You don’t have to be a green thumb or a gourmet cook to want an herb garden. Even if you don’t use them in the kitchen, just their lovely aroma wafting in the warm summer air is a delight. And if you do use them in your cooking — oh, what a difference fresh herbs make!
If, like lots of people, you’ve struggled to grow herbs successfully here in middle Tennessee, don’t despair. Growing herbs in our part of the world can be done with great success. You just have to give the tasty little fellers the conditions they want.
Generalizing hugely, there are two main categories of herbs: perennial ‘permanent’ herbs like thyme and rosemary, and annual/biennial herbs like basil and parsley. Perennial herbs are the ones that usually give folks trouble.
Most of the perennial culinary herbs we love are native to Europe, particularly the sun-drenched lands around the Mediterranean. They come from a climate that’s warm and dry in summer, cool and dry in winter, with rains spring and fall. Point of fact, the Mediterranean herbs like thyme, rosemary, and lavender are technically subshrubs that naturally prefer rather poor rocky soil. What this tells us gardeners is that Mediterranean herbs are built for full sun, great drainage and almost no fertilizer.
Of course, in Nashville we specialize in hot, steamy summers and — more importantly for perennial herbs — cold, wet, root-rotting winters, along with (usually) moist springs and dry autumns. And then there’s our middle Tennessee soil. Don’t know about you, but at my house a good rain makes walking in the garden a slog, and dry weather has the soil cracking like concrete. Unless you’re one of the lucky few who live on deep loose river bottom loam, you don’t have the kind of soil that any self-respecting Mediterranean type herb would regard as “well-drained”.
So how can you keep your herbs happy and productive?
Simply do three things: first, choose a sunny site for your herb bed, one that gets at least the afternoon’s full sun; second, add lots of drainage to that bed; and third, choose the right variety of plant. The last two aims are easy to achieve. (If you live in the deep woods with no real sun, well, a successful herb garden might not be in your future. Sorry.) At Moore & Moore we offer varieties that are known to do well in our area, so you can be sure you’re making a good choice whatever you buy. And for drainage, get a product called Perma Till®, and get some gypsum if you have particularly heavy clay. Perma Till (also called VoleBloc, because it keeps root-chewing voles away from plants) is an expanded slate material that you dig in to the soil where you’re planting herbs. It really makes a big difference in drainage, and herbs LOVE it. Digging in gypsum helps bust up tight clay soils naturally —woody herbs such as rosemary and thyme really appreciate it.
An established rosemary blooming in a Nashville garden April 3, 2013.
The easier-to-grow annual and biennial herbs prefer full sun, too, but they like richer, moist soil. Basil, parsley, fennel and so forth typically are happy in our native soils as long as it’s not constantly boggy or too dry. If you live on a hillside of chert, the good news is these herbs are easy to grow in big pots. Wherever you grow herbs, don’t feed them much. The reason for this is that less soil fertility promotes concentrated quantities of the volatile oils that you grow herbs for. More fertilizer = less potent herbs.
Here’s how to have some fun with specific herbs:
Basil – Keeping flower heads pinched off promotes more leaf growth. But if you want to support your local bee population, let them bloom. Bees adore basil flowers. I adore pesto and helping out our bee friends, so I plant lots of lettuce leaf basil (a 50-foot row!) to ensure plenty of leaves for pesto and blooms for bees. For more basil tips, see our earlier blog posts on basil.
Chives – This little onion likes fairly rich moist soil, and benefits from more fertilizer than most herbs.Clumps increase over time, and need to be divided every three or four years, an easy task. Don’t cut too much foliage the first year after planting – it takes about one full growing season for a clump to really get its groove on. After that, you can cut half the foliage off at a shot. Just give it time to recover before you raid it again.
Cilantro – It’s always struck me as odd that salsa was ever invented, since it pairs tomatoes (hot weather crop) with cilantro (cool weather herb). You can’t grow them simultaneously, not around here anyway. Cilantro does great in the spring and then rapidly gives up the ghost when hot weather arrives, so plant it early and keep it moist to encourage rampant growth. Cut and freeze or dry it when it’s big, bodacious and tasty, usually by May. If you let some go to seed cilantro often self-sows and provides volunteers the next spring, unless you collect the seeds for use as coriander. Coriander and cilantro are the same plant.
