Train vining herbs up onto a trellis, arbor, or pergola to maximize your use of space. Passionflower, hops, raspberry, jiaogulan, and climbing roses are a few possibilities. Hops can grow to gigantic proportions, so you’ll probably need to tame it by cutting it back, or give it a large fence or wall of a building. Many of these vining herbs also spread by runners and can quickly take over a garden. Planting in containers can help limit their spreading. Another option is weeding out the runners a few times a year.
Passionflower growing up twine on a large trellis.
Maximize Herbal Yields Through Repeated Harvesting.
Certain herbs can be harvested multiple times throughout the year, in a “cut-and-come-again” style (similar to microgreens cultivation). Give these plants a “haircut” early enough in the season, and they grow right back. I harvest the following herbs in this fashion, two to three times during the growing season: gotu kola, holy basil, spilanthes, thyme, California poppy, passionflower, comfrey, basil, rosemary, chickweed, violet, lemongrass, sage, boneset, bee balm, meadowsweet, anise hyssop, and lemon balm. Growing these cut-and-come-again herbs can effectively double or triple your yield for every square foot of precious dirt, and make them fantastic medicinal herbs for urban gardens.
August 2021 Safety Update: Boneset and comfrey contain pyrrolizidine alkaloids (PAs), which can be harmful to the liver over time when ingested internally. Recent research shows that the PAs found in these plants (and other PA-containing plants) can be taken up by other plants when grown in close proximity or when comfrey is used in the garden as mulch or fertilizer. In light of this, we are recommending that comfrey should not be interplanted with herbs or food plants in the garden that will be ingested or used as mulch or fertilizer to err on the side of caution. However, mature compost that includes comfrey does not seem to contain PAs once it has been fully composted according to this study.
Lemongrass (Cymbopogon sp.), artichoke (Cynara cardunculus var. scolymus), and purple sage (Salvia officinalis ‘purpurascens’) growing in a glazed terra-cotta pot in my former gardens.
Think Inside the Box. Container Gardening is Perfect for Urban Herb Cultivation.
A time-tested solution for growing in a limited space is container gardening—basically, planting in a “box.” Larger ceramic pots, retired bathtubs (make sure they are lead-free), and wooden barrels can hold a surprising number of herbs, especially if trailing herbs are planted at the perimeter and taller plants at the rear. Shade-loving herbs that are suitable for growing in pots include aloe vera, black cohosh, gotu kola, and jiaogulan. Consider planting ornamental herbs and edibles in containers—chives, nasturtium, purple sage, tricolored sage, variegated thyme, spilanthes, calendula, lemongrass, and basil are especially snazzy botanicals. Plan for varying heights, and more plants can grow companionably. Please see my article Growing Medicinal Herbs in Containers for more tips on cultivating medicinal herbs for urban gardens.
