• Design Plans: Grow These 10 Herbs for Drought and Humidity
Dear Herb Companion,
My yard is definitely a challenge, and I am clueless about what to plant and where. I have a lot of rocks and red clay, so plants do not do well along the edges of my house. I have a few herbs in a little bed under a bay window that gets mostly sun. I would like to learn how to grow all types of culinary, medicinal and cosmetic herbs. I live in central Alabama.
—Jessica Fields, Sylacauga, Alabama
See pictures of Jessica Fields' garden in central Alabama.
Every garden space brings its own set of challenges. It’s true that the Deep South—with its heat, humidity and often heavy clay soils—offers particular challenges to herb gardeners. But, as in many other areas of the country, time and sweat will improve both your soil and your knowledge. Digging in and learning how to plant and maintain beautiful gardens in your yard will also bring with it an acceptance that there are some things you can’t change.
From the photos you sent, it looks like you have a lovely setting for a mobile home that you’ve expanded and built decks onto. Perennial garden beds will give your home a feeling of permanence and anchorage, beauty and bounty, as well as a steady harvest of materials to suit your interests.
You live in Zone 7b or 8a, which allows you to grow some herbs outdoors that Northern gardeners can only dream about. I’ll bet in a drive around your community you would see large shrubs of rosemary in the landscapes, tree-sized bay laurel plants and many other herbs thriving in gardens. We’ve redesigned your sunny bay-window garden for a variety of herbs that can take advantage of your mild winters and long growing season and survive the summer heat, including a variety of traditional culinary, medicinal and cosmetic herbs.
Track Your Sun Exposure
Elsewhere in your yard, look carefully at the sun exposure you get, and for how long, in any of the areas you want to plant. Evaluate this over the course of a day and, for that matter, the seasons, because the sun exposure can change as trees leaf out or go dormant and shadows change as the sun shifts its path across the sky.
Full sun means at least six to eight hours a day, but in the South, it’s helpful to think about the late-afternoon summer heat, especially if it’s also being reflected off the light-colored siding of your home. While many herbs require full sun to thrive, like many other plants and even people they might appreciate some shade in the hottest time of day. So an open eastern or northern exposure that gets enough morning and early-afternoon light can be suitable for growing many herbs.
In other areas that get only dappled light for the greater part of the day because of the trees, be grateful for the shade and choose herbs and other plants that are suitable for shade or partial shade, as well as plants that you see can do well in your community, rather than struggle to grow many culinary herbs that may survive but not thrive. Either that, or trim back some of the greenery to let more light in, if you can.
Amend Soil to Drain Well
Clay is often fairly high in minerals and other nutrients, compared to sandy soils, but it can pack down and stay soggy and heavy, almost anaerobic, meaning not enough air gets down to the roots. Those conditions spell almost certain death, at least in the long run, for almost all Mediterranean herbs. They demand soil that drains well, so improving the drainage in clay soil is critical for growing herbs successfully in your climate. Heavy soil can be improved by digging in sand, but clay plus sand can equal a soil texture that resembles brick—so be sure to add lots of organic matter to your soil whenever you add sand. That’s where compost comes in, and it will also feed those busy worms and microorganisms that live in the soil and do their part. This will help balance out extremes of pH, improve the soil dramatically over time and give your herbs a better medium to sink their roots into.
The more decayed organic material you add to your soil, the better, and that will also have the effect of raising the height of that little bed under the bay window, which always improves drainage. You can dig about 30 percent to 50 percent compost, sand and other amendments in the top foot or so of your native soil. Prep work always pays off in healthier, more robust garden plants, but don’t think you’re done, as improving your soil is an ongoing process.
The Mediterranean, where most of these herbs originated, has rocky soil. So you don’t have to worry too much about the rocks in your soil, as long as they don’t form a solid layer that impedes drainage. I usually pull rocks out of garden beds, as they annoy me, and I try to find other uses for them. Starting with small transplants makes planting easier in rocky soil, for the patient gardener.
The often wet conditions and high humidity levels are another challenging factor in growing the many drought-tolerant herbs that you want. You’ve raised your bed and improved your soil so that it drains faster. That helps a lot, but you also want to keep the rainy season in mind when you plant.
Spacing the herbs out a bit will let air circulate around and through them as they grow. Avoid that cottage-garden look where the plants all grow together and lean into each other so that the garden looks like a wonderful jumble of nonstop plants. You’re going for a different look. Let each plant have its airy space. This will help you avoid many of the powdery mildew, root rot and other fungal diseases that are prevalent in moist conditions.
Mulching the bed after you plant is an important step to prevent water from splashing up and collecting onto the lower leaves—as well as the other myriad ways that mulch helps, such as weed control, preventing the top layer of the soil from crusting over, and so on. Look around for suitable local materials to use, and consider light-colored gravel mulch (or perhaps those rocks you complain about?), which can reflect light back into the interior of the plants and help alleviate dark, moist conditions at the lowest garden level.
During dry times, water the new plants at their base, not with an overhead sprinkler system. While they need to stay moist as they’re first settling in and getting established, gradually back way off on the watering to encourage them to sink their roots deep into the ground, instead of staying near the surface; an extensive root system will help the plants avoid wilting in summer heat.
The Bay Bed
We’ve increased the size, height and width of your bay-window garden bed to increase your space and design possibilities. If a bed is too narrow, you don’t do much more than line up the plants in a row like soldiers. You don’t have to think in rectangles, as a bed that curves around that front corner will soften its lines and give the garden a graceful appeal. The way the bed mounds up from the flat ground (as a result of adding compost and amendments to improve drainage) has the added benefit of disguising the foundation of your home, while giving the plants the feel of embracing it. The bed’s height will also bring the plants closer to the window to improve your view when you’re inside looking out.
The steps leading to your front door may be a comfortable home for a pot of something like lemon balm, a useful culinary and medicinal herb that can be aggressive in the ground. If your steps aren’t wide enough to avoid tripping over it, tuck that pot into an empty spot in the bed, but check it occasionally to be sure it isn’t rooting into the ground through its bottom drainage holes.
A large shrub rose at the corner can also be trellised up to the roofline if you like. One to consider is a ‘Mutabilis’ rose, if you can find it; it does well here in Texas, where I live, and might also do well for you—and it’s fascinating. It gives the illusion of having different-colored blooms on it at the same time, because the flowers open yellow and then age to a deep pink.
The bay tree in the bay bed (no pun intended, but, hey, puns are fun) could take many years to reach the size shown here, but it is worth the wait. A bay laurel plant is hardy to about Zone 8, so if you live a bit further north in Alabama or have a particularly harsh winter, consider growing it in a container until it is big and robust enough to handle conditions in the ground. Consider it a pet.
Kathleen Halloran is a freelance writer living in beautiful Austin, Texas.
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