One of the most popular cottage garden or floral plants, lavender is a colorful, aromatic, long lasting plant. Just at home in the flower bed as it is in the herb garden, these delicate looking plants are pleasingly long lasting and resilient.
Knowing how to care for lavender (Lavandula) helps you to get the most from these attractive plants. An essential part of knowing how to care for these plants is pruning lavender correctly. Whether this is done for maintenance or to harvest the flowers for drying, decoration or making aromatic oils, pruning lavender correctly is an essential skill to master.
This guide to pruning lavender not only takes you through everything that you need to know, it also explains just how and when to prune the plants at different stages of their life. This means that your mature specimens can be just as full and floral as younger plants.
These are colorful, fragrant plants.
How Lavender Plants Grow
Before pruning lavender plants, it is important to understand how these plants grow and develop. This information helps you to correctly prune the plant to promote healthy growth, flowering and longevity.
Most lavandula plants are classified as semi-shrubs or subshrubs. This means that, because they produce lots of soft, green growth, they look like a perennial plant. However, if you look at the base of the plant, you will notice the stems becoming woody.
As the plants grow, at the center of the plant, a mound of semi-shrub wood forms. One goal of pruning lavender is to slow down the transformation from a perennial-looking plant with lots of soft, green growth to a woody specimen.
Unlike true shrubs and trees, Lavandula wood does not rejuvenate. This means that the old woody sections do not produce new shoots. Any shoots that do form are spaced out, giving the plant a sparse, almost empty appearance.
Not only is Lavandula wood unproductive, it is also weak. This means that it is prone to splitting in snowy or icy conditions. The wood is also prone to developing rot.
Lavandula plants have a shallow root system. This means that the plants are more prone to developing rot and suffering from over-watering related problems. Many of these issues, if left unamended, can lead to the untimely death of the plant.
Regularly pruning lavender encourages root growth. Pruning lavender in the fall forces the plant to send energy into its root system for storage, this strengthens the root system and helps to prolong the lifespan of the plant.
Now that you know why pruning lavender is so important, it is time to learn how to prune these attractive specimens.
When to Prune your Plants
Pruning lavender is best done after flowering has finished for the year.
These are forgiving plants, while they do tolerate a little cutting back other times of year, this is best kept to a minimum.
Pruning lavender at the wrong time of year can deter flowering or slow down growth. These plants set flowers on the current year’s stems.
Cutting the plants back in early or even mid spring can be done without doing too much harm as long as you are careful. In fact, many growers like to prune the plants in early spring to delay flowering.
Pruning lavender in early spring is also a good time to remove any dead portions of the plant and shorten the growth to the buds. This leads to a healthier, fuller and more productive plant developing.
You can prune the plants again in late summer or early fall, once flowering has finished for the year. Pruning lavender at this point in the year, just before the first frosts of fall, helps to promote good air circulation and prevent issues such as powdery mildew and rot from developing.
Hard prune the plants after the flowers have faded for the year.
Pruning lavender plants twice a year may seem like a lot of work, but it needn’t be too time consuming and is really beneficial to the overall health of the plant.
How to Prune Your Plants
Pruning lavender, like any other plant, can seem a daunting prospect if you have never done it before. However, as you will see from our guide, it is actually a pleasingly straightforward process.
You will need:
- Pruning shears,
- Bypass pruners,
- Lavender plants
If you do not own a set of shears or pruners, our guide to the best garden scissors is packed full of useful information to help you source the best product.
Make sure that your tools are clean and sharp before starting. Always clean your tools before or after use. This helps to prevent the accidental transmission of disease or infestation from one plant to another.
Clean and sharpen your tools before and after use.
If you have sensitive skin you may also want to wear a pair of work gloves.
Once you have everything that you need, it is time to prune your plants. How you prune the plants varies depending on the time of year and age of the plant.
