Please take part in our Reader Survey!
The Lazy Gardener’s Guide to Winter
story and photography by Leslie H. Cummins
Face it—it is the heat!
Our gardens on the northshore of Lake Pontchartrain (Hardiness Zone 8b) have more in common with gardens in Tampa and Brownsville, Texas than with those in Alexandria and Shreveport. While we share the same hardiness zone number as areas of California and Oregon, our Zone 8 conditions vary dramatically from theirs. The northshore’s long, hot and humid summers, with nighttime temperatures that never drop more than a few degrees from our daytime highs, provide growing conditions that many plants find daunting. Our mild winters fail to provide the continuous chill needed to coax many shrubs and trees out of dormancy—rendering them, in effect, dead.
I have learned to prepare my garden for the worst weather of the year. Not the winter blizzards and snows of my Minnesota friends, but the unbearable heat and humidity of coastal summers. When the solstice occurs on June 21, the days are at their longest, and the worst of the heat is yet to come. It is time to mulch heavily, set the sprinklers, and head inside to redecorate the kitchen. It’s not until the first cool nights appear, sometime between September 15 and October 15, that I reclaim my yard.
Winter is the best time to garden! The mornings are cool, there are fewer pests—for humans as well as gardens—and many plants begin a second growth spurt and flowering. This is the season to plant new shrubs and trees, and to fill those spaces left by spring ephemerals, such as lilies and daffodils, with annuals that will light up the landscape all season. Annie Coco, extension agent with the LSU Ag Center, is an avid winter gardener. “Of all the plants that thrive during the winter months, some of the most beautiful happen to be edible,” she says. “Lettuces, cabbages, and kale offer seasonal color, and many herbs are beautiful and fragrant.”
Microclimates
While northshore gardens do occasionally experience temperatures below 32 degrees, my yard, which is only about a mile from the lake, never stays below freezing for very long. Even within the confines of my property line, there are microclimates that have not been below freezing in four years. The brick-facing southwestern exposure of my house, with a broad overhang and a wide stone walkway, has fostered freeze-tender impatiens through the darkest days of January and February. I use the retained heat of this wall and walkway to overwinter many tender plants and to trick one difficult biennial into blooming a year early. (See sidebar.) Along this wall I string two or three sets of cheap white (not LED) Christmas lights. All my tender potted plants are set along this wall, the seedlings among them, and they are covered with blankets and towels any time a freeze threatens. Each morning, they are uncovered and the Christmas lights are turned off. Since all the plants are in one place, this takes only a few minutes, as does watering and checking for pests. Knowing and understanding the microclimatic conditions in your yard will help you determine the things you will be able to grow.
The right plant in
the right place
There are two ways to do anything: the easy way and the right way. Gardening is the only occupation I can think of where the easy way is the right way. Putting the right plant in the right place is the most important thing a gardener can do. When a plant is happy in its location, it will settle into a contented process of growth and rest, remaining relatively pest free. When a plant is stressed, however, it releases chemicals that are an attractant to garden pests—making the plant a constant source of aggravation to the gardener, who has to spray and prune constantly to keep the bugs at bay. The constraints of winter gardening in our coastal south—low light conditions, cool temperatures and periods of heavy rain—may limit the palate of plants available, but the rule holds true: Put the right plant in the right place and the garden will thrive on neglect.
Sunlight
Six hours of mid-summer sunlight is to a plant what filet mignon is to a human: pure fuel. To all plants, light is fuel; however, in the same way that the steak that I love makes my daughter sick, some plants don’t tolerate full sun, and will thrive on low-light conditions. Winter provides challenges to all three characteristics of light: quality, intensity and duration. One of the first indications of fall is the color shift in the sunlight as the sun cycles lower in the sky. This shift in light quality indicates that there is less of the blue wavelengths (contributes to leaf growth) and red wavelengths (promotes flowering) and more of the yellow-green (which is reflected from the leaf surface and not used by plants). Second, our Zone 8 gardens are not quite the sub-tropical gardens of Zones 10 and 11, and we do experience a lessening of light intensity during the winter months. Equatorial gardens enjoy almost identical measurements of light during the winter as during the summer. Lastly, it simply does not stay light as long during the winter as during the summer. On June 22 of this year, there were 14 hours and 5 minutes of daylight; on December 22, only 10 hours and 8 minutes. These three changes in light conditions cause most plants to become less active during the winter months, and in some species, promote dormancy.
Temperature
Red and green lettuces, which struggle during other seasons, thrive on the cool nighttime temperatures of fall and winter. Our uncertain weather, where it is near freezing one day, and soaring into the eighties two days later, provides the biggest challenge to winter-grown plants. Research indicates that most plants grow at their best when there is a 10 to 16 degree temperature difference between the maximum daytime temperature and the minimum nighttime temperature. This cooling does not occur during the sultry summer months, but is common in the fall and winter. This effect allows the gardener to trick some biennials into blooming within one calendar year. (See sidebar.)
Water
An adjunct to the temperature issue, water is necessary in many biochemical reactions in the plant, including respiration, the process by which leaves give off oxygen and water vapor. Everyone from Louisiana knows that hot air holds more water vapor than cold air. During the hot, humid nights of summer, plants simply cannot “breathe.” The cooler, less humid nights during the fall and winter months allow plants to photosynthesize fuel during the day, and to respire at night, releasing waste products. This combination provides the maximum conditions for healthy, happy plants.
