How And When To Prune Lavender Plants

Tools Needed

For pruning lavender, you'll need a few essential tools:

• Hand Pruners: Sharp, clean hand pruners are ideal for making precise cuts on smaller stems.
• Hedge Shears: Useful for shaping and trimming larger lavender bushes.
• Gloves: Protect your hands from scratches and provide a better grip on the tools.

Cleaning your tools before pruning lavender is essential to prevent the spread of disease and ensure clean, healthy cuts.

1. Deadheading Lavender Blooms

Deadheading spent flowers off the lavender serves to maintain the appearance of the plant but also enhances new growth. Lavender will continue to flower with or without deadheading.

However, taking off old flowers can help the plant not expend energy in the production of seeds but create more flowers.

Remove the withered flowers using clean, sharp scissors or pruners, just above the leaves. Deadheading your lavender from time to time in the blooming season. It's also good for avoiding plant diseases or pests sitting on decaying flowers.

2. Prune Lavender Late in the Season

Lavenders should be pruned back after their main flowering, which generally occurs late in the summer. This way, pruning after flowering keeps the shape of a plant intact and allows new growth.

If lavenders are not cut back, they start developing wood and tend to grow somewhat overgrown, which negatively affects the health and blooming of the shrub in subsequent years.

When flowering has finished, cut the flowered stems back and about one-third of the green growth back yet again; this is to ensure it does not cut into the old wood, which could contribute to new growth failing to break. 

3. Spring Pruning for Maintenance

Spring is a good time to give your lavender a light prune before the growing season starts. This form of pruning maintains the size of the plant and helps remove dead and damaged stems. It is also what keeps the plant healthy and prevents it from becoming leggy.

Prune any dead branches off in early spring before new growth starts, and lightly tip back the tips of the plant. Be very careful not to cut too far into any woody portion of the stem. Pruning in spring sets up healthy growth and heavy blooming for the summer months.

4. Pruning to Prevent Woody Growth

Lavender becomes woody and sparse when left unpruned for some time. This makes it less attractive, and its capacity to flower will be lost. Regular pruning avoids this; thus, it keeps your lavender bushier and more productive over time.

Prune off approximately one-third of the plant's height at the end of each year's blooming and do not cut into the woody stems of the plant. Regular pruning will encourage new growth and prevent the plant from becoming straggly or leggy, which means it will remain healthy and full.

5. Prune Lavender to Shape Them

Pruning also helps the lavender to be in a neat, rounded shape, hence enhancing its appearance, promoting better aeration, and allowing proper penetration of light to its inside parts necessary for its healthy growth.

This well-shaped lavender plant will, therefore, offer more resistance to diseases and pests and produce much more flowers.

Immediately after the major flowering period, prune the plant into a consistent, rounded shape using sharp, clean scissors or shears. This helps to maintain compact and balanced growth. Shaping your lavender prevents sprawl growth, keeping it neat and tidy.

6. Lavender Pest Prevention: Lavender Beetles and Moths

While usually hardy, lavender is not immune to the rosemary beetle and moth larvae, the latter causing damage to the leaves and flowers.

Regular pruning usually keeps these few pests at bay by removing potential sites that favor breeding, in addition to allowing good air circulation around the plants. Prune regularly to remove dead leaves, which could house potential eggs from pests. 

Check for signs of larvae or beetles and immediately remove any infected stems. A well-cared-for lavender plant is more resistant to infestation with pests and remains healthy throughout the year.

Pruning lavender varies slightly depending on the type of lavender you are dealing with. Here's a general guide on how to prune different types of lavender:

Lavandula angustifolia (English lavender)

English lavender, known for varieties like 'Hidcote' and 'Munstead', features single, leafless stems adorned with compact spikes of blossoms. This type of lavender typically grows low to the ground and forms a tidy, mounded shape.

This variety typically blooms from late spring to early summer. To encourage a second flowering in late summer, it's best to lightly prune it just after its initial bloom.

This involves trimming off the spent flower spikes, which can stimulate new growth and potentially lead to another round of blossoms later in the season.

After the second flowering, which typically occurs in late summer, it's beneficial to perform a thorough pruning of English lavender. This involves removing spent flowers and any damaged stems.

This late August pruning helps prepare the plant for winter dormancy and promotes healthier growth with more blooms in the following spring.

Lavandula stoechas

Lavandula Stoeches, also known as French lavender or Spanish lavender, is the least hardy among lavender varieties, typically blooming early in spring. It features short, full flower spikes with open petals at the top, setting it apart from other lavender types.

