How to grow lavender indoors

Native to the Mediterranean region, lavender (Lavandula spp.) is a small, woody ornamental shrub known for its soothing fragrance. It’s used worldwide in various ways, most commonly as an essential oil in personal care products such as soaps and perfumes, and in a new trend, as an accent in foods.

Growing lavender indoors is a rewarding challenge, and should be attempted after success with other indoor favorites such as basil, radish or lemongrass.

Uses for lavender

Lavender has been domestically grown for millennia, for a number of applications:

  • The first documented use of lavender was by the Romans as an insect repellant and to soothe bug bites. (Perry, n.d).
  • The word lavender derives from the Latin root lavare, which means ‘to wash.’ Ancient and dark age cultures used lavender in the laundry for cleaning and fragrance (Klingaman, 2012).
  • Like tea tree oil, lavender is an antiseptic. Lavender oil was used on the frontlines to treat wounds in World War I (Butje, A., Repede, E., & Shattell, M., 2008).
  • In foods, lavender is a delightful accent in desserts and ciders Also, it combines well with other Mediterranean herbs such as rosemary and thyme to flavor savory dishes like stews and roast chicken.

Indoor growing conditions

Success with lavender indoors starts with bright light. Place lavender plants in a sunny, south-facing window where they can receive 6-8 hours of sunlight daily. If needed, use a grow light to supplement light conditions.

Lavender can take a lot of heat, and it is best to keep it and most indoor plants away from air vents. Ideal indoor growth temperatures for lavender shouldn’t dip below 50 degrees at night.

What to plant - Plants or Seeds

Growing established plants is the easiest method for starting lavender at home. Select varieties that can handle cooler environments and some moisture such as English lavender (Lavandula angustifolia).

Plants will be for sale in garden centers and online in the spring and often during the holiday season. Starter sizes vary from 2” pots to one gallon, and organic plants are often available. Plants grow slowly, so purchase the largest selection that your space can handle.

Growing lavender by sprouting seeds is possible but is a challenge due to lavender’s long germination time and aversion to moisture. Choose seeds that are packaged for uniform growth.

Image: Ed de Quincey

Container planting supplies

Lavender thrives in low-humidity conditions and needs a different soil medium than most plants. Basic potting soil will promote root rot in lavender, so create a custom mix by blending a 1:1 ratio of regular potting soil with cactus/succulent potting soil which contains small gravel and sand. Sand and gravel promote fast drainage which allows the potting medium to dry out faster and avoid root rot.

Choose an unglazed terra cotta clay pot that is only slightly bigger than your plant’s roots. Unglazed terra cotta allows excess moisture to filter from the root zone through the sides of the pot. Make sure the container has a drainage hole. To keep things neat, purchase a matching drainage saucer, and empty the saucer after watering so the plant won’t draw standing water back through the soil.

How to plant in containers

Planting lavender in containers follows the same guidelines as potting up other indoor plants: 

  1. Begin by laying down newspaper or an old shower curtain on your potting surface. This makes cleanup a breeze.
  2. The lavender root ball should be level with the soil once planted, and the soil level should be ½” to 1” below the edge of the pot. Add enough soil to the pot to lift the plant to the desired height.
  3. Remove the lavender plant from the pot it was sold in, and place on the soil in its chosen container. Add soil mix around the rootball, but don’t cover the top of the rootball. Softly tamp the soil down around the plant to help the soil settle.
  4. Water thoroughly. Even though lavender prefers drier conditions than most plants, add water until it flows through the pot’s drainage holes during transplanting. 

Caring for indoor lavender

The keys for lavender success indoors include providing plenty of direct light, at least 6-8 hours daily, and monitoring the moisture content of your plants. Lavender prefers less water than most plants grown indoors. Water infrequently, only when the top inch of the soil is dry. However, don’t allow all the soil to dry out. Space plants so that they are not touching each other and air can freely circulate around them.

Lavender plants that receive too much water may develop powdery mildew or succumb to root rot. Powdery mildew looks like powdered sugar at the base of the stem and lower leaves. It is eradicated organically with fungicides that contain the non-toxic bacteria Bacillus subtilis. After treatment, reduce watering and give the plant more light.

Root rot occurs when the soil is continually saturated, creating anaerobic conditions that suffocate the roots. Prevention is the best treatment for root rot, which is why soil should dry slightly between waterings.

Like other woody Mediterranean shrubs such as rosemary or juniper, lavender actually thrives on poor soil with fewer nutrients. Once established (meaning that the plant is rooted and putting on new growth), fertilize with a higher-nitrogen liquid formula every 4-6 weeks. Avoid over-fertilization.

Lavender is a slow grower. Harvest material as new growth is produced, and before flowering when the leaves contain optimal levels of essential oils. Never harvest more than 20% of the overall plant, and wait for harvested volume to regrow before the next pruning. Lavender stems can be thick, so plan to harvest with sharp hand pruners rather than kitchen scissors.

Lavender sprouting and Microgreens

Microgreens are defined as sprouted plants that have 2-4 leaves. Microgreens contain flavors associated with mature plants without woody or tough textures, and are a delightful addition to many foods. Keep in mind that lavender takes two weeks to germinate, and will take another two weeks or more to achieve microgreen status.

As with mature lavender plants, lavender seeds prefer well-drained soil. To plant, fill a seed tray with a soil medium specifically labeled to sprout seeds. Scatter the seeds evenly across the surface and gently sprinkle with ⅛” covering of soil. Water by using a fine water mist spray bottle until saturated. Place in a sunny spot, or under grow lights, and use a seedling heat mat if needed to keep soil temperature between 60-80 degrees Fahrenheit.

After initial planting, make sure seeds have enough moisture but aren’t waterlogged. This is best achieved by thoroughly misting the seed tray in the morning and early evening. Monitor so that the soil doesn’t dry completely, and do not fertilize. Lavender microgreens can be harvested at any point after the seedling has developed four leaves.

Conclusion

Generations have cherished lavender for its beauty and many useful properties. It flourishes in full sun, low-humidity environments with fast-draining rocky soil. Replicating these Mediterranean environmental traits indoors will encourage lavender to thrive, encouraging its signature aeromatic goodness to flourish in your home.

References

  1. Butje, A., Repede, E., & Shattell, M. (2008). Healing scents: An overview of clinical aromatherapy for emotional distress. Journal of Psychosocial Nursing and Mental Health Services, 46(10), 46-52.
  2. Klingaman, G. (2012). Plant of the week: Spanish lavender. University of Arkansas Division of Agriculture Research and Extension, Cooperative Extension Service.
  3. Perry, L. (n.d.). Growing and using lavender. University of Vermont Extension, Department of Plant and Soil Science.

Feature image: Mike Green