11 Common Lavender Growing Mistakes To Avoid This Season
Are you planting lavender in your garden this season? There are a number of different common problems that can impact how well your lavender grows. In this article, organic gardening expert Logan Hailey walks through the most common mistakes that befall many lavender gardeners, from beginners to gardeners with a seasoned green thumb.
When a summer breeze whisps the relaxing floral aroma of lavender through an open window, you can’t help but feel peacefully pulled into the present moment. There is nothing quite like a lavender garden in full bloom. This classic herb has been used for thousands of years for bouquets, culinary flavorings, herbal remedies, and bee-magnetizing ornamental gardens.
Yet, in spite of its effortless perfume, lavender isn’t always the easiest herb to grow. This Mediterranean perennial can cause a few issues for beginner gardeners who are unfamiliar with its growth habit, pruning requirements, or soil preferences.
Luckily, years of experience on the west coast’s top organic lavender farms have taught me some simple secrets to cultivating thriving lavender plants with vibrant purple (or white!) blooms.
Here’s how to avoid the most common lavender growing mistakes so you don’t have to learn the hard way (like I did).
- 1 Lavender Gardening Mistakes: An Overview
- 1.1 Growing in Poorly Drained Soil
- 1.2 Forgetting to Prune
- 1.3 Accidentally Cutting the Woody Parts
- 1.4 Over-Fertilizing
- 1.5 Not Enough Sunshine
- 1.6 Choosing the Wrong Variety for Your Climate
- 1.7 Forgetting to Protect From Hard Frosts
- 1.8 Not Enough Space Between Plants
- 1.9 Over-Watering
- 1.10 Not Checking for Fungal Diseases
- 1.11 Forgetting to “Deadhead” Old Flowers
- 2 Final Thoughts
Lavender Gardening Mistakes: An Overview
Despite its elegant appearance and decadent aroma, lavender is a surprisingly easy herb to grow. This perennial herb is native to the Mediterranean, where it thrives in the arid, rocky slopes beneath the hot sun.
As you can imagine, growing it in other climates requires a bit of adaptation to keep it happy. But once established, harvesting and pruning are the only real maintenance required. If you study these common pitfalls, you can set your lavender garden up for success from the beginning.
Already have an established lavender planting? Don’t worry, these quick fixes can also help revitalize dwindling blooms, spindly or woody growth, and reduced vigor.
Let’s dig into the 11 mistakes you might be making with your lavender:
Growing in Poorly Drained Soil
The number one most common mistake with lavender is planting it in soil that doesn’t drain. This Mediterranean herb absolutely hates soggy or waterlogged soils and becomes increasingly susceptible to root rot and fungal diseases when its roots are too wet.
Planting lavender in a small hole or compacted clay soil can have detrimental effects on the plants growth. Beginners often forget to properly amend and prepare the soil ahead of time to ensure that lavender has plenty of air flow and drainage in its root zone.
How to Avoid It
Before planting lavender, prepare a hole that is two to three times as big as the plant’s root ball. Use a broadfork or digging fork to loosen the surrounding soil and generously amend with sand, bark-based compost, peat moss, or fine gravel.
If growing in a compacted clay soil, consider making the hole even deeper and wider to make sure that water doesn’t end up accumulating below the lavender root ball.
When in doubt, add more small rocks or sand. Believe it or not, this tender flower often grows best in the rocky or gravelly soils of its wild habitat. That way, rainfall can move swiftly through the soil profile instead of sitting in the root zone and creating soggy conditions.
Forgetting to Prune
As an herbaceous perennial, lavender requires regular pruning to stay aesthetically pleasing and healthy. Most gardeners prefer lavender’s signature elegant domed shape with lovely long-stemmed flowers that look beautiful in bouquets and arrangements.
But just like your gym workouts, maintaining an ideal lavender physique takes a bit of work. If you forget to prune lavender, the growth can quickly become woody, spindly, or awkwardly misshapen.
Many gardeners avoid pruning out of fear of hurting the plant, or they prune too lightly. When left to its own accord, lavender becomes unwieldy, unsightly, and may fall over or split from the base. If you forget to prune lavender at least once per year in the spring, the plant may overgrow or become highly misshapen.
How to Avoid It
To maintain proper shape and growth, lavender should be pruned fairly heavily in the spring of every year, and ideally again in the fall. Don’t be afraid to prune with a “heavy hand”, as long as you avoid cutting into any wood. This creates a prettier shape with more vigorous blooms.
After the first flowering, you can cut the green part of the plants back ⅓ to ⅔ of the way down. Use your loppers or shears to create a domed “gumdrop shape”. In the fall, prune again by cutting back the gray-brown “sticks” that remain on the plant to encourage lush new growth in the spring. The fall pruning should be more gentle to ensure the plant has enough greenery to sustain itself through winter.
