Think Like A Plant

Before you buy that plant and stick it in the ground, do your home work and think like a plant. Many people come to the southwestern United States from other places. Most of these other places have more rainfall, more established soils, less direct sun, higher humidity and lower winds. You must consider these attributes if you want to garden successfully in the southwestern United States. These conditions make our area a fascinating place for plants. Because we have so little rainfall, the soils here tend to be alkaline. You must also be very careful to be consistent in watering regimes, especially until the plant has become well-established. Sometimes, even for natives, it may take two or three years for them to become completely established. The climate and weather here is highly variable. Check on the last and first days of frost, recognizing that we have a lot of variability, from year to year.

Do your home work.

  • What is your exposure? East/west/south/north? It makes a big difference, because orientation tells you when the sun hits your plants during the day and during the year.
  • How much sun? Consider shade from building and other plants. Most books or resources on the internet will tell you the light requirements for your plant, in terms of hours per day. Or they will give you valuable clues, such as “full sun” or “partial shade.”
  • Slope? It is difficult to garden on a steep slope. You may need to consider terracing. If you are at the bottom of a slope, you may be subject to cold air flowing down the slope, especially at night. You will then have a shorter growing season, with earlier and later frosts than your uphill neighbors, even if they are only a few hundred feet away.
  • Soil? The soil is your plant’s home. Natives to the Chihuahuan Desert and Uplands prefer alkaline soil. However, if you are trying to grow roses or a vegetable garden, you wil have to add amendments to make it more accidic. Compost, composted cotton burs or sulfur will help bring the pH down to a more comfortable level for these plants that evolved elsewhere.
  • Drainage? You also need to know how well the water will drain. Sandy soils drain fast and will require more water. Heavy soils, with more clay, will drain more slowly. You might dig a hole in clay soil and find that your plant drowns in the hole, because the water wil not drain. Adding organic matter, like compost, leaf litter or composted cottonseed burs to sandy soils or the clayey soils will help them.
  • Microclimates? Learn your micro-climates. Check where the snow is, immediately after it snows. Where does it melt first? What stays frozen? Rock or masonry wals, especially those facing east, south or west, can hold the heat during the winter and help prevent frost damage. What direction are your prevailing winds? You might need to consider a wind break.
  • Where does your plant come from? If it’s native to the Sonoran or Mojave Desert, it may not do well here in the Chihuahuan Desert. We get summer rain and drier winters. The Mojave (in southern California) gets wet winters and dry summers. Sonoran (Arizona) is in between. Also check the elevation of your supplying nursery. [Note: If you buy plants from the Gila Native Plant Society, we tend to buy from Mountain States growers in Phoenix. So, plants that you pick up in the Spring from GNPS might be a little cold-shocked when they come to Silver City. You might want to put them on a porch, a garage or other protected area until they acclimate.]

When selecting tress for your yard, this is a case where bigger is NOT better. The perfect size tree to select for planting in your yard is no more than 4 feet tall. Otherwise, it will have a matted-up root ball and it will take several years for it to recover. By that time, a smaller tree would now be better established and taller. If you find matted roots in the root ball, do not cut them. You must untangle them if you want your transplanted tree to grow.

Avoid buying large perennials. One gallon pots usually do better than larger sizes, for the same reason as the trees. Even though they look pretty, avoid plants with flowers in bloom. Once you plant them, the blooms will all fall off. If you have to buy plants with blooms, buy a plant that has more greenery. Before planting, cut the flowers off. The flowers use a lot of water and nutrients. You want the plant to spend its energy and water on developing roots, not seeds.

When planting cactus, this is where bigger IS better. Young cactus are very susceptible to burning and predation. If you look in nature, most cactus get started under a shrub or bush. The small ones have not yet developed their spiny defense against herbivores.

