Herbs can also be grown indoors for year-round enjoyment. Growing herbs indoors is no more difficult than growing them in the garden.
Indoor plants will need essentially the same conditions as herbs grown outdoors — sunlight and a well-drained soil mix that is not too rich.
Select a south or west window. Different herbs have different light requirements, but most need a sunny location; in winter, “grow lamps” or fluorescent lamps are helpful in supplementing light.
When planting, mix two parts sterilized potting soil and one-part coarse sand or perlite. To ensure sweetness of the soil, add a cut of ground limestone per bushel of soil — or 1 teaspoon of lime per 5-inch pot. There should be an inch of gravel at the bottom of each pot to ensure good drainage.
Consider the water needs of each herb. Growing plants need more water as do plants in clay pots or hanging baskets. Misting and grouping the plants on a tray of moistened pebbles will help keep them in a humid condition. Don’t drench herbs — avoid getting herb roots soggy.
Annual herbs can spend their full life cycle in a pot indoors. Perennial herbs, however, will do better if you place them outdoors during the summer. Plunge the pot in soil up to its rim, or keep it in a protected location on the porch or patio.
Herb plants need sun during the summer months, so place them accordingly. To prevent the loss of foliage and avoid plant damage, bring herbs indoors before frost. A light frost is helpful on mint, chives, and tarragon; it tends to induce a rest period and make the resulting new growth firm and fresh.
You can maintain an indoor herb garden indefinitely by periodic light feeding, yearly repotting, renewing annuals, seasonal moves outdoors for perennials, and occasional pruning. Water plants as needed. Use several planters or a divided one to allow for different moisture needs of plants.
Source: WVU Ext.