Garden Pots in Herbal Landscapes

In which to garden, containers provide a practical way to use a few square feet on a balcony or the front steps. In my case, my enthusiasm for herbs is so great that I’ve filled every inch of planting space in the garden and still want more. Containers allow me to create new outdoor tableaux when­ever I please, and I use them in all parts of my garden. Placed on a platform on wheels, large containers may be moved about at will; it’s pleasant to wheel them over to the barbecue or picnic table for meals outdoors. In a yard that’s short on sunshine, container herbs can even be moved during the day to catch extra rays. They can come inside, too, for a fragrant table arrangement designed to whet appetites. Try putting small terra-cotta pots of lush herbs on the table as decorative fresh seasonings; you can clip the tender tips over salads and other dishes.

Position containers at a height that minimizes kneeling and bending for easier tending. By tailoring the potting mix in each container to suit the herbs you plant in it and moving them to where they get the proper amount of sun, you optimize your chances of growing them successfully. And a container garden is virtually weed-free.

Gardeners can try out unfamiliar herbs in pots to test their flavors and evaluate their growth habits before putting them in the ground. I also enjoy having the option of creating change in the garden continually, just as I can by rearranging the furniture in the house.

The art of creating a container herb garden involves not only a knowledge of cultural requirements, but also an eye for combinations of flower, foliage, and form, the visual relationship between pot and plant, and the arrangement of plant groupings around a dramatic focal point. That’s easier than it sounds because if you don’t like the result, you can just move things around until they suit you.

Endless Choices

Options for containers are almost unlimited, and in my garden they range from the familiar terra-cotta to a stone urn for a special lavender plant. A formal garden might feature a grouping of miniature or standard herbal topiary in graceful stone or cast-iron planters. Rustic baskets or a strawberry jar with herbs spouting from its pockets create an informal country effect. Herbs look wonderful in container collectibles such as whimsical clay pots fashioned into animals or ceramic pots in a vibrant confetti of primary colors. Wine crates and barrels, wooden planter boxes, and large tile drainpipes make attractive homes for herbs. Commercial lightweight hypertufa troughs can hold a collection of miniature herbs (or make your own as described on page 38). Hollow logs and stumps can serve as rustic planters for shaded woodland herb gardens.

One friend of mine, author and photographer Rosalind Creasy, who lives near San Francisco, uses potted herbs very effectively in her ever-changing suburban yard. Leading the visitor to the front door in a welcoming way is a collection of colorful Italian tin cans planted with various herbs. The large tins, once containing olive oil, amaretto cookies, and coffee, now hold Italian parsley, Spicy Globe basil, oregano, rosemary, and silver thyme.

Just as important as choosing the containers is deciding which herbs to plant in them. Let your preferences guide you. A few well-chosen culinary herbs can supply a household with fresh sprigs and perhaps some to preserve. Sweet basil, tarragon, chives, and the slow-bolting cilantro are good choices for the summer sun. Or try some of the myriad varieties of basils together: the diminutive Piccolo basil, so good for pesto, looks wonderful planted one to a pot and used to circle the other basils like a little hedge.

I look for eye-catching combinations of color and shape. Try the lively kelly green of curly parsley with the dark green needle-leaves of rosemary; the stoplight green of Lime thyme against the neon of variegated golden sage; the rich burgundy of Dark Opal basil silhouetted against grass-green sweet basil and baby lettuces. A single fat cabbage planted in a shallow terra-cotta pot surrounded by a trailing nest of caraway thyme makes a delightful edible statement.

Contrasting leaf shapes add interest and movement to a collection. Winter savory, German chamomile, and salad burnet, planted together in a large pot, or Berggarten sage planted with sweet marjoram and thyme are two ­excellent drought-tolerant trios for full sun. Surround them with separate pots of creeping rosemary, Waller’s Munstead lavender, and curry plant ­(Hel­ichrysum angustifolium).

Culinary herbs grouped according to different ethnic cuisines such as Mexican, Italian, French, Chinese, Thai, or Vietnamese are companionable as well as convenient. Start with your favorites and add some new ones every year.

An arrangement of Oriental herbs for a shady spot could contain Vietnamese balm (Elsholtzia ciliata) in a large pot surrounded by pots of Vietnamese coriander (Polygonum odoratum) with its faint paintbrush line of burgundy striping the leaves, and variegated houttuynia (Houttuynia cordata ‘Variegata’) with its larger pattern of burgundy and green.

