April is the time to plant tomatoes, citrus and summer flowers

It’s finally warm enough for those April gardening opportunities, including planting tomatoes in most parts of the Southland, or petunias, or citrus and other warmth-loving plants. Putting them in now gives the plants time to become established before the heat of summer arrives. Be sure to set aside time to smell the roses and other flowers – at home and at botanic gardens – because everything’s in bloom.

Rose renewal

The April bloom on roses is spectacular – usually the best of the year – and roses will keep blooming every six weeks or so if the spent flowers are promptly cut off and the plants fed. Make the cuts right above an outward-facing leaf, far enough down on the stem to ensure strong new sprouts. Don’t just cut off the flower. Make the cut just above what’s called a “five-part leaf” – a leaf divided into five leaflets. Use a rose fertilizer and lightly cultivate it into the soil.

Watch for the tiny holes in leaves caused by sawfly larva (rose “slugs”) and control organically with horticultural oil sprays.

Citrus season

Every Southern Californian should have a lemon tree, and at least one orange tree. Lemons are a cook’s best friend and some citrus fruit can hold on a tree for what seems like months. Valencia oranges, for example, are the champion hangers-on, becoming sweeter and sweeter the longer they’re allowed to ripen on the tree (at least up to a point, when they begin to dry out).

Plant any citrus a little high – about an inch of the root ball should remain above ground – and be sure to use extra soil to mound up a watering basin around the plant. Trees will need to be irrigated frequently for the first year, and lightly fertilized twice a month, because that’s what they received at the growers. Later, they will need surprisingly little water and little or no fertilizing if the fallen leaves are left on the ground

Tomato time

It’s warm enough in most areas to plant the so-called main crop tomatoes – all the heirlooms, ‘Big Boys’ and beefsteaks. Close to the beach, May is a better month, unless you plant a variety that can take cooler weather such as ‘Early Girl’ or ‘Stupice,’ a Czech heirloom. When choosing any variety, look for the letters VFN, which indicate verticillium and fusarium wilt and nematode resistance, if you’ve had problems in the past.

Plant the young nursery tomatoes deep – pinch off the lowest set of leaves and plant so only the remaining leaves are above ground. Roots will form all along the buried stem, making the plant stronger and helping it forage for moisture between irrigations. Stake plants or grow them in a large cage (at least 5 feet tall). Remember, they need full sun but little fertilizer and not too much water. After the first few weeks, space irrigations as far apart as possible. Too much water or fertilizer makes for lots of growth but few tomatoes. Some coastal gardeners water once a week or less.

Eat your vegetables

Since we’re all supposed to be eating more vegetables, plant something other than tomatoes, such as beans, corn, cucumbers, leaf lettuce and other salad greens, plus melons, peppers, pumpkins, squash, sunflowers and tomatillos. And plant some basil or cilantro to go with those tomatoes.

Rampant bougainvillea

Gardeners from other idyllic climates are amazed at how well bougainvillea grows here. If the plants are doing a little too well in the garden, it’s time to take the long-handled pruning shears to them. Cut branches back quite a bit if necessary, or just a little, and they’ll quickly recover in the warming weather. Make sure you wear thick gloves because bougainvillea thorns are beyond wicked.

Bulbs bow out

Many spring bulbs have finished blooming, and though conventional advice is to leave the browning foliage, experienced gardeners have discovered it’s not necessary, except with daffodils. Let foliage completely brown on daffodils, but on other bulbs cut it off with scissors as the foliage becomes untidy. Don’t yank it off or you’ll uproot shallow bulbs and damage those that are planted deeper. There is no need to dig up and store bulbs in Southern California, but some, including most daffodils and Cape bulbs such as babiana and freesias, should be kept on the dry side in garden beds. Dig up and throw out tulips because only their leaves will return next year.

Summer flowers

Though it’s possible to plant them in May, summer’s flashy annuals and bedding plants can go in as soon as spring’s annuals have faded. Try 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-nots.

There are lots of perennials in bloom at nurseries right now and some will be in bloom this summer as well, so they’re a good bet to plant now. Look for summer-flowering agapanthus, bidens, coreopsis, daylily, gaillardia, heliotrope, lion’s tail (Leonotis), penstemon, salvia, Shasta daisy, tulbaghia, Verbena bonariensis and V. rigida, and yarrow. There are even some that bloom in fall, including asters, helianthus, Japanese anemone and Mexican marigold (Tagetes lucida).

Sow or sod lawns

Kids, dogs and lack of water can leave bald spots in lawns, and this month is the perfect time to try a patch or repair. Cut out the old sod and splice in new sod from a nursery, or cultivate the soil and sow seeds. Keep seed or sod moist until it becomes established. It’s also the ideal time to seed or sod entire lawns. If you over-seeded Bermuda lawns last fall for winter green, it’s time to start mowing lower (1/2 to 1 inch) to encourage the shorter Bermuda to green up for the summer ahead.