Due to its delicate nature, it should be lightly pruned—avoiding cutting too close to the base—immediately after the first flowering. Subsequently, throughout the season, engage in gentle deadheading (removing spent flowers) and shaping to maintain its appearance.

Optionally, a slightly more vigorous pruning in late August can prepare the plant for winter and promote fuller growth in the following spring.

Hybrid Lavender

Hybrids of English and Portuguese lavender, known as Lavandula x intermedia or lavandins, come in various varieties such as 'Grosso', 'Provence', and 'Giant Hidcote'. These lavandins feature longer flower spikes with a graceful taper compared to English lavender.

They typically have a mounded shape and are larger, with long stems that often fan out from the center of the plant. Lavandins bloom from mid to late summer, so it's beneficial to perform a full pruning after the long blooming season to prepare them for winter.

Due to their longer stems, you may need to prune as much as half of the plant's size to maintain its health and shape.

The best time to prune lavender is just after it finishes flowering. This is typically around the end of the summer into early fall. Pruning too late in the season can cause plants to be more vulnerable to cold damage.

For optimal health, prune during dry days and early morning. The conditions allow cuts from pruning to form a callus faster. Thus, reducing the chance of plant diseases to attack the injured area of the plant.

Spring Pruning

Pruning your lavender plants in the spring will keep your lavender healthy. You can begin pruning when new growth commences, which is normally early to mid-spring.

Take some clean, sharp shears and cut back about one-third of the plant, focusing on removing any dead or damaged stems.

This encourages bushy growth and increases flowering. Be careful not to prune into the woody portion of the plant, as this area may not produce new growth. The plant then takes on a nice, mounded shape that allows for good airflow and deters disease.

Routine spring pruning prevents lavender from becoming leggy and maintains the plant's life span and full flowering color throughout the season.

Summer Pruning (After the Bloom)

Pruning in late summer or early fall is done right after the lavender has finished its cycle of blooming. This would, of course, be lighter as compared to spring pruning and would deal with mainly taking off the spent blooms and untidy growth.

You are, in effect, encouraging another flush of flowers and keeping the plant neat and bushy. Summer pruning prevents sprawling, which may otherwise give the plant an untidy appearance.

The process keeps the plant looking good, with better aeration within the body of the plant, hence the reduction of fungal diseases.

Since pruned lavender is more vulnerable to winter damage, stop pruning your lavender plants six weeks before the expected first frost date for your area.

Pruning First-Year Plants

Pruning first-year lavender plants is a bit more gentle to get them established and growing strong and healthy without shocking the young plant. During the first year much of your pruning will involve pinching back the tips of the plant rather than a full prune.

This will help the plant grow bushier and create a solid framework that will support further development in the following months.

When pinching back, only the top set of leaves or flower buds are removed, but this signals the plant to grow several new shoots. This early training makes the lavender plant more vigorous and opens it for heavier pruning the next years.

Fall Pruning

Any pruning in fall is optional and done with caution. Prune in the fall if you have to, doing a light trim to remove only the top couple of inches of growth. This should target spent blooms and straggly stems.

Early in the fall, pruning should be done so that the plant has adequate time to recover before winter sets in.

This will also be achieved with light pruning, which will allow the plant to retain its shape and clean over winter. Caution, however, should be practiced against doing this late in the season, as it may expose the plant to cold and frost damage.

The main purpose for pruning your plant in fall is to set it up for dormancy, but not to stress it. If in doubt, it is often better to wait until spring when heavier pruning can be undertaken.

While not essential, pruning lavender in the fall may lead to a need for another light trim in spring to refine the plant's appearance and remove any winter-damaged stems.

It's important to note that pruning in spring can potentially reduce flower production, so it's advisable to prune early before flower buds form.

Spring pruning should begin after new leaves start sprouting. Attempting to prune deciduous lavender plants before they leaf out is challenging and risks cutting into the woody parts of the plant.

• Regular Pruning: Regularly prune lavender each year to maintain its shape and prevent it from becoming too woody.
• Avoid Heavy Pruning: Never cut back into the old, woody stems, as lavender may not regenerate well from these parts.
• Sanitize Tools: Keep your pruning tools clean and sharp to prevent the spread of disease.
• Climate Considerations: In colder climates, avoid heavy fall pruning to prevent damage from winter weather. In milder climates, lavender can tolerate a bit more pruning.