Plant Milkweeds for Monarchs
Monarch butterflies travel up to 3000 miles between their warm winter roosting spots in Mexico and California and summer living quarters as far north as Canada. Gardeners can lure them to their yards as well as help make up for loss of habitat along their migration route by planting milkweeds (Asclepias spp). Monarchs lay their eggs on milkweeds and will seek out even tiny backyard gardens if milkweeds are available. These four milkweeds thrive in the low desert: Asclepias angustifolia, A. curassavica, A. linaria, and A. subulata. Mid and high elevation options include: Asclepias asperula, A. engelmanniana, A. nyctaginifolia, A. speciosa, A. subverticillata and A. tuberosa. A. linaria also grows at mid elevations and A. latifolia at high ones.
Add Landscape Plants
March is a great month to add plants to low desert landscapes, including trees, shrubs, vines, ground covers, ornamental grasses, perennials, cacti, and succulents. Choosing the Right Plant for the Right Space is a horticultural mantra that simply means matching each plant's required sun exposure to what your landscape offers, and installing plants where they have room to reach their mature size without encroaching on sidewalks, paths, rooftops, and so on. Determine the vertical and horizontal space you have available for different planting areas before heading off to nurseries and plant sales.
Transplant Tomatoes and Peppers
If you haven't transplanted tomatoes yet in the low desert, get them in the ground as soon as possible. (Be prepared to protect them during any late frosts.) Inexperienced gardeners often wait too long to transplant, and the plants don't have time to establish, flower, and produce luscious tomatoes. Pollen isn't viable over 90 degrees, so no fruit will set after heat arrives in May. Peppers are a little more forgiving, but transplant them now as well. At mid elevations, transplant from mid-March to mid-April. At higher desert elevations, transplant after your last frost date, usually between May 1 to June 1.
Feed Deciduous Fruit Trees
Fertilizer stimulates tender new growth that is susceptible to frost damage. Wait to apply nitrogen until your frost season has passed and buds begin to swell. Fertilizer applied before the tree is growing won't be absorbed by the roots and is wasted. Water deeply immediately after applying.
April is the prime month for rose blooms in the low desert. Prepare them for this flowering frenzy by feeding every six weeks or so, tapering off as summer heat hits in June. A slow-release product works well if you are busy or forgetful! To maximize bloom, supplement with liquid feedings every week or two. Roses perform well in the desert with proper care, although they may sometimes experience magnesium deficiency. Many local rosarians add one-quarter cup of epsom salts (magnesium sulfate) per bush to help prevent magnesium deficiency. Water soil deeply through the root zone after applying any fertilizers to prevent root burn.