Spring Pruning Lavender
A spring prune minimizes the development of woody stems. Instead it encourages fresh growth to form. In early spring examine each stem. You should see a woody base set below the leafy, softer section. Older plants typically have more wood than younger specimens.
Use a sharp, clean secateurs to cut 2 to 3 inches above the woody base, cutting into the softer, leafy section. Do not cut into the wood.
If it is easier, you can cut handfuls away at a time. While less precise, this is easier than cutting each stem individually. Aim to prune the plant into a pleasing, rounded shape.
As you prune, completely remove any dead, damaged or diseased branches.
To cut the plants back for winter, use a garden scissors or shears to shape the plant into a tidy mound. Aim to give the plant a pleasing shape and structure.
Prune before the winter frosts arrive.
In warmer climates, evergreen types retain their leaves all year round. These can be pruned in either late summer or early fall. Hardier types can be pruned slightly later in the fall. Some gardeners like to leave some of the faded flowers on the plant to provide a source of winter seeds for garden birds.
How to Prune Young Plants
You can start pruning lavender plants when they are young. At this stage the plants need little more than a light prune to encourage them to produce lots of roots and branching stems. This, in turn, encourages the plants to develop into a pleasing, rounded shape. A light trim when the plants are young also helps to prevent them from becoming leggy in later years.
If you have grown the plants from seed or cuttings, in the first year you need only pinch out the new growth tips. This encourages the plants to form into a thick, bushy shape.
Pinching off new growth tips encourages young plants to branch out, forming into a good, dense shape. Pinching out young plants also encourages them to set out lots of blooming growth when they are mature.
While it may seem daunting, do not put off pruning and shaping young plants. The woody growth that mature specimens produce is more difficult to shape than the soft, green growth of young plants.
Prune young plants to encourage a bushy growth habit.
How to Prune Established Plants
Once established, Lavandula plants are more tolerant of a heavy prune than younger specimens.
You can safely prune established plants back by at least a third in late summer or early fall, after flowering has finished for the year.
If planted in full sun, these plants enjoy a vigorous growth habit. This can cause them to become untidy. A regular hard prune every fall gives you chance to reform or reshape the plants, returning them to their neat, green mound shape
To prune established plants you can use either hand pruners or compact shears such as Fiskars Micro-Tip Pruning Shears. While larger shears are less precise, if you have a hedge, living fence or long line of plants, they are much quicker than hand pruners.
How to Prune Older Plants
Like established specimens, older plants tolerate a heavy prune in the early fall, once flowering has finished. When pruning older plants, do not cut down to the leafless wood.
Before you start to prune your more mature plants, take the time to inspect them. Try to find the spot where the soft green growth meets the woody stem. Prune and shape only the soft green growth.
While you can’t rejuvenate the plants by cutting into the old wood, you are able to rejuvenate the plants by cutting them back to a point just above the wood. A good rule of thumb is to count up the stem to the third node, a raised bump from which leaves grow, above the woody part.
Cut just above this node with sharp garden scissors. This encourages all 3 remaining nodes to produce leaves and flowers the following spring.
When pruning lavender in late summer you can remove around a third of the soft growth. Prune to maintain a rounded shape.
Do not prune older plants too hard in the fall. As you prune, avoid cutting too close to the woody base of the plant. Exposing too much of the plant may lead to it struggling to survive prolonged exposure to periods of cold weather.
If you are worried that the plants are too exposed, cover them with an Agribon Floating Row Frost Blanket. A permeable cover, the blanket allows light and moisture to penetrate down to the soil whilst protecting sensitive plants from the effects of cold winter temperatures.
If your garden experiences cold winters, mature plants can be trimmed lightly after flowering and pruned more fully in the spring. This protects them from the potentially harmful effects of the cold winter weather.
How to Prune Different Types of Lavandula
While the pruning lavender tips outlined above can be applied to all types of Lavandula plant, the different cultivars also have some specific requirements. English lavender is the hardiest variety. It also requires the most pruning. In contrast, French and Spanish types need more gentle handling.