Edible flowers are an important component of my herb gardens. A delicious sunny spring container planting could consist of chervil tucked in among young lettuces and violas–­perhaps the familiar royal purple, yellow-splashed Johnny-jump-ups or the petite blue-and-white Cutie. These cool-weather plants can be moved to the shade as summer approaches. The soft salmon of Peach Melba nasturtiums nestled next to Revlon-red Queen of Hearts dianthus is a dazzling color combination. In the summer sun, the claret heads of Rossana radicchio call for attention when planted with the lacy green foliage and massed lemon yellow single blossoms of Lemon Gem marigolds (Tagetes tenuifolia).

I like to group plants with variegated foliage or scented leaves, or different herbs with the same or similar flower colors. A lemon-scented collection could include separate pots of lemon thyme, catnip, balm, basil, and verbena ringing or massed in front of a pot of tall lemongrass.

Mints are among the best herbs for a container collection. Apple, grapefruit, pineapple, lime, lavender, orange bergamot, and chocolate mint–their names sound like the flavors in a candy store–are only a few. They’re easy to grow, and keeping them in pots is a perfect way to check their invasive growing habits. I like to have them right outside the back door so I can snip a bit for iced tea or a lot for Thai chicken.

Scented geraniums do well in larger pots; my favorites include rose, Rober’s Lemon Rose, coconut, ginger, lime, and chocolate mint. I give them partial shade, but in cooler climates they do best in full sun. They are excellent for hanging baskets placed low enough so that the leaves can be touched to release their delightful fragrance. Also beautiful in a hanging basket is the nonculinary Origanum ­rotundifolium. When in bloom, its decorative soft pink and green shrimplike bracts cascade from its container like pastel firecrackers.

A small ornamental alpine garden in a fast-draining hypertufa trough could contain edelweiss (Leontopodium alpinum), Thymus serpyllum, pink-flowering Dianthus ¥ ‘Spotti’, and blue-flowered Aquilegia flabellata planted next to Viola sororaria ‘Freckles’.

Grasses and grasslike plants such as vetiver, lemongrass, society garlic (both plain and variegated), and low-growing buffalo grass (Hierochloe odorata) look good in container arrangements, either standing alone or as ­dramatic punctuation in a grouping.

Herbs with variegated foliage add life to containers of green herbs with insignificant flowers. An obvious but compelling combination is the sunny trio of variegated golden, purple, and creamy tricolor sages. Also consider pairings of textured foliage with interesting leaf structure such as ornamental Salvia argentea with its woolly, silver leaves, contrasted with the serrated, pointy leaves of edible purple perilla. Another striking trio combines the light green succulent leaves of Cuban oregano with dark-leaved, yellow-flowered Mexican tarragon (Tagetes lucida) and colorful miniature ornamental peppers.

Care and Feeding

Unlike plants in the ground, container herbs are entirely dependent on the gardener for all their needs. They can’t reach out with their roots for ­nutrition as they do in the ground, so they must be fertilized more often. Because their roots are above ground, they need protection from extremes of cold and heat. They demand more frequent watering because the soil warms up and dries out faster. At the same time, the soil mix must drain quickly so that roots don’t become waterlogged. Fortunately, it is easy to supply these needs for a good growing environment.

Choose a pot suited to the size of the plant. Transplant seedlings into increasingly larger pots as they grow. The final container should be large enough for the herb’s roots to grow and to allow air and water circulation. I find that 9 inches deep by 14 inches in diameter is minimum; otherwise, the plant dries out too quickly–one missed watering and it’s history.

Strawberry jars are excellent for collections of drought-tolerant herbs such as purple sage, chives, rosemary, and Cuban oregano, but it is difficult to water them evenly. Here’s a tip to make it easier. Before planting, cut a 1- to 2-inch-diameter PVC pipe slightly shorter than the height of the strawberry pot and cap one end. Stand the pipe, capped end down, in the jar and mark it at the level of each pocket opening, then drill small holes in the pipe at the level of each mark. Replace the pipe in the jar, fill it with small stones, then fill the container with moistened potting mix, planting your herbs as you go. When you pour water into the pipe, it will seep out at the different levels where it belongs instead of concentrating at the bottom of the pot. Rotate strawberry pots frequently so that each side receives the same amount of sun.