Accidentally Cutting the Woody Parts
The golden rule for pruning lavender is to only cut green growing plant parts and never (never!) cut into the woody growth. This can damage or even kill the plant with shock.
Lavender is an evergreen perennial in zones 5-10, which means it keeps (and needs) its leaves throughout the winter. When you cut into the woody base, you’re cutting off the leaves that lavender needs to sustain itself through the winter.
While pruning is known to encourage new growth, some gardeners get a little overzealous with their loppers. Pruning the lavender too low and cutting into the woody part of the plant is a major mistake that can severely injure your lavender. If you think of the woody base like the trunk of a tree, it makes sense why damaging the trunk might really harm the plant.
How to Avoid It
As a rule of thumb, only prune the green parts of lavender. For spring or summer prunings, grab handfuls of spent flower stems and snip them off about ⅓ of the way down, leaving ⅔ of the green growth and always avoiding the woody growth beneath. Use your shears to create a nice rounded shape over the top of the plant.
Unlike our common garden veggies, too much fertilizer isn’t the best for lavender. Over-fertilizing (especially with nitrogen) results in an excess of foliage and reduced bloom production. I assume you want to grow lavender for its alluring fragrant blossoms, so be careful how you amend the soil surrounding this herb.
In an attempt to promote lots of growth, beginner growers often dump on the fertilizer at the time of planting lavender. But adding high nitrogen fertilizers or manure-based composts can promote rapid or even excessive leaf growth with fewer flowers.
How to Avoid It
Don’t fertilize lavender. It typically gets all the nutrients it needs from the native soil. If you need to add organic matter to improve the drainage of clay soils, use peat moss, coco coir, sand, or vermiculite. If using compost, opt for a fungal-rich bark-based compost that is not made with manure.
Not Enough Sunshine
It should come as no surprise that this cheery fragrant herb craves sunlight. Lavender evolved in high elevation rocky regions of the Mediterranean where the sun shines hot and vibrant almost year round.
If you accidentally plant lavender in the shade of trees or structures, it may have less fragrant flowers, disappointing growth, and a lack of overall vigor. Lavender needs at least 8-10 hours of direct sunlight per day and prefers southern exposure.
Beginner gardeners often plant baby lavender plants in an area on the margin of their garden that looks sunny, but later grows into a denser canopy. The result is too much shade for the herb to thrive. Planting lavender too close together can also lead to competition for light.
Lavender grown in shady conditions may exhibit pale or dying leaves, low flower production, flowers lacking fragrance, or slow growth.
How to Avoid It
Observe the solar aspect (how the sun moves over your garden) of your planting area. Notice areas that get too much afternoon shade from trees, larger shrubs, or buildings. Plant lavender in the sunniest parts of your garden, ideally facing south where it can receive both morning and evening light. Avoid putting lavender too close to taller plants.
Choosing the Wrong Variety for Your Climate
In spite of its Mediterranean roots, lavender can grow in USDA zones 4-10. However, some types of lavender are quite frost sensitive, while others can’t handle the heat and humidity. In order to maximize your flower harvests and longevity of the planting, you need to select the right cultivar for your climates.
Big box garden stores often trick gardeners by selling varieties that aren’t necessarily adapted to the local region. For example, you can purchase French lavenders in New England nurseries, but they will die as soon as frost hits (unless they are grown in pots and brought indoors for the winter).
Classic English lavenders are remarkably frost tolerant, but when planted in hot, southern climates they can become susceptible to a range of diseases. On the other hand, fluffy-flowered Spanish lavenders are only hardy down to about 20°F and won’t overwinter in cold northern zones.
How to Avoid It
Choosing the right lavender variety can be a bit difficult due to the differences in rainfall, soils, microclimates, and temperature variations of different areas. Pay careful attention to why you are growing the lavender (ornamental, herbal/culinary, bouquet, or fragrance uses) and how much effort you want to dedicate to protecting it from winter weather.
Visit a local nursery that carries regionally-adapted Reference our ultimate guide to Lavender Varieties: 31 Different Types of Lavender Cultivars. When in doubt, Lavandin hybrids like ‘Provence’ and ‘Grosso’ are the most widely adaptable cultivars to most regions in the U.S.. They also happen to have the most coveted fragrance!
Forgetting to Protect From Hard Frosts
During its woody dormant phase, some varieties of lavender can handle down to a frigid -20°F. Others can only handle down to 20°F or 30°F. Lavender can be easily damaged or killed when left to fend for itself in extra cold weather. This is especially true if it hasn’t yet been pruned or gone dormant for the winter.
Northern gardeners often forget that this perennial is still a Mediterranean plant that can be quite fragile. If lavender isn’t brought indoors or protected by a frost blanket during the winter, it may die.
