Herbs make a great addition to a garden, but they can also be grown indoors.

You can grow them as year-round houseplants or just in winter to protect tender herbs such as basil.

Choosing the right herbs is crucial for success. Some herbs thrive in containers, while others struggle.

Great options for indoor herb gardens include chives, basil and cilantro.

Avoid herbs with large root systems such as horseradish, fennel and lovage.

Herbs like tarragon are toxic to dogs and cats and should be avoided in homes with pets.

Herbs have specific requirements for growing indoors.

Most herbs need six hours of direct sunlight.

Place herbs in a sunny location near a window with a southern exposure or place them six to 12 inches from two 40-watt, cool white, fluorescent bulbs for 14 to 16 hours.

Keep herbs in rooms with temperatures of at least 65 to 70 degrees during the day and 55 to 60 at night.

Although most herbs can survive temperatures in the mid- to low-40s, others cannot.

Basil cannot survive temperatures lower than 50 degrees and should not be kept on windowsills during winter months.

Herbs that are not exposed to preferred light conditions will become spindly, produce smaller leaves, and have a reduced aroma.

Herbs require a balance between a humid environment and adequate air circulation.

Air that is too low in humidity will cause leaves to dry out, while too much humidity can lead to root rot and other fungal issues.

Plant herbs in containers with drainage holes and in a potting mix that will aid water drainage.

Water the potting mix when it starts to dry out.

Specific herbs such as marjoram, oregano, sage, thyme and rosemary should dry out slightly between waterings.

When growing basil, never allow the potting mix to dry out completely.

Fertilize herbs with a low dose of water-soluble fertilizer every two weeks.

Fertilizing herbs more often may negatively affect the herb’s aroma and taste.

If using an organic fertilizer, check the ingredients before applying.

Some organic fertilizers have a pungent fishy or manure-like scent that can be unpleasant indoors.

Cultural and mechanical methods should be used to control pests.

Flying insects such as fungus gnats can be controlled by placing yellow sticky traps near the infested plants and using proper water techniques.

For insects like aphids, trim off the infested branches and dispose of them.

Soft insecticides such as neem oil can be used, following all label directions, in extreme cases, but this is not typically recommended as herbs are meant to be regularly harvested and eaten fresh.

Always wash leaves before you use them.

Re-pot herbs when roots grow through the drainage hole.

The best time to re-pot is in the early spring so that herbs can grow into the new medium during the growing season.

Perennial herbs can be re-potted several times to accommodate new growth.

Any herbs with a taproot, such as borage and dill, should be grown in deep pots.

Herbs with a more trailing form can be grown in hanging baskets.

If you would like to place your herbs in containers outside during the late spring and summer months, they will need to be slowly acclimated to the higher light and wind intensity of the outdoors.

By cultivating herbs indoors, you can enjoy them throughout the year.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613