What to do in your garden in May
• Daylilies. For a long season of blooms with little effort, grow daylilies. ‘Persian Market’ and ‘Buttered Popcorn’, two All-American varieties, are especially floriferous. The first is salmon pink, the second vibrant gold. ‘Frankly Scarlet’, a 2003 winner, is another strong performer in Southern California. ‘Stella de Oro’, though often sold at nurseries here, doesn’t do well in our climate.
• Other summer perennials. For beautiful blooms on plants that thrive with modest amounts of water and care, set out gaillardia, gaura, gazania, lion’s tail, rudbeckia, salvias, Shasta daisies, and verbena. All are sturdy additions to the summer garden. For the lovely fragrance of vanilla in a patio pot, choose purple-flowered heliotrope. Pentas, another great choice for Southern California, has clusters of star-shaped flowers in shades of bright red, pink,lilac, or white.
• Vegetables. Set out eggplant, pepper, and tomato plants. To find unusual varieties, if your local nursery doesn’t carry them, order plants from the Natural Gardening Company (707/766-9303), based in Petaluma. Sow seeds of beans, cucumber, corn, melons, and squash directly in the ground. Baker Creek Heirloom Seeds (417/924-8917) is a good source for unusual varieties.
• Fertilize. Feed azaleas and camellias when they finish blooming. Use an acid-type fertilizer designed for them. Or make your own, combining 4 parts cottonseed meal and 1 part chelated iron. Give subtropicals high-nitrogen food when they put out new growth. Fertilize all lawns this month; it should be the first application this year for warm-season grasses (such as Bermuda) and the last until the fall for cool-season grasses (like fescue). Don’t forget to feed houseplants; they’re growing again too.
• Prune. If abutilon, hibiscus, princess flower, and other subtropical shrubs have become leggy, cut them back by as much as half.
PESTS AND DISEASES
• Control rose slugs. Sawflies begin laying their eggs on rose leaves in spring. When they hatch, the larvae ―called rose slugs ― feed on the leaves, creating a skeletonized appearance. To control damage, start inspecting the underside of rose foliage weekly, looking for pale green, caterpillar-like bodies. Squash the larvae with your fingers, wash them off with a forceful spray of water from the hose, or remove the affected leaves. If the infestation is widespread, apply the contact insecticide Spinosad; spray the undersides of the leaves thoroughly.
• Look out for citrus root weevil. Diaprepes abbreviatus, a weevil that feeds on the roots of more than 270 species of host plants, including citrus, has appeared in a few isolated locations in Orange and Los Angeles Counties. If it spreads, it will be a significant threat to agriculture and landscaping. For more information, as well as photos, visit the California Department of Food and Agriculture’s website. If you find an insect that meets the description, call this hotline: 800/491-1899.