Planting tips for trees (and other plants)
Dig a square hole, twice as big as the pot. Square holes have corners, which help defeat the clayey soils we have. Clay minerals are flat and plate-like. When you put a shovel in the ground, all the clay plates go from horizontal to vertical, making a tight seal that the roots can’t penetrate. Use hydrogen peroxide to treat the hole, because it reacts and disolves the clay. Spray about one small bottle around the edges of a big hole. Scratch the sides with a small hand cultivator. When you plant, make sure that the plants will end up at the same level as the soil in the pot. You don’t really need soil amendments, like fertilizer, for natives. But don’t forget to mulch; it’s the best water saver you can have. Use a 50 foot soaker hose, coiled around the tree’s trunk, 8” apart to get a good soaking and to encourage the roots to extend. Let roots dry out in between. After the first year, cut back on watering.

Leaf litter is the best, but it’s not the most attractive. Cottonseed burs are good. Bark mulch is okay. Even gravel is good, especially for cactus and desert plants. (agaves, etc). Straw is good. Do not use sawdust, as it mats up and repels water.

Staking of trees
Don’t do it, if at all possible. Trees need to move in the wind, because the movement stimulates the tree to build up woody growth. Remove the stake that the grower has placed in the pot. See if the tree will be okay without it. If it whips a lot, so that the roots are exposed, then you need to stake it. T posts, with flexible green garden tape, are best.

You must water until the plant is established. Even if the plant is drought tolerant, it still needs water to get established. The first year is the most crucial. Just because it is dormant, it isn’t dead. Test with your finger to see how dry the soil is. Use the following watering guidelines, assuming you plant is mulched. This schedule assumes that you have planted in the Fall, which is the optimal time for planting, especially in our area. It still works, even if you planted in the Spring.

Winter (dormant season)
Every three to four weeks, water well. Conifers must be watered more frequently during the winter. Plants that do not need winter water: Texas Rangers, Chihuahua Desert natives, cactus, yuccas, agaves.

Start to water every two weeks or so. Don’t water too much at the start, or you will encourage too much growth too early, and the plant wil be susceptible to our late frosts, so common to our area. By May, you can water more. Spring is not the best time to plant. Late summer or early fall are preferred

June and July. It’s hot and dry here in Silver City, the home of the Gila Native Plant Society. Water once or twice per week, depending on the plant. You may see the plant wilting and your soil is damp. This is because the roots pump enough water to the meet the demands of the foliage. We have very low humidity, which makes the plants transpire (use water) a lot. You might consider trimming some of the greenery, to compensate. It may also be that we have had an exceptionally dry summer. Or, you may have the plant in too much sun.

You should not have to water during this season. But the rains are notoriously spotty. So use your rain guage to know how much water your yard is getting. If the rain guage has less than ¼ inch, water that day. Also, test the soil. Dig through the mulch and feel if it’s damp. If dry, water.

This season is the optimal time to plant. Roots can really get well-established. Taper off the water at the end of the season. This will help your plants harden off. This hardening off is especialy important for Desert Willow. You must let it harden off, so back off on the water. And don’t panic if your Desert Willow seems dead in the spring. It also leafs out late.

Infrequent, but deep soaking.

Don’t. Use compost or mulch. Our soils are deficient in iron, because the alkalinity makes the iron insoluble and, therefore, inaccessible to the plants. Try epsom salts, one tablespoon sprinkled around the soil under a plant the size of a rose bush. Adjust the amount, depending on the size of the plant you are treating. Epsom salts have magnesium (used to make chlorophyll) and sulfur, which combats the alkalinity. Epsom salts are especially good for fruit trees and roses.

Don’t spray or treat, until you know what pest you have. If you have insects, capture some and observe their habits. If the foliage looks sick, gather some affected leaves. Most good hardware stores have a copy of the Ortho Book on Gardening. You can usually identify the pest (insect, virus, fungus, etc) from the book. Then use the most eco-friendly treatment you can. Remember, insecticides are broad spectrum and will kill everything, even the good guys.

County Extension Service
This group is part of the US Department of Agriculture and has talented and knowledgeable staff. Consult them when you have questions.