Before reusing old containers, sponge or scrub them with a solution of equal parts vinegar and water, then wipe them with water to which you’ve added a small amount of bleach; this will help prevent disease.

Soak unglazed terra-cotta, concrete, untreated wood, or other porous containers in water before adding potting mix so that they absorb water. If filled when dry, they will pull moisture out of the potting mix. Nonporous containers made of plastic and glazed ceramic do not permit free passage of air and water through their sides, so good drainage is essential and overwatering must be avoided. But in hot or very dry climates, the water-­retentive value of nonporous containers is a plus.

When planting a basket with herbs, line it with heavy black plastic that you’ve punched holes in to ensure that the entire mixture drains evenly. If you acquire a lovely antique pot that you don’t dare drill a hole in, you can still use it by placing a layer of pebbles or aquarium charcoal several inches thick at the bottom. Water the plant ­judiciously, just enough to moisten soil, then allow time for water collected at the bottom to evaporate before watering again. Moisture-retaining polymer granules can be mixed in the soil to great advantage when using antique pots as containers.

Good drainage is perhaps the most important factor for growing herbs. They are generally forgiving, but chronically soggy soil is a sure prescription for root rot. Garden soil drains too slowly to use in containers, but the soilless mixes available at nurseries and garden centers are formulated to drain fast yet retain moisture and nutrients long enough that plants can utilize them. These usually contain peat mixed with sharp sand, perlite, and/or vermiculite, with a little limestone added to neutralize the acidic peat. Fill containers with moistened mix to within 2 inches of the top of the pot. The lightweight white ­pebbles of perlite will rise to the top of the soil when watered; if you don’t like the spotty look, add a layer of small rocks, sphagnum moss, or small wood chips, which will also serve as an earth-cooling mulch. Where summers are hot and humid, rocks or sand are less likely to encourage fungal diseases than organic mulches.

Water your containers according to the finger test rather than the calendar. If the top few inches of soil are dry, water. During hot spells, or for plants in a constantly sunny location, test the soil daily. Use a gentle spray to avoid parting the mulch or disturbing the roots. When the soil starts to bubble and water runs freely out the drainage holes, you know the soil is saturated.

It is best not to use saucers under pots (unless they happen to be sitting on your Chippendale table) except in the most arid climates; when water collects, root rot is more likely. With most plants, I allow the soil to dry out, no matter how long it takes, before watering again. Watering early in the day gives leaves time to dry before nightfall, making them less inviting to disease organisms. Elevating containers on bricks or plant stands allows good air circulation.

Container herbs thrive on a constant supply of nutrients. Some gardeners use a half-strength solution of 20-20-20 soluble fertilizer every ten days to two weeks; others prefer time-release granules, which can last for an entire season. Organic substitutes include a weak manure tea, fish emulsion, or liquid seaweed fertilizer.

Here in southern California, many of my potted herbs overwinter fine outdoors, but I can easily carry the ­tender ones inside or to a sheltered location if cold weather threatens.

Pots in the Landscape

In container groupings, place the smaller pots at different heights to add interest. Recycle old benches, tables, and chairs as outdoor plant stands. Found objects, garden ornaments, and artifacts such as concrete globes, marble busts, sundials, bird feeders, and sculpted animals incorporated into these groupings can personalize your design. A stepped metal plant stand filled with useful culinary herbs is handy and decorative situated next to an outdoor cooking area on the patio or terrace.

Interesting container herbs can create a focal point in the garden or surround an existing one. For example, placing small topiaries of rosemary and thyme in front of a water garden and a large pot of strappy lemongrass behind it draws the eye to a restful scene. Herbs of the same genus or species look super all lined up in a row like soldiers along a driveway, against a blank wall, or underneath a window. Rosalind Creasy, in her backyard, creates inviting oases by grouping herbs and ornamentals around a pretty chair, table, or colorful garden bench. These areas beckon the visitor to sit and rest a moment, perhaps to settle in with a good book and a glass of lemonade.

When combining groups of pots, consider the form, foliage, color, and texture of each herb separately, then begin to envision various combinations. Because they’re in containers, you can arrange and rearrange to your heart’s content. Eventually, you’ll find something you like.