Get ready to turn the corner into summer
Already SPEEDING along, spring gets a turbo-like boost in May as ever more comes into bloom. Much of what you see can be planted now, because the next six weeks are typically overcast and on the cool side. This gives newcomers to the garden time to get established before the heat of summer slams this planting window shut. Just make sure you don’t buy spring-blooming bedding plants that are about to call it quits. Instead, look for perennials or bedding plants that bloom all summer.
Easy pickings
Because so many bloom this month, perennials are plentiful at nurseries, though there are kinds that flower in summer and fall, plus those that are grown for their foliage, such as lamb’s ears and Helichrysum ‘Limelight.’ Perennials are the dramatic middle ground in gardens, generally taller and longer lived than bedding plants so they can be counted on for more than a few years, yet they are not as woody or long-lived as shrubs.
Summer sizzlers
Continue planting summer color such as ageratum, celosia, bedding dahlia, gloriosa daisy, marigold, petunia, portulaca, verbena and zinnia. In the shade, try bedding begonias, browallia, caladiums, coleus, impatiens, mimulus and forget-me-not. These are some of the brightest flowers you can grow, and all do as well in pots as they do in the ground.
Mulch month
To keep baked summer soils from cracking and becoming almost water repellent, keep the dirt between plants covered with a light mulch of chipped tree trimmings, coarse compost or shredded bark (not chunky bark, which harbors pests and encourages weeds). Mulches also save water, moderate soil temperatures and keep down dust. Or lightly and shallowly cultivate the soil surface between irrigations. Don’t cultivate deeper than an inch or around roses or camellias, both of which have shallow roots.
Plant a jungle
It’s the perfect time to put in subtropicals such as hibiscus and bougainvillea or gingers and bananas, since they will grow quickly in the warming weather. Most will need a fair amount of water to get started, but many are quite tolerant of dry spells once established, despite their jungle looks. Mature bougainvilleas actually bloom best with little or no summer water.
Fixin’s for a picnic
If you haven’t already done so, it’s time to plant those main-crop tomatoes -- the beefsteaks, Big Boys and other burger-smothering slicers. You’ll want some corn to go with those barbecued burgers, and don’t forget peppers, one of the most versatile summer crops. Other edibles to plant now include beet, carrot, chayote, cucumber, leaf lettuce, melons, New Zealand spinach, onion, pumpkin, radish, squash, sunflower and Swiss chard.
Not now for natives
Although native shrubs and wildflowers continue to bloom and look their finest, most should not be planted at this time of year. It is difficult to keep new ones alive in summer without constantly watering them, and keeping natives too moist can kill them. If you buy one, consider keeping it in its pot and then planting it in late autumn. The exceptions: those natives from wetter parts of the state such as Pacific Coast iris.
Perennials
Spring-blooming: Alstroemeria, armeria, bearded iris, brachycome, campanula, columbine, convolvulus, coral bells, true geraniums, nicotiana, phlomis, scabiosa, shrimp plant, sunrose and veronica.
Summer-blooming: Agapanthus, bidens, coreopsis, daylily, gaillardia, heliotrope, lion’s tail (Leonotis), penstemon, salvia, Shasta daisy, tulbaghia, Verbena bonariensis and V. rigida and yarrow.
Fall-blooming: Gayfeather (Liatris), helianthus, Japanese anemone, physostegia, Sedum ‘Autumn Joy’ and Tagetes lucida.
