Cilantro. Rosemary. Bay laurel. In a garden, each of these plants needs different conditions to grow well. After all, a delicate cilantro plant needs more TLC than a sturdy bay laurel tree. But in a kitchen, they share a purpose.
"The only thing that culinary herbs have in common is that they have leaves that are used for seasoning food," UC Master Gardener Ann Ranish said. "Some of them are annual — that is, they are very short-lived — and others are trees that go on for years, like a bay leaf tree."
As a Master Gardener, Ranish is a volunteer trained by the University of California to serve as a teacher and resource for local home gardeners. She periodically teaches a culinary herbs class for the Master Gardeners program.
Ranish's class focuses on roughly 20 different herbs, which she categorizes into groups based on characteristics such as lifespan and water needs. While many herbs are easy to grow, they have their own unique needs, and by understanding the basics, new gardeners can help their plants thrive.
Herbs such as cilantro and dill tend to be short-lived and need large amounts of water. These herbs can also be paired well with ornamental plants. In contrast, shrubs like rosemary and bay laurel often live a lot longer, and don't need to be fertilized every year.
Though many herbs require different conditions, it's OK to group those with like needs in the garden, Ranish's fellow Master Gardener Candace Simpson said.
She said that water-loving herbs like parsley, basil, cilantro and chervil can be grown together, while the low-water herbs thyme, oregano, sage, tarragon, chives make "a great grouping." But there's one herb that should be left on its own. "Rosemary grows to be a pretty large plant, and so is generally best put by itself somewhere, lest it smother smaller plants," Simpson said.
Ranish said a good strategy, especially for large or invasive plants, is planting herbs in a pot rather than in the ground. Pots can be used to grow any herb, and are ideal for larger plants because they ensure that plants stay a manageable size and provide better drainage. They also prevent invasive herbs like mint from driving out other plants.
Ranish also has used a container for basil, her personal favorite herb to grow.
"There's just nothing like fresh basil," she said. "It doesn't keep its flavor when it's dried. To me, it means summer, along with tomatoes."
While she's experimented with different conditions for growing basil, she's had the best results by using a self-watering container that uses a tube and gravity to bring the water to the bottom of the pot.
"The basil seeds just love being able to pull up that water from the bottom. I've discovered that's what basil really likes," Ranish said.
Simpson recommends planting the summery herb before the hottest weather starts.
"Basil is an annual, and cold sensitive, and is always planted in late spring (April-May) to grow throughout the summer," she said.
Whether a hardy shrub or a small, thirsty plant, culinary herbs have a lot of variety among them, but a couple of important practices will help most herbs be productive. In addition to adequate water, harvest herbs often and cut back plants, and occasionally, consider replacing them altogether.
"Let your taste be your guide on when to replace plants that have gotten overgrown, woody, and/or strong tasting, or simply aren't producing as well as you want them to. Don't be afraid to experiment with new herbs," Simpson said.
Maya Homan is an editorial intern. She can be reached at email@example.com.
The UC Master Gardeners hold an open house at the Palo Alto Demonstration Garden each Saturday, 10 a.m. to noon, where gardeners offer tours and answer questions. For gardening classes and resources, visit mgsantaclara.ucanr.edu.
Summer Herb Gardening
Here are some additional tips from Master Gardener Candace Simpson on culinary herb gardening in the summer, plus ideas for what herbs you can plant in the fall.
Protecting herbs from the heat
-Herbs that thrive on regular water — basil, especially — need constant water in hot weather. Regularly pinching back basil will help the plants be bushy and productive, and better able to stand up to the heat.
-Mediterranean herbs (thyme, oregano, sage, marjoram, tarragon, savory, rosemary) don't need special protection from typical summer temperatures. But even these plants need extra water during extreme hot spells.
When to plant
-Plant perennials (thyme, sage, tarragon, oregano, marjoram, winter savory, rosemary) from transplants in the early spring (March-April) or fall (Sept.-Oct.). They will live multiple years, though all herbs get rangy and woody with age, and many gardeners replace them every three to four years.
-Cilantro bolts (goes to seed) in hot weather, but you can plant it in late summer or early fall.