Wiggle Room at Planting Time

A reader wrote recently: “I have just acquired a plot in a community garden, and I am looking forward to starting a vegetable garden.” She added, “I am from England and am somewhat confused by the long growing season here in L.A. I would be grateful for any pointers you could share and any resources.”

Another reader who moved here from the East Coast was surprised to read that early spring was not the time to plant sweet peas (or any edible-podded peas for that matter).

In other parts of this country, as in much of the temperate world, spring is the time to plant everything. Certain things that prefer to grow in cooler temperatures or that abhor heat are planted in early spring--”after the last frost,” as seed packets often state.

But because so much of the Southland has no hard frost, that piece of planting advice is of no value. What gardeners need to know, be they new to gardening or relocated veterans, is whether a plant prefers to grow in warm weather or in cool.

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In the mild southern half of the state, we basically have two seasons: cool and warm.

Short-lived annual plants that bloom or produce in the cool season generally are planted in fall and winter, while those that bloom or produce in the warm season are planted in spring. (Parts of the high desert and mountains get much colder and are on their own timetable.)

Annual flowers and vegetables often are described as being “cool season” or “warm season.” In the world of vegetables, the cool-season kinds are usually leafy types such as lettuce. Or they are grown for their roots, such as carrots, or their edible flowers, such as broccoli.

Warm-season vegetables usually are grown for their fruit, with tomatoes and peppers being classic examples.

Of course, planting dates are never neat and tidy. Gardeners have discovered that they can continually grow some of these vegetables, such as beets, carrots and lettuce, if a few precautions are taken during the hottest weeks in midsummer. And they have discovered that they can extend the normal season for some vegetables in some areas.

As an example, gardeners in favored locales have found that they can plant the early varieties of tomatoes, such as ‘Early Girl,’ in late February, even though most tomato varieties are best planted in April and May. They can also plant some varieties, such as ‘Champion’ and ‘Sweet 100,’ in August, at the end of the normal season, so they will have tomatoes all winter.

Similarly, annual flowers and bedding plants are divided into cool- and warm-season categories. The cool-season crowd includes flowers native to cooler climates, such as Iceland poppies, or those from other winter-wet climates like our own, such as annual South African daisies. The warm-weather posies are typically from hot climates with summer rainfall: Mexican zinnias and marigolds, for example.

Here again, adventuresome gardeners have discovered that they can push and shove these seasonal restraints a bit. Along Orange County’s south coast, they can grow warm-season marigolds during the cool season. Cool-season sweet peas often do best when planted in late summer, for blooms by Christmas.

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The only way to really know what to plant in any given month is to get a list of planting possibilities. Plenty have been published through the years.

Theodore Payne was an early Los Angeles nurseryman with establishments at on Main Street and Los Feliz Boulevard (both long gone). The planting list he published for his flower customers is still useful today.

For spring planting, his 1929 list suggested ageratum, aster, baby’s breath, balsam, celosia, coreopsis, cosmos, gaillardia, helichrysum, marigold, the sweetly scented mignonette, portulaca, salpiglossis, salvia, scabiosa, schizanthus, sunflower, sweet William and zinnia.

Oddly, he included larkspur and linaria, two we normally

plant in the cool season. And he also listed two flowers that he said could be planted all year--bedding begonias and nasturtiums.

(If Payne’s name sounds familiar, it’s because a native plant foundation in Sun Valley is named for him--this Englishman had a passion for California wildflowers.)

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One of my favorite lists of vegetable planting times is found in the classic “Vegetables in the California Garden” by Ross Gast (Stanford University Press, 1933). In the southern half of the state, he suggests planting in April: string beans, beets, cabbages, cantaloupes, carrots, celery, chard, corn, cucumbers, eggplants, endive, melons, okra, parsley, parsnips, peas (which he said could be planted year-round), peppers, potatoes, pumpkins, radishes, squash, tomatoes, turnips and watermelons.

As can be seen in the accompanying chart of what to plant in spring, not much has changed in the last 70 or so years of Southland gardening, but there have been some additions, plants we grow now that weren’t popular then.

Various bulbs and tubers also have their season--fall-planted bulbs such as daffodils bloom in spring, but there are also bulbs to plant in late winter and early spring that bloom in summer, such as gladiolus and tuberose.

Although new bedding plants and vegetables are planted seasonally, more permanent landscape plants also have favored planting seasons. While fall is best for planting trees, shrubs and natives, winter for roses, and spring for plants that like warmth, just about anything actually can be planted in early spring--as seen in the chart--as long as the plants are watered diligently in the first few months.

Getting the Timing Right

Lists of what to plant, and when, can be found in several contemporary sources.

* Pat Welsh’s “Southern California Gardening, A Month-by-Month Guide” (Chronicle Books, $24.95) was revised this year so it is more useful than ever.

* Sunset magazine includes a Southern California checklist each month.

* Lili Singer’s “The Southern California Gardener” newsletter, which contained seasonal planting information, is about to become a bimonthly “magazinette” called “The Gardener’s Companion.” It will continue to focus on Southern California. Subscriptions are $24. Write to P.O. Box 3549, Van Nuys, CA 91407, or call (818) 780-5072.

* Robert Smaus’ “52 Weeks in the California Garden,” (Los Angeles Times, $16.95), and an annual gardening calendar, both of which have planting lists for each season or month. Call (800) 246-4042 to order either.

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What to plant in spring

Annuals and bedding plants that prefer growing in warm weather:

ageratum

argyranthemum (chrysanthemum)

amaranthus

bacopa

celosia

bedding dahlia

annual dianthus

evolvulus

gloriosa daisy

helichrysum

lobelia

marigold

million bells

nierembergia

petunia

scabiosa

summer phlox

portulaca

bedding salvia

verbena

zinnia

In the shade try:

bedding begonia

caladium

coleus

forget-me-not

mimulus

impatiens

Vegetables that need warm weather, plus a few that can grow year-round:

beans of all kinds

beet

carrot

chayote

corn

cucumber

leaf lettuce

melon

New Zealand spinach

onion (from small bulbs called “sets”)

pepper

pumpkin

radish

squash

sunflower

Swiss chard

tomato

watermelon

Bulbs and tubers that bloom in summer:

begonia

caladium

canna

dahlia

gladiolus

gloriosa lily

Peruvian daffodil

tuberose

tigridia

Subtropical trees, shrubs and vines, which include:

citrus

hibiscus

banana

ginger

bougainvillea.

From nursery containers:

roses

deciduous fruit trees

What not to plant now:

California natives, which are very sensitive to summer watering.