If you want to know anything about growing herbs in the Midwest, talk with Mary Hammer. She’s a member of the St. Louis Herb Society and chairman of the group’s upcoming Herb Sale at the Missouri Botanical Garden April 27-29. The effervescent Mary can fill a book just off the top of her head when she taps into her knowledge of how to grow, use and harvest these stars of the garden, kitchen and even the medicine cabinet.

Recently, she shared with us what she calls her “baker’s dozen” top culinary herbs: Basil (annual); salad burnet (perennial); onion chives (perennial); dill (annual); French tarragon (perennial); lavender (perennial); lemon verbena (perennial); spearmint mint (perennial); Italian flat leaf parsley (biennial); oregano (perennial); rosemary (tender perennial); thyme (perennial); sage (perennial).

While cilantro/coriander may be the herb of the year selected by the International Herb Association, it is hard to grow in St. Louis, Mary says. “It doesn’t like to be cooler than 75 degrees and doesn’t like to be hotter than 80. Otherwise, it goes to seed. If you like cilantro, the easiest thing is to buy it in the grocery store.”

For the best results, perennial herbs can be planted the last week in April, but annual herbs should not be planted until the second week in May. “They don’t like to be wet or cold,” she notes.

Almost all herbs can be successfully grown in pots, Mary says. The one exception is basil. “The plants generally get so big; they do best in the ground.” But she cautions against putting a number of herbs in the same pot. “That generally doesn’t give any of the plants enough space to grow,” she points out. “It’s best to give each herb its own pot and then group the pots together for a nicer display.”

Mint, she emphasizes, should always be grown in a large pot because its spreading, invasive nature can overwhelm other garden plants.

“The best time to harvest any herb is before it blooms,” Mary advises. “Once the energy of the plant has to go for flowers, the leaves tend to get a little bitter. The best time of day to harvest is in the morning after the dew has dried. Dry the herbs between paper towels and make sure to label them so when they are dried, you know what plant those leaves are from. Store the leaves whole in labeled glass jars; don’t crumple them up until you are ready to use them. Keep the jars in a dark place.”

How long can you keep dried herbs? “Rub them in your hand; you should still get a strong aroma. You can keep them as long as they give you some taste,” Mary says.

For additional fun facts from Mary Hammer regarding growing herbs, visit the St. Louis Homes & Lifestyles website.  

More extensive information on growing herbs and great recipes are available on the St. Louis Herb Society website at www.stlouisherbsociety.org. There is also a list of the 120 new and hard-to-find varieties that will be available at the group’s herb sale at the Missouri Botanical Garden’s Orthwein Floral Display Hall in the Ridgway Visitor Center. Herb sale hours are April 27, 5-8 p.m. for Missouri Botanical Garden members only. April 28, 9 a.m. to 5 p.m. for everyone, and on April 29, 9 a.m. to noon only if there are plants remaining. 

Mary Hammer is chairman of the St. Louis Herb Society’s Herb Sale at the Missouri Botanical Garden April 27-29. Here are some additional notes on growing what she considers the baker’s dozen top culinary herbs. For more information on the sale and a list of the 120 varieties that will be available, visit www.stlouisherbsociety.org.

Basil: Lush green ‘Genovese’ basil is the all-time favorite but for fun try ‘Amethyst’ or ‘Purple Ruffles.’ A new favorite ‘Mammoth’ or ‘Lettuce Leaf’ has huge leaves and a strong flavor. It comes in both green and red/purple leaved versions. Greek columnar basil grows tall and slender and has a lemony flavor. African blue basil is an ornamental basil that is a bee magnate. It can get huge. Plant it in an out-of-way-place in your vegetable garden to attract pollinators. While basil can be grown in containers, it gets quite large and does best in the ground. Cut off the flowers or the taste of the leaves can turn bitter.

Salad Burnet: A tidy perennial that doesn’t get out of control. It has a wonderful cucumber flavor and is great to flavor vinegars and in salad dressing. It is one of the first things up in the spring.

Chives: Plant onion chives; the chives with the purple flowers. Don’t grow garlic chives with white flowers; they are extremely invasive. The purple/lavender flowers are edible. Once they have flowered, cut chives back to about 4 inches; they will come back nice and full and flower a second time.

Dill: It is so easy to grow. I let mine flower and go to seed. It dies back in the summer heat but will re-seed itself and come back. I use dill in so many things. My grandson loves dill pickles so I have to grow a lot of dill.

French Tarragon: When the weather gets hot, it needs some afternoon shade and it needs very good drainage. If it is not happy, it croaks, but if you find the right spot, it will come back year after year. Finding that spot can be a bit tricky. When you are buying tarragon, pull off a leaf and make sure it smells like licorice. That is the way you know you are getting French tarragon.

Lavendar: It is the trickiest herb to grow. It will not survive if it has wet feet. You have to amend the soil and it has to have full sun and plenty of space for air circulation. Growing it in a raised bed is best. Don’t use organic mulch. It prefers no mulch or gravel. ‘Munstead’ or ‘Dilly Dilly,’ a smaller lavender, will do well in a pot without a saucer. Never use moisture retaining potting soil. ‘Angustafolia’ has the sweetest flavor for culinary use.

Lemon Verbena: Excellent for summer ice teas and makes a wonderful simple syrup for sorbet. Mine seems to do best if I dig it up in the fall, cut it back and put it in a pot. It has a lemon vanilla sweetness.

Mint: For culinary use, the best one is spearmint. It is totally hardy and should be grown in a nice, big container.

Italian Flat-Leaf Parsley: This has the best flavor of any parsley. It is very suitable for a container. It is a biennial but when it comes back for the second year, it goes straight to making flowers and the stems are thicker so it is best to treat it as an annual. It is one of the herbs you can use in almost any cooking.

Oregano: It will spread so it is best to keep it in a designated area and it will do well in a large pot. There are so many different kinds. If you are doing any Italian cooking, you have to have oregano. Keep the flowers cut and in late summer cut the plant way back. ‘Kent Beauty’ is a wonderful ornamental oregano with beautiful flowers. You can put it in a good-sized pot with rosemary. If you want a slightly sweeter, milder flavor than oregano, try growing marjoram. It’s an annual here and is beautiful in a container. The flowers will dry so you can cut them off and save them. They won’t fall off the stems.

Rosemary: It’s a perennial but it is not reliable. It’s great for containers and needs very little water. ‘Barbeque’ rosemary is tall and you can plant other things around the base. ‘Blue Rain’ is trailing and lovely in a pot. Rosemary is wonderful on roasted vegetables.

Thyme: It’s a necessity for cooking. I’m always running outside and cutting a few sprigs. French or English thyme are best for cooking. Lemon thyme is nice for a citrus flavor. When thyme gets leggy, cut it way back.

Sage: Garden sage is best for cooking. For fall color you can’t beat  ornamental pineapple sage (spikes of red flowers) or Mexican bush sage (spikes of purple flowers). Sage doesn’t need lots of water, so you don’t need to fuss with it.