Regional Growing Guide: Southwestern Deserts
From the sunny beaches of California to the blistering deserts of the Southwest, this region is marked by nearly year-round sunshine and little rain. Roses bloom from April through December in the more temperate parts, while they take a rest during August and September in the great deserts, where searing temperatures vary little between day and night. There, roses have two seasons: spring and fall, with peak blooming in April and October. Ample irrigation is key. Soils may be alkaline or sand: it's important to amend with plenty of organic matter. The best roses are heat tolerant, and tend to bear darker leaves and bloom in more intensely saturated colors.
Select a season: Spring Early Summer Late Summer Fall
Prepare Flower Beds
In sprintime, garden tours are in full swing in the low desert. Flower beds are bursting with color, aided by rains alternating with warm temperatures. It's fun to see what other plantaholics are growing.
Soil preparation is crucial to growing roses in the desert. The ideal growing environment has 18 inches of loosened and improved soil. You may need a pick ax and shovel to dig beds in the may-as-well-be-rock soil. Or, you may decide that raised beds are the way to go.
Add Compost
Whichever you choose, spread a 4- to 6-inch layer of compost on top of the bed. Compost is often called "gardener's gold" for all the wonderful benefits it provides. In clay soil it improves drainage. In sandy soil it improves water and fertilizer retention. Compost adds nutrients to the soil, enhances its overall workability, encourages soil microbial activity, and provides a hospitable environment for earthworms, who will do some of the work of soil building for you.
Add Fertilizer and Soil Amendments
Desert soils typically have plenty of potassium, so only nitrogen and phosphorus need to be added. Ammonium phosphate (16-20-0) is a standard choice. Choose organic fertilizers, such as blood meal, fish emulsion, and seabird guano for nitrogen; and bone meal or rock phosphate for phosphorus. Either soil sulfur or gypsum can be added to improve drainage. Follow package instructions for any fertilizer or amendment.
Dig In!
Turn it all under, incorporating the compost, fertilizer, and amendments into the soil. Rake it smooth. Don't walk on the soil unless necessary to prevent compaction. Some folks like to let a bed "sit" for a few weeks, watering it and pulling any weeds that appear.