Annie’s Picks
Most gardeners don’t care that there are a lot of scientific reasons why plants grow well in the fall and winter in our area. The most important reason for gardening this time of year is that it’s fun! Here is Annie Coco’s list of plants—vegetables, herbs and flowers—that won’t grow at other times of the year. Try them now that the days are cooler.
Fruits and vegetables. “Strawberries grow best when planted in November,” Annie says. “Growers in Tangipahoa and Washington parishes are putting in their crops now, so home growers will be able to find plants at their local feed and seed shops.” She recommends planting them in beds in the ground, but says they can also be grown in hanging baskets and pots. Leafy vegetables, including collards, kale, Swiss chard, spinach, turnips, mustard and Chinese cabbages, can be planted now and harvested until the weather turns hot. “‘Bright Lights’ Swiss chard has beautiful, colorful stems and is a wonderful plant in the landscape,” she notes.
Root vegetables should be planted now, and these are beautiful plants as well; beets, turnips, carrots and radishes can be grown from seed. “They should be started where you want them to grow,” says Annie. “They will not transplant without damage to the roots, which causes malformation of the vegetable.” Lettuces grow well under any normal garden conditions. Black Seeded Simpson is the most heat tolerant, and can be transplanted out in September and October. Other varieties such as romaines and kos should be transplanted now, when the nights are cooler. Harvest lettuces by taking only the outside leaves and allowing the crown of the plant to grow back. Plan on transplanting several lettuce crops throughout the winter season, stopping only when daytime temperatures are expected to rise above 80 degrees.
“All cole crops do well during the winter,” Annie offers. “These include cabbage, broccoli, broccolini, cauliflower and Brussels sprouts. The Brussels sprouts are most prone to bolting during warm spells, so just pinch out the top to force the plant to put energy into making the sprouts. Somehow, they are never very big, and they don’t form firm, compact heads, but they will taste delicious.”
Herbs. Annie suggests dill, parsley, cilantro, oregano, and fennel, bulbing and herbaceous. “Basil gives up at the first threat of cold,” she says. “Grow rosemary instead.” She recommends a well-drained, sunny location for all herbs. Most herbs will grow in pots, and she recommends adding builder’s sand to the mix for rosemary because “it doesn’t like wet feet during hurricane season.”
Flowers. Violas, pansies and snapdragons are fall standbys in northshore gardens. Plant them during the fall for riots of early spring color. Sweet alyssum can be seeded into the garden any time from September through January for sweet fragrance the following the spring. The tiny plants come up and grow right through the coldest days of the year.
Take a few moments twice a month during November and December to plant sweet pea seeds. These vivacious bundles of pastel colors will last for a week in a vase. I pick a sunny spot with a trellis or fence for them to climb, and seed them in every other week until Christmas. They will come up, but will remain only few inches tall until about the middle of February, when they will quickly cover the trellis. Keep the flowers cut, and you will harvest bouquets until May.
The Most Glorious Garden Season
When the early morning light slants through the few remaining trees bordering my yard, it lights first the eaves of the house and the hanging baskets of strawberries. I sip my first cup of coffee and watch the steam rise into the cool fall air. Gardeners in Vermont and Minnesota have put their gardens to bed, and their roses sleep now under blankets of snow. My roses have just started their final bloom of the season, and will provide a blossom for my breakfast tray until New Year’s Day. I put down my coffee cup and pull on my gardening gloves. In my Madisonville garden, winter is the most glorious season!
A Tightwad Tip
Foxgloves are my favorite spring flowering plant, although many gardeners on the northshore have told me that they are never successful with it in their gardens. It is an expensive plant to buy in ready-to-flower flats, however, because it is a biennial—not an annual, which has to be started afresh each year, and not a perennial, which can be planted out once and will continue to live in that place for many years. A biennial is a plant that grows from seed in the spring but has to go through a winter to come into bloom the following, or second year.
Luckily, these cheerful bloomers are easy to start from seed, inside, in a cool but bright window. I start the seed in the fall in 4x4 pots because I don’t want to move them to bigger containers until the following spring. When they come up, I thin the seedlings to only the strongest contender per pot, and as soon as they have their second set of leaves, they go outside in a shady, cool spot near my water spigot, where they are watered every morning and evening, if the daytime temperature has been over 85 degrees. On the first frosty days of November, they are placed against that southwest wall, along the stone walkway, watered only when they are dry, or about once a week if there is no rain.
The foxgloves thrive during the cool weather, though they don’t grow very much, if at all. But early in spring, even before I have noticed any difference in the length of the days or a rise in temperature, they begin a growth spurt. It seems as if every day brings a new set of leaves. At this point, they have been tricked into thinking that they are two years old, and they are ready to bloom. Plant them out into the garden in a spot that will have some sun in spring, and more shade in summer (near, but not under a deciduous tree is ideal) and they will send up blooms in about two months. The flowers will produce seed, so leave some on the plants to provide next year’s crop and then yank the plants when they start to look pale. The first wet days of June will turn them to mush, unless they are planted into raised beds with superb drainage. Even there, I have never had them set seed for me in the garden. I believe that our fall days are just too hot for germination. They will, perhaps, come up in the spring, but will take two years to bloom in the garden.