How to Avoid It
For ultra cold climates, choose only English or Lavandin varieties such as ‘Munstead’, ‘Anouk, or ‘Vera’. Be sure to properly prune back the foliage (without cutting the wood) in the fall to prepare the plants for dormancy.
If you are growing in pots, bring them indoors or protect them in a greenhouse or low tunnel. For more tender Spanish or French lavenders, mulch generously and use row cover to protect them overwinter. In the event of an unexpected cold snap while the plant still has foliage, cover your plants with a frost blanket.
Not Enough Space Between Plants
Nobody likes to be over-crowded in a small space. Most lavender plants typically need 2 to 4 feet of space in every direction. This ensures that they have enough sunlight, space to spread their roots, and airflow between their leaves.
Because lavender plants are often small at the time of transplanting, gardeners accidentally space them too close together. As they grow, they begin to compete with each other for nutrients, water, and sunlight. The lack of airflow between plants can also lead to more disease issues.
How to Avoid It
Be sure that lavender plants have at least 1-4 square feet of space, depending on the variety. Check the varietal tag and reference our Guide to 31 Different Types of Lavender Cultivars.
While they may look awkwardly spread out at the time of planting, rest assured that lavenders will grow into lush abundant bushes under the right conditions. If you are growing in a small space or container garden, opt for dwarf lavenders like ‘Thumbelina Leigh’, ‘Blue Cushion’, or ‘Little Lady’ that need only about 18” of space in each direction.
Most plants dislike being drowned in soggy soils, but lavender is especially finicky about soil moisture. These drought-tolerant plants aren’t used to a ton of moisture. In fact, lavender resents soggy conditions and actually prefers to dry out a bit between watering.
By standard logic, more water seems like it would promote more growth. Beginner lavender gardeners might find themselves dumping on the irrigation or planting lavender in high rainfall regions. This can lead to rotten roots, poor growth, and stunted plants.
How to Avoid It
Lavender needs the most water at the time of transplanting and 1-2 months after. Give the plant a deep soaking at planting and ensure that the water doesn’t pool up or create muddy soil. Then, water once every 1-3 weeks after checking the soil moisture with your finger. If your finger comes out clean and dry, it’s time for a moderate watering. Ensure that the soil is extremely well-drained by amending with peat moss, bark, sand, or vermiculite.
Once established, most growers only irrigate lavender once or twice per year. Spring rains are often enough to fuel early growth and extra irrigation is only needed during the hottest, driest months.
Not Checking for Fungal Diseases
Lavender is fairly immune to the disease in its native warm, dry climate. But if you’re growing in an extra humid or wet region, lavender is particularly susceptible to fungal diseases. While root rot is the most common lavender ailment, botrytis, “shab”, and phytophthora crown rot can also take hold of the herb.
Sometimes life takes over and you forget to go out and check on the garden. It’s easy to accidentally miss early signs of fungal pathogens like yellowing leaves, gray foliage, powdery growth, or droopy wilted plants. However, if these symptoms are caught early on, many lavender diseases can be easily managed organically.
How to Avoid It
Each time you go to harvest or prune lavender, give the plant a quick 1-minute inspection. Look near the base and crown of the plant, under the leaves, and around the stems. Remove any damaged areas and be sure that there are no major signs of disease spreading.
Poorly drained clay soils can make the situation even worse, so it’s essential to combine disease scouting with proper soil management practices that keep water flowing through your lavender’s root zone.
Forgetting to “Deadhead” Old Flowers
Like many ornamental flowers, lavender will keep cranking out new blossoms as long as the old, expired ones are removed. This is done through a process called deadheading. It should be done regluarly, regardless of the type of lavender you have in your garden.
Newer herb growers are pleasantly surprised to find out that lavender can bloom multiple times throughout the season. They often just let it flower and then leave the spent flowers on the plant to dry out and wither away.
How to Avoid It
If you want to get as many lavender flowers as possible, regularly harvest your lavender. If you prefer to leave the flowers in the garden for the bees, just prune off expired stems once the flowers begin to dry. This can be part of your early spring pruning to encourage more delightfully perfumed blossoms.
The most under-rated gardening tip is raising plants based on their native habitat. Once we remember that lavender originated in sunny, warm, dry, and rocky regions of the Mediterranean, we can understand so much about what the plant will prefer in our gardens.
If you want to avoid the most common pitfalls of growing lavender, remember to:
- Ensure the soil is very well drained.
- Do this by amending with bark, gravel, peat moss, or coco coir.
- Plant in full sunshine (at least 8 hours per day).
- Prune at least once per year in the spring after the first blooms.
- Only prune green lavender stems and never cut into the woody base.
- Provide 2-4 feet of space between plants.
- Research the best lavender varieties for your region.
- Regularly harvest or remove old flowers to encourage new blooms.
May your summers be filled with colorful floral abundance of beautiful lavender plants, and I hope you avoid any and all of these common lavender gardening mistakes!