed. I leave any wildflower- including onions, that may have some sort of flower- I consider them blessings instead of pests. I have not had nutgrass because I have not imported soil that I did not personally inspect. Bermuda grass in beds I attack with Poast, newspaper and cottonseed mulch, but it is often a continual battle. At the pond, I am trying to learn to live with it. Knotroot bristlegrass has been a problem- I pull it when I see it, but I must always miss some, for it shows the next year. Rescue grass I leave as a winter cover crop. Annual bluegrass and other town weeds in beds have never appeared, probably because of mulch.
DISEASE
Diseases appear and disappear, and often the causes for either are hard to figure out. I lost Russian Olive to cottony root rot. I lost two specimens of one species of Juniper one year, but never again, to an unknown disease. I have had few diseases, probably due to pushing the watering to minimal amounts required. Occasionally various leaf spots and rusts show up, but only as blemishes to the appearance of leaves in a particular species. Powdery mildew has appeared on mass plantings of coralberry in rainy summers, but not on individual plants.
SALTY SOIL AND WATER
Our soil is around 8.0 pH, and our water up to 8.5 pH. Some plants just can not live in these conditions. If a plant never starts growing, and slowly declines until death, that plant probably can not be grown here without drastic measures. Bleeding hearts and gardenias are examples of plants that decline from the day installed. Iron chlorosis shows up on a number of plants, and with soil acidifiers one can somewhat maintain the conditions needed, but it usually prolongs the battle. Crepe myrtles show chlorisis after blooming, but do not in the spring (usually), and the plant maintains vigor, so the cruddy look of the leaves in late summer are something to just accept. If one waters a bed for years, without ever topdressing or mulching, the salts collect in the soil, and the soil becomes compacted. This is easily avoided by constantly having several inches of mulch on the ground, and adding composted manures and other organics.