Fall is a great time to plant herbs in the Houston area. Cool season annuals to be planted or started from seed in October or November include: dill, parsley, fennel, borage, coriander / cilantro, calendula and nasturtium. These herbs will flourish now through spring with only nasturtiums affected by a hard freeze. They will flower and set seed next spring, then die back once the weather heats up in May. At that time you can plant basil which thrives in warm weather.
Perennial herbs to transplant in October or November from 4” or larger pots include: rosemary, lavender, catnip, culinary sage, pineapple sage, ornamental salvias, bay trees, oregano, Mexican mint marigold, lemon balm, lemongrass, lemon verbena and mints. There is nothing better than your own fresh picked bay leaves and oregano added to stew or spaghetti sauce – remember to remove bay leaves before serving.
Rosemary does well planted in the fall and rewards you with tiny blue flowers in early spring. Remember that “a dry rosemary is a dead rosemary” so don’t let it go for more than a day or two in overly dry soil. Cut back or harvest up to 1/3 of the mature plant to maintain a bushy habit. Rosemary has very shallow roots, so it is not easy to transplant once it becomes a large plant.
Plant any variety of lavender you would like to grow in October or November – pick the fragrance you prefer by brushing a few leaves to release their fragrance. Many varieties of lavender will not fare well in our Texas summer heat but I’ve had success with “fern leaf lavender” and “sweet lavender”. The best way to insure lavender won’t rot from excess moisture is give it good drainage by adding sand or pea gravel to the soil or potting mix. Mulch with one inch of pea gravel or sharp sand to increase the amount of blooms in spring.
To successfully grow catnip I recommend placing a wire basket over the heart of your plant. By having a barrier over the base of the catnip you will protect the herb from cats who love to nibble the leaves and roll on it. Plant catnip near a window for excellent “cat watching”.
Pineapple salvia has small red blooms from summer through fall and an excellent fragrance year round. Use it with fruit salad by adding a few fresh sprigs to a bowl of freshly chopped fruit. After a few hours in the refrigerator the fruit will have a lovely pineapple-herby fragrance. I also grow ornamental salvias: Indigo spires, Mexican bush sage and black & blue salvia. The black and blue salvia is by far the easiest to grow given at least 4 hours sun. It spreads by underground runners and can take over your garden, so be ready to give away extra plants to all your friends.
I love my beautiful large bay trees and encourage you to grow one. They are slow growing but make a lovely specimen tree for a full sun area of your garden. I’ve noticed the leaves attract the beneficial green lacewings to my garden. If you discover scale or a black sooty mold substance on the leaves it means you are growing it in too much shade.
Oregano is easy to grow, forming large clumps that need to be divided every 3 years or so. I prefer Italian oregano for its flavor in cooking. Another great culinary herb, Mexican mint marigold is called “Texas tarragon”. Clip and use it year round but stop cutting it by the end of June for delightful yellow blossoms in the fall.
Lemongrass and lemon verbena are favorites for refreshing herbal teas. Lemon verbena becomes a small shrub with lots of slender leaves to harvest and dry. When the weather turns cold, the leaves usually drop leaving bare branches through winter. Be sure to mulch, water and cover before a freeze to protect this tender perennial shrub. It may take a while to bud back out in spring, so don’t give up hope and think it is dead. Water and wait -- it will branch back out at which time you can prune to shape it up a bit. Lemongrass will bloom with a large plume in late fall if you haven’t cut it back in a few months. It will die back to the ground in freezing weather but recover from the roots once spring is here.
Lemon balm and all the various mints will thrive in fall weather. Protect them from a hard freeze and they will return from the roots in spring. Meanwhile you can clip and use them fresh or dried for a delightful cup of herbal tea on a cold winter day.
Water the ground well to protect your herbs before a hard freeze. You should have already mulched everything in your garden before winter sets in. Use freeze cloth or sheets to cover herbs, securing the edges with rocks or bricks to make sure they don’t blow off during the night. Do not immediately water plants with frost or frozen foliage once the weather warms as this can cause more damage than the freeze itself.
The most important advice I can give you for successfully growing herbs during the winter is to remember to water well at least once or twice a week if we haven’t had sufficient rainfall. Many herbs that suffer and die over the winter do so from a lack of water, not the cold weather.
Submitted by Susan Wood
The Herb Society of America - South Texas Unit