Amend Garden Soil
Layer 4 to 6 inches of organic matter, such as compost or well-aged manure, on top of the soil. Either soil sulfur or gypsum can be added to temporarily reduce soil pH on a limited basis and improve drainage. Add nitrogen and phosphorus fertilizer. Most desert soils contain sufficient potassium, so it isn't necessary to include it, but check with your county cooperative extension office for soil types in your area. Follow package instructions for the amount of fertilizer and amendments to add. Turn it all under to a depth of 12 to 18 inches.
Water Deciduous Fruit Trees
These trees need consistent soil moisture to develop fruit with adequate size during April and May. Water should penetrate 3 feet deep and be applied at the edge of the foliage canopy or dripline, where feeder roots are absorbing water and nutrients. Move emitters or bubblers outward as the tree grows.
Plant Annual Flowers
Sow seeds for warm-season annuals including coreopsis, cosmos, dianthus, impatiens, lisianthus, marigolds, purslane, salvia, sunflowers, Mexican sunflowers, and zinnias. Plant in improved soil and keep consistently moist until seeds germinate. Gradually reduce watering as seedlings become established.
Give saguaro cactus a close inspection, looking for oozing, black, smelly areas that indicate bacterial necrosis. If found, treat immediately or it can kill the cactus. Use a sterile, sharp knife to cut out all of the rot. Healthy tissue will be light and firm, resembling a raw potato. Dispose of the rot in the garbage. Rinse out the wound with a solution of 1 part bleach to 9 parts water. Let the area dry and callus over naturally.
Clean Up Citrus
Harvest grapefruit, lemons, limes, and Valencia oranges. Clean up any fallen fruit from around the tree. Roof rats are becoming a problem in neighborhoods that have lots of citrus trees bearing fruit that isn\'t harvested or cleaned up. The rats come for the fruit. At this time of year there may be mature fruit as well as small immature citrus that are dropped as part of the trees\' natural thinning process. If you don\'t have time to harvest, call a food bank. They often have gleaners who will harvest the fruit so it doesn\'t go to waste.