April As the weather warms, we Tucsonans get busy in our gardens. PLANTING Plant color annuals such as pansies, petunias, larkspur and primrose. Plant warm-season flowering bulbs such as canna, dahlia, daylily and gladiolus. Set out warm-season annuals such as cosmos, four o’clock, globe amaranth, gloriosa daisy, lisianthus, marigold, portulaca, vinca, zinnia, celosia, salvia, sunflower, gaillardia, beans, okra, cucumber, peanut, pumpkin, melon and squash. Plant seedlings of pepper, tomatoes, squash, eggplant and green onion. Sow seeds for warm-season flowers such as gaillardia, hollyhock, salvia, sunflowers, tithonia and zinnia in garden beds. PRUNING Look for new growth on native and desertadapted plants. Prune winter-damaged plant parts. Allow flower stalks on spring bulbs to brown and die back naturally. When spent, clip off at the base. FERTILIZING Watch for iron deficiency on citrus, pyracantha, gardenia, nandina and bottlebrush. Look for yellow leaves with green veins, which signal gardeners to apply chelated iron according to package directions. Always water before and after applying any fertilizer. Feed Bermuda grass with high-nitrogen fertilizer. Feed roses every two weeks or use a slowrelease fertilizer for longer season intervals during spring’s peak bloom. PREPARING Reap flower seeds. Allow wildflowers and cool-season annual flowers to dry and scatter seed; or collect dry seed and store to sow next fall. WATERING Adjust drip-irrigation systems to accommodate new plants and the warming temperatures. TRANSPLANTING Plant red bird of paradise, ageratum, eupatorium, passion vine, desert hackberry and datura to attract butterflies. Plant container-grown roses. Plant new citrus and protect trunks from sunburn. Don’t fertilize when flowering. Plant desert landscape shrubs, cacti and succulents so that the roots re-establish before the summer heat. TIP OF THE MONTH Oxalis species often are sold as “shamrock plants” due to their clover-like leaves that close up at night. They are easy to grow, indoors and out, and are propagated from tiny bulbs. Leaves of the Oxalis appear in a range of colors from the most common green to purple. Look for unusual cultivars in variegated colors and a variety of leaf shapes. The attractive star-shape blooms can be found in shades of yellow, pink, purple and white. Outdoors they can be grown in partial or full shade in well-drained soil, either in-ground or in pots. Indoors, some Oxalis varieties will bloom all year if given enough light. After blooming has finished, leave the foliage in place. The leaves will gather sunlight, creating food through photosynthesis and strengthening the bulb for the future. They will yellow and die back as the plant slips into dormancy. The plants will rest before beginning their next growing cycle.