April in a Desert Garden
Every year my senses are overwhelmed with the sounds, colors, and fragrance of spring as our desert reaches its fullest potential! As we are starting to wind down our garden tasks for the slower pace of summer, it is important that before the heat or you leave for the season, you complete some basic maintenance checks on your yard and irrigation.
Topics covered: Planting, Pruning, Flowering, Vegetables, Irrigation, Pests, Weeds, and Fertilizer
In the desert, we do major pruning in October and February so you shouldn't be doing any major pruning this month. You always want to be looking at your plants though and only trimming problem areas. Is there a branch in your pathway or do you have a dead branch that needs to be taken out? This keeps you from having to do as much later and corrects issues before they become major problems.
For spring flowering shrubs like Sennas and Texas Rangers, once they have stopped, you can thin them lightly to control size.
Cut back any Chollas or Prickly Pears that are too large.
The desert will reach its full color this month! Desert Marigold, Desert Milkweek, California Poppy, Evening Primrose, Penstemon, Globemallow, everything will be in bloom!
You want to continue to deadhead some flowers to promote a prolonged bloom. I leave the majority of my spent blooms as seeds for wildlife.
Collect seeds for next year as soon as the seedpod begins to turn brown or dry out. Store in a paper bag and allow to dry out for a week or two in a dry shady spot. If you want a more natural landscape, allow the seeds to drop naturally.
Pests, Weeds, and Fertilizer
PESTS: prevention is the best method for a pest-free garden.
Drip irrigation, watering the plants from below rather than spraying the leaves helps prevent disease keeping the plant healthy. Healthy plants equal fewer pests.
Treat the first signs of mealy bugs with a q-tip dipped in alcohol. A large infestation is difficult to control without chemical intervention.
Have you seen a white frothy foam on the new growth of your plants? This is protection for the nymph of the spittlebug. They are relatively harmless but you can remove them with a strong jet from the hose.
One of our native bees, the Carpenter bee is becoming active this month. They are excellent pollinators and should not be considered pests!
WEEDS: don't put off weeding! Regular maintenance prevents spread.
Spurge weed, (Euphorbia maculata) is popping up now that the weather is warm. Once you have an infestation of this it is difficult to get rid of it. Hand pulling, making sure to remove the tap root, and the use of thick mulch to starve the seedlings of light are the most effective removal methods in my experience. Use gloves when handling spurge. The milky sap can cause irritation in some people.
FERTILIZE: desert plants do not need regular doses of fertilizer if they are growing in the ground. But they do benefit from a 3-4 inch layer of compost or mulch. This will help keep the soil cooler, cut down on evaporation loss, and provides ample nutrients.
You can continue to plant your warm season crops like squash, melons, pumpkins, and cucumbers.
A personal favorite of mine is Armenian cucumbers. They grow here much more reliably than traditional cucumbers. They also never have the bitter taste that cucumbers get when they are under stress because they are actually in the melon family and do not have cucurbitacin.
Melons should be started as early as possible so that they are ripening before it gets too hot.
Most herbs can still be started this month.
Know your plant before you fertilize. Root vegetables only need fertilization at the beginning and halfway through their growing season. Overfertilization will result in lots of top growth and little root development.
Fast-growing vegetables that you eat the flowers or leaves can be fertilized every 2-4 weeks with a fish emulsion or sea kelp.
Do not fertilize winter growing herbs until fall.
To extend your tomato harvest, add shade, mulch, and water deeply but less frequently. You want the roots to go down deep into the cool soil where it takes longer to dry out.
If using annuals for color, consider replacing them with natives. Now is an excellent time to look at your landscape and decide what you could swap out.
April is the last month for planting until fall. Be cautious when planting in full-sun western exposures this late though. This is the most extreme heat and you want your plants to have time to acclimate prior to summer temperatures.
If you did not review your irrigation system in March, do so now.
Increase water to accommodate warmer temperatures. Water deeply but infrequently to prevent plants from becoming overgrown, floppy, or subject to rot. Remember, desert natives, want to have deep waterings and then dry out in between.
If you leave for the summer, make sure to check your irrigation system before you go for leaks, clogged emitters, etc.
Refresh the water basins and mulch around your trees and plants before the summer heat.