By Dan Gill
LSU AgCenter Horticulturist
(11/24/17) Louisiana gardeners can successfully grow a wide variety of culinary herbs. When selecting which herbs you want to grow in your garden, consider what you commonly cook with. Look at the dried herbs are in your kitchen cabinet, and start growing them.
Now is a great time to plant many of the hardy herbs we love to cook with. These herbs establish reliably when planted during the mild weather we have this time of the year. Winter cold will not hurt hardy herbs, and they grow vigorously during mild weather. Fall-planted hardy herbs are far more productive when compared to planting them in spring.
For growing purposes in Louisiana, we can group herbs into cool-season annuals, warm-season annuals and perennials. Annuals live for one season and then die. Cool-season annuals grow from October to May, and warm-season annuals grow from April to November. Perennial herbs live for several years. This time of year, we can plant cool-season annual herbs and hardy perennial herbs.
Cool-season annuals
Cool-season annual herbs are not bothered by winter freezes and actually prefer to grow in the cool to mild days and chilly to cold nights we have here during the cool season. Transplants should be planted from October through March. Although I recommend fall planting, you can expect to get a decent harvest when cool-season annual herb transplants are put out in spring — plant the largest transplants you can find. Still, fall planting will far and away produce the largest and longest harvest.
Herbs we grow as cool-season annuals include parsley, cilantro/coriander, celery, dill, chicory, fennel, borage, arugula and chervil.
Perennial herbs
Perennial herbs are also generally not bothered by winter cold. Most of the perennial herbs are best planted from September through April using transplants available at local nurseries. Fall planting is particularly advantageous because it allows these herbs to establish during the less-stressful cool season.
Some of the perennial herbs that do well here and can be planted now are mints, lemon balm, rosemary, burnet, sorrel, catmint, garlic chives, oregano, thyme, sage, lavender, monarda, catnip, anise hyssop, mountain mint, French bay, pineapple sage and rue. A few perennial herbs that like the heat and would rather be planted in spring include Mexican tarragon, lemon verbena, lemon grass and society garlic.
A few perennial herbs are especially sensitive to heat, so they’re always best planted in fall. Thyme, sage, catnip and lavender fall into this category. Although they generally thrive in the garden during the cool season from October to early May, they struggle during our hot, humid summers. By planting in fall, these herbs will be better established and more likely to make it through the summer than when they are planted in spring.
Because they are prone to root rot when weather is hot, thyme, sage, catnip and lavender require excellent drainage to survive the summer. They may be more successful when grown in containers and placed in a location that gets some shade in the summer afternoon.
Several perennial herbs almost never survive our summers and are best grown here as cool-season annuals. Transplants are planted in fall, grow vigorously over winter and produce harvests into spring. As the weather gets hot, they typically lose vigor and die in early to midsummer. Perennial herbs in this category include French tarragon, feverfew and chamomile.
Most herbs require direct sun at least four to six hours a day and excellent drainage. Raised beds are a good idea for many herbs because of our abundant yearly rainfall. Herbs should be fertilized moderately to avoid stimulating lush growth that will be less flavorful. Generally, fertilize herbs with the same products you use for your other plants but at about half the amount.
Locate your culinary herb-growing area as close to the kitchen as possible so they are convenient to use while you are cooking. If you have to walk all the way across the yard to harvest them, they’ll likely be underused, and the plants will become overgrown and wasted.
Herbs grow very well in containers. As an alternative to an in-ground garden near your kitchen, you can locate pots of herbs on a back porch, deck or patio to be convenient. And because you don’t generally need more than one to a few plants of each type of herb, a nice container herb garden does not have to include a huge number of pots.
Although you can grow herbs as ornamentals for their beauty and appearance, and some people seem to just collect and grow herbs for the sake of growing them, it’s important to remember that above all, these are meant to be useful plants. The culinary herbs are intended to be harvested regularly to flavor and enrich your home cooking. You won’t hurt them by harvesting — that’s what they are there for.
Don’t wait for spring to start a new herb garden or add to an existing one. Plant hardy herbs now. When fellow gardeners are purchasing and planting herbs next spring, you will be enjoying bountiful harvests from well-established, vigorously growing plants.
Parsley can be grown as a cool-season annual in Louisiana. Photo by Kiki Fontenot/LSU AgCenter
Rosemary is a perennial herb in Louisiana that can last for years in a garden. Photo by Kiki Fontenot/LSU AgCenter
Oregano is a perennial herb that does well in Louisiana and can be planted now. Photo by Kiki Fontenot/LSU AgCenter