Fennel – Easy to grow. I usually have this in a combo pot on my patio because I find its feathery foliage pleasing to look at and Black Swallowtail caterpillars find the foliage delectable eating. Black Swallowtails are beautiful butterflies and I like watching the caterpillars grow, pupate and turn into those gorgeous fluttering creatures. Great fun to share with your kids or grandkids.
Lavender – Not a culinary herb, but you grow it like one. Sun and great drainage are key. And don’t overcrowd the plants, as they get moldy in humid weather if they’re jammed together. Two great varieties I’ve had luck with are ‘Grosso’, with striking, very silvery foliage, and ‘Provence’, an especially aromatic type that was originally developed for the perfume trade.
Mint and Oregano – These plants are best grown in containers because they’re aggressive growers that easily elbow aside any other more politely restrained herbs in their vicinity. Believe me, one big pot of oregano will produce more than you’ll ever use. Same with mint. If you’re into mint juleps, by the way, spearmint is the mint of choice for that libation. There’s a really fine variety called ‘Kentucky Colonel’ that’s often grown just for that purpose.
Parsley – Parsley is a biennial, meaning it’ll live through the winter and grow like crazy the next spring. Then it sends up a flower stalk, which signals the end of its life cycle. The flat-leaved ‘Italian’ type is typically used in cooking, while the curly kind is usually used these days as a garnish to gussy up a T-bone. That parsley garnish didn’t start out as an aesthetic touch – in olden, pre-Altoids times it was eaten as a breath freshener at the end of the meal. Parsley is a terrific natural mouth cleanser.
Rosemary – Nothing makes me hungrier, even if I’ve just eaten, than brushing up against a rosemary plant. There’s something about that aroma that is just mesmerizing. Rosemary is a good looking, garden-worthy plant, too, with blue flowers in late winter and early spring. Good drainage is appreciated, and enough room, as they get big. ‘Arp’ is a standby in Tennessee, as it’s pretty bullet-proof in our climate. Another cool variety that does well here is ‘Barbecue’, which grows tall straight wands that make wonderfully aromatic skewers for shish kabobs and other grilled delights.
Sage – Sage (Salvia officianalis) wants the same culture as rosemary and lavender. It can get to be a fairly sizable shrub, and the leaves are so potent that you probably only need one. ‘Berggarten’ is particularly successful in our area, and I’ve also had good luck with Purple Sage in containers.
Tarragon – A wonderful herb (Chicken Tarragon – yum!), but somewhat tricksy to grow. Terrific drainage is essential, and a sheltered sunny position. French tarragon is not a particularly long-lived plant even when well grown in my experience, so plan on replacing it every few years. Tarragon is not a particularly vigorous plant, so be sure to give it its own space and make sure it’s not crowded out. I grow it in a container.
Lemon Thyme ‘Doone Valley’ in a Green Hills garden, happily occupying gravelly soil between a boulder and a flagstone path.
Thyme – There are lots of kinds of thyme on the market. The sort you buy in a jar at the grocery store are leaves from Thymus vulgaris, often sold as either English or French thyme. Lemon thyme and its many variations are wonderful in cooking too, while the creeping thyme that does so well between flagstones can be either of two species, T. serpyllum and T. praecox. Then there’s Mother-of-Thyme, Woolly Thyme, Caraway Thyme and others species beyond that, and taxonomists are busy wrangling over correct nomenclature. Gives them something to do, I guess. Whatever botanical name they end up with, all thymes want sun and really great drainage. Thyme commonly rots out in one winter in heavy, un-amended soil – I see it all the time.
If you decide to get serious about herbs, the Herb Society of Nashville is a terrific resource. Check them out at www.herbsocietynashville.org.
Posted on 04/07/2013 at 12:00:00 AM