When it comes to multi-taskers, perennials herbs are at the top of the list. Perennial herbs, which return year after year, are useful plants that can be used for their culinary, medicinal or aromatic properties. Perennial herbs are easy-to-grow plants that add texture and variety to the flower bed or herb garden. Sturdy, pest-tolerant plants, many herbs will attract butterflies, bees or hummingbirds to the garden and will thrive in poor soil, as long as it drains well. While many perennial herbs will survive outdoors all year 'round even in cold climates, some will need to live indoors during the winter months.
Planting Herbs in the Garden
Select a planting site where perennial herbs will be exposed to bright sunlight for at least 6 to 8 hours every day. Herbs require well-drained soil, so avoid planting herbs in clay soil or in soggy soil with poor drainage.
Purchase herb plants at a garden center or greenhouse that specializes in herbs. Select compact, healthy plants with even color. Avoid spindly plants or plants with yellowing or brown leaves. Save the tag from the plant's nursery container, as it will provide practical information that you may need later.
Use a shovel or a trowel to dig a hole for each plant. The hole should be no deeper than the plant's root ball, as herbs planted too deeply will be more susceptible to rot. Place the plant in the hole, fill the space around the roots with the same soil and pat the soil lightly around the roots. Spacing will depend on each individual plant, but should be based on the plant's mature size. In general, plants require at least 6 inches of growing space.
Water the herbs immediately after planting. Keep the soil evenly moist until you see new growth. After that time, water the plants deeply once every week, then allow the soil to dry out before the next watering. Watering to a depth of 8 inches will ensure that the roots receive enough moisture.
Fertilize perennial herbs once every year, in spring, using a regular liquid fertilizer mixed to half of the strength recommended on the label. Herbs are light feeders, and plants fertilized excessively will produce lush foliage at the expense of flavor and aroma.
Spread 2 to 5 inches of mulch, such as straw or pine needles, around the plants in late autumn to protect the plants during the winter months. Check the nursery tag for specifics, as some plants may need to be planted in containers and moved indoors during the winter months in cold climates.
Planting Herbs in Containers
Fill a pot with commercial potting soil. To improve drainage, add a handful of perlite or sand. Any sturdy pot with drainage holes in the bottom will work.
Dig a hole in the soil with your hand or a trowel. Plant the herb in the hole at the same soil level at which it was planted in its original container.
Water the plant immediately. Keep the soil moist until you notice new growth. After that time, water whenever the top of the soil feels dry to the touch, until liquid drains through the drainage hole. Pour out any water remaining in the drainage saucer, and never allow the bottom of the plant to stand in water. If the pot is outside during hot weather, check the potting soil daily.
Place the plant outdoors as much as possible. Although perennial herbs can be grown indoors all year 'round, they will benefit from fresh air and sunlight.
Bring herbs indoors before the weather freezes. Place the pot near a sunny window. If light levels are low during the winter months, place the plant under a grow light for 12 to 14 hours every day.