Growing Herbs in Containers - U of I Extension

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Growing Herbs in Containers

This article was originally published on April 14, 2010 and expired on July 31, 2010. It is provided here for archival purposes and may contain dated information.

Growing plants can be a great deal of fun especially if the plants are easy to care for, said a University of Illinois Extension horticulture educator.

"Plants that grow in my yard must do so with minimal care," explained Jennifer Fishburn. "That's why my favorite group of plants is culinary herbs. Not only do these plants add a variety of color to the landscape and are good filler plants in perennial and herb gardens, they add flavor to your favorite food dish.

"Growing herbs in containers can be fun, add variety, fragrance and a splash of color to a deck, balcony, patio or any small space. Herbs can be used alone in containers or mixed with annual flowers or vegetables."

So what kind of container is need? The answer is anything that will hold potting media and has drainage holes. Drainage holes are an absolute must. The container should compliment and not compete with the plants that will be placed in it and should blend with the surroundings.

If you have used a container before, it is best to wash and sterilize the container before use. Wash with soapy water and sterilize with a1 part bleach to 10 part water solution.

"Select a container large enough to allow space for root growth," she said. "For good root growth, most herb plants will need a soil depth of six to eight inches. Taller plants such as dill and fennel need at least a depth of 10 inches. To save on the amount of potting media needed, fill the bottom of deeper containers with sweet gum balls."

What kind of growing media? Plants grown in a container grow best in good quality potting media. This mix should be sterile, have the ability to retain moisture and allow for aeration at the same time. Container grown plants will need fertilizer throughout the growing season. Purchase a potting media with slow release fertilizer or use a soluble complete fertilizer after planting. Apply soluble fertilizers at a low application rate. Too much fertilizer will cause herb plants to grow quickly reducing flavor and aroma.

"What herbs will grow best in containers? Herbs with compact growth habit," she said. "Drought-tolerant herbs do particularly well in containers. Tender perennial herbs such as rosemary are good choices as well. Plants with a trailing habit look nice cascading over the edge of a pot.

"For some fun, pick a theme for your container."

Here are some theme ideas to get you started:

  • Chocolate covered strawberries: chocolate mint and a strawberry plant.
  • Lemon drop: lemon basil, golden lemon thyme, lemon grass, lemon balm and lemon verbena.
  • Pizza garden: oregano, sage, thyme, marjoram and winter savory.
  • Kitchen corner: thyme, lavender, sage, oregano, parsley, rosemary and chives.

"How many herbs will fit in a container? A 12-inch container will hold about three or four herb plants while a 15-inch container can support about five or six plants," said Fishburn.

Herb plants grow best in a full sun location that has some late afternoon shade.

How about watering? The most important thing to remember is that container gardens must be watered. The most common problem with container gardens is under or over watering. Over-watering may promote root rot, fungal problems or fungus gnats. Symptoms of over-watering include wilting and reduced growth. Under-watering symptoms include wilting and scorching. As with over-watering, repeated wilting will stunt growth.

Apply water until it runs out the drainage holes. Containers dry out quickly so check containers at least twice a day on hot, dry, windy days.

"Harvest herbs regularly to keep the plant growth compact and bushy," she said. "Herb plants are fairly easy to maintain, can grow in almost any full sun location and give gardeners the satisfaction of eating the fruits of their labor."

Source: Jennifer Fishburn, Extension Educator, Horticulture, fishburn@illinois.edu

Pull date: July 31, 2010