Growing Lavender Indoors
Try your hand at growing lavender indoors. While this pretty herb isn’t a traditional houseplant, you can manage to keep it healthy if you do the right things. In most situations, lavender should be grown outdoors. Even in coldest regions where lavender isn’t hardy, it’s best to keep growing lavender indoors as a fall-back position, something you do in winter when plants can’t be outdoors.
Most indoor lavender plants don’t display ideal growth and leaf color, let alone colorful blooms. The problem is light—or lack of it. Indoor settings have a tough time delivering sufficient sunlight. This is especially true in northern regions in winter.
Place indoor lavender plants near a bright south-facing window. Most plants won’t fit on a window ledge, so use a small table or plant stand to get your plant near the sun. You can also use supplemental light to mimic sun. Standard fluorescent tubes suspended 6 to 12 inches above lavender provide sufficient light for growth. Or try high output fluorescent lights (T5 type), which yield twice as much light as traditional tubes.
When growing lavender indoors, using the right size container is important. A pot for lavender should only be one to two inches larger than the plant’s rootball. In a larger pot, there’s excess soil that doesn’t have any roots in it to help absorb moisture. That soil can easily become waterlogged and lead to too-wet soil where the lavender roots are. The end result is root rot, which is how many indoor lavender plants die.
Lavender is a Mediterranean plant, which means that it loves lean soil. Fill the bottom of your pot with an inch or two of limestone gravel topped with a basic soilless mix made for containers. Blend a tablespoon of lime into soil to give it more of an alkaline edge. Monthly, blend dried and ground eggshells into the top of soil to add lime.
Although lavender loves heat, indoors you’ll have better success, especially in winter, when you locate it away from hot or cold air drafts. In winter, consider growing lavender indoors in a room that’s cooler than the rest of the house. Aim to keep roots alive through winter, but not to push heavy new growth.
Water your lavender after planting, and then pull back on the water. During cooler winter months, water only when soil is dry to the touch about 1 inch deep. Consider using a terra-cotta pot for growing lavender indoors. The porous clay pot sides lose moisture, which can help prevent root rot.
Choose smaller lavender varieties for indoors. They adapt better to pot growing and also fit beneath a grow light. French lavender (Lavandula dentata) varieties grow well indoors. They’re not as fragrantly potent as English lavender (Lavandula angustifolia), but they adapt better to interior conditions. Other good types of lavender to grow indoors include Canary Island lavender (Lavandula canariensis) and fern leaf lavender (Lavandula multifida), which tolerates wet conditions better than other lavenders.
In spring, move lavender outdoors when all danger of frost has passed. Clip any spindly growth that grew over winter. Add a layer of compost to soil to jump-start growth and water well.