How to Grow an Indoor Herb Garden
You can savor the flavors of fresh herbs all year around by creating an herb garden on a windowsill.
Understanding where the plant grows well outdoors will give you great clues as to whether or not you can replicate those growing conditions indoors.
“When you bring a plant indoors you’re trying to mimic as closely as possible their natural habitat,” says horticulturist Susan Maki of Squak Mountain Greenhouses & Nursery. “If you think about lavender, they like rocky soil, hot sun, they’re not going to transition well to an indoor climate.”
So, what are the best herbs for indoor growing?
“You have the princess plants and then the flexible flyers — OK this is what I’m given, let’s make the best of it,” says Maki.
You can grow your plants from seed or pick up a few from your local nursery.
Maki’s recommends the following flexible flyers:
Synonymous with oregano, but milder, marjoram is a popular addition to salads, soups and meat dishes. It doesn’t like to be in full sun, so it should be placed a bit away from a sunny window or be set in an eastern window.
Frequently used in Latin American and Asian dishes, cilantro is sometimes referred to as “Mexican parsley” or “Chinese parsley.” Cilantro does well with a western or southern exposure, but it doesn’t like to be hot.
This delightfully fragrant herb is used in your favorite Italian dishes and is the basis of pesto. Basil requires a bright, sunny window. Maki says in the Northwest basil seems to do better indoors than outdoors.
Though it’s a relative of onions and garlic, chives is used for its mild leaves, not bulbs, and is used as a garnish in salads, soups and omelets. Chives will do well in a sunny spot or in a slightly shaded area.
Used in a variety of dishes as well as tea, the fast-growing mint will thrive anywhere. Maki calls it the “herb of the apocalypse” because it’s so adaptable. Pinch the tips off regularly to encourage bushiness.
Whether or not you frequently use your herbs in cooking, you still need to give them a good haircut. You don’t want them to bolt, commonly known as going to seed.
“The minute it starts putting out flowers and seeds the plant is putting all its energy into producing the flowers and seeds and the leaves become bitter,” says Maki.
Good pruning will prevent bolting and also produce a bushier, more compact plant.
Choose a potting soil that’s rich in organic matter and pots that have sufficient drainage. Your plants won’t like to have wet feet.
“The quickest way to kill a plant indoors is to overwater it,” says Maki.
“When you understand why the plant needs water it makes it so much easier,” she says. “Plants create their own food through photosynthesis. For the plant to photosynthesize they need light, water and nitrogen. When you alter the light as you have to when you bring a plant indoors you’re going to have to adjust the water. They’re not going to need as much water because there’s not as much light.”
Maki says the key is to check the soil regularly instead of just automatically watering.
“You’ve got to put your finger in it,” says Maki. “When the top inch of the soil is dry you water all the way through and let it drain.”
If you pick up the pot and it feels light that’s also a sign. Another trick is to put a pencil in the soil and if soil adheres to the eraser it’s moist and if no soil comes out you know it’s dry.
Once the roots start emerging from the bottom of the pot you know it’s time to transplant.
“Just go one size larger,” says Maki. “Larger than that the plant can’t take up enough water.”
If you don’t have a good window location you can use a grow light. There are many choices, from full spectrum LED lights to desktop gardens made specifically for growing herbs.
“There are even light bulbs that you can pop in a desk lamp,” says Maki.