Southwest April checklist

PLANTING

• Citrus. Sunset climate zones 12 and 13: Plant blood orange, grapefruit, kumquat, lemon, mandarin, orange, pummelo, and tangelo. 1a-3b, 10-11: Grow 'Bearss' lime, 'Improved Meyer' lemon, or 'Mexican' thornless lime in a large container and move it indoors before winter arrives.

• Herbs. Set out seedlings of anise hyssop, basil, bay laurel, chives, lemon grass, mint, oregano, rosemary, sage, salad burnet, and thyme. One good source is Companion Plants (740/592-4643).

• Hibiscus. If you like the bold flowers of tropical hibiscus (Hibiscus rosa-sinensis), the exceptional colors and denser foliage of two new ones will thrill you. 'Cool Wind' stays a petite 2 to 3 feet tall, is great for patios and pots, and produces huge numbers of white flowers with pink centers. 'Starry Wind' grows 5 to 10 feet tall and produces dozens of orange-red flowers. Both thrive in full sun and are hardy to 32° (protect during cold snaps).

• Native plants. Three species to look for are Wright's milkpea (Galactia wrightii), a delicate vine with pink flowers; Guardiola platyphylla, a sunflower relative that attracts butterflies and birds; and Mexican passionflower (Passiflora mexicana), a vigorous vine with unusual green flowers that have rings of red filaments that fade to pale violet. Plants are available at Tohono Chul Park (520/742-6455) in Tucson or at some nurseries.

• Vegetables. Zones 1a-3b: Set out transplants of broccoli, cabbage, chard, and kale. Sow seeds of beets, carrots, salad greens, and spinach. Zone 10: Set out transplants of eggplant, peppers, and tomatoes. Sow seeds of beans, cucumbers, melons, and squash. Zones 11-13: Set out transplants of eggplant, peppers, and tomatoes. Sow seeds of beans, carrots, corn, cucumbers, melons, and squash. One good seed source is Plants of the Southwest (800/788-7333).

• Wildflowers. Check out Wildflowers of Tucson or Chihuahuan Desert Plants for close-up photos and detailed information about wildflowers that grow throughout the Southwest. Bloom time varies from spring through fall.

MAINTENANCE

• Adjust irrigation timers. As temperatures increase, so do the water needs of your garden. To give plants just the right amount, adjust the timer by increasing the number of days per week it operates, but not the number of minutes per cycle.

• Control flea beetles. These small hard-shell insects produce tiny holes in the foliage and flowers of Mexican evening primrose and other leafy plants. To treat, spray plants with insecticidal soap twice daily until damage abates.

• Fertilize. Feed established plants (including roses) and lawns with a balanced fertilizer. Feed palms with a fertilizer formulated specifically for them. To avoid burning roots, water thoroughly before and after applications.

• Mulch. Spread a 3- to 4-inch layer of compost, bark chips, forest mulch, or other organic matter around plants to help retain soil moisture and keep it cooler. Organic matter also benefits the soil as it breaks down.

GROW PENSTEMONS

Sunset climate zones 2b, 3a, and 10–13: These beautiful, water-thrifty perennials draw hummingbirds. Try P. ambiguus, P. barbatus, P. eatonii, P. pinifolius, and P. strictus; all are available from Plants of the Southwest (800/788-7333).

SET OUT VEGETABLES

Zones 1a–3b: Set out plants of broccoli, cabbage, chard, and kale. Sow seeds of beets, carrots, and salad greens. Zone 10: Plant seedlings of eggplant, peppers, and tomatoes; sow seeds of beans, corn, cucumbers, melons, okra, radishes, and squash. Zones 11–13: Start plants of eggplant, peppers, and tomatoes. Sow seeds of carrots, cucumbers, green onions, lima and snap beans, and squash.

TRY A NEW AGAVE

Zones 12–13: Plant striking ‘Blue Glow’ (A. attenuata x A. ocahui ‘Blue Glow’), which has deep blue-green leaves with maroon leaf margins, is hardy to 15°, and forms a 3- by 3-foot rosette. Find it at B&B Cactus Farm in Tucson (520/721-4687).