Hardy, English and hybrid types can be cut back to about 9 inches or 22 cm above the ground. Aim to cut above groups of new shoots. Do not prune away these new shoots.
Frost hardy types tend to flower longer than more delicate cultivars. These can be pruned lightly, deadheaded and tidied up after the first flowering. They can then be hard pruned in late summer or early fall, no later than mid-September. More tender types are best deadheaded during the summer months and only occasionally cut back to new growth if they grow out of shape.
Different varieties have slightly different pruning needs.
English cultivars (Lavandula angustifolia) are amongst the most popular and resilient. They include the reliable Munstead and Hidcote varieties.
Lavandula angustifolia plants produce single leafless stems on which sit compact floral spikes. These plants are typically low growing, forming in a compact, mounded shape.
Flowering in late spring or early summer, depending on the growing conditions, prune Lavandula angustifolia plants lightly after the first flowering has finished. This encourages a second floral display to form in late summer.
As the flowers fade, a full prune can be conducted in late August or early September. This prepares the plant for the winter period and also encourages flowering the following spring.
Lavandin x intermedia
A hybrid of the English and Spike or Portuguese (Lavandula latifolia) types, there are numerous different varieties such as Provence, Giant Hidcote and Grosso.
Producing branching stems that are longer than those of Lavandula angustifolia, these plants are an increasingly popular choice for the flower or pollinator garden. The floral spikes also tend to be longer than English floral spikes, tapering gracefully as they reach the tip. Larger than Lavandula angustifolia plants, Lavandin x intermedia plants form in a distinctive mounded shape.
Lavandin x intermedia plants produce long stems that fan out from the center. Flowering during mid or late summer, once flowering has concluded, prune heavily to encourage the plant to prepare for winter. You may need to prune away as much as half of the plant’s size because of its long stems.
Spanish or French Lavender
Also known as Lavandula stoechas, these plants are the least hardy of all the different varieties. Flowering in early spring, Spanish and French cultivars produce short, full floral spikes with open petals at the top.
Delicate plants, prune as lightly as possible after the first flush of flowers has started to fade. Do not prune too close to the base. Simply deadhead spent flowers and lightly shape the plant.
Delicate varieties do not tolerate as much pruning as hardier types.
You can continue to prune these delicate plants lightly in the same manner throughout the growing season. A slightly more vigorous pruning can be conducted in late August to help prepare the plant for winter. It also encourages a full plant to form next spring.
Can I Rejuvenate Woody Plants?
Old plants, or those that have been neglected, can become overly woody. The normal advice is to simply dig up and replace them with younger, more productive plants.
However you can also try pruning them. Cutting into old wood can, in some circumstances, renovate or rejuvenate the plants. This only works on plants that are still producing new growth nodes. Make sure that these are visible below the cutting point. If you cut away all of the still viable growth nodes the plant is unlikely to recover.
Aiming to rejuvenate old, woody plants is a risk. To protect against failure, take some semi-ripe cuttings and propagate these. If your mature specimen fails to produce new growth, dig it up and replace with the newly propagated plants.
What Not to Do
Never prune away the woody stems or remove more foliage than is absolutely necessary. Heavily pruning lavender can stress the plant. This can slow growth and deter flowering. In the worst cases, too much stress can even kill the plant.
Never prune your plants any later than the end of August or early September. Pruning lavender encourages new growth to form. Pruning lavender too late in the year leaves the plants open to the danger of being damaged or killed by the cold winter weather, weakening the plant.
If you forget to prune the plants in late summer, wait for winter to pass and prune the following spring.
Regularly pruning lavender plants helps to keep them healthy. If you neglect to prune these plants they will get large and woody. As the branches grow, hooks that trap water form. These can cause rot or enable frost to strike and damage the plant.
Water trapped in the hooks may also free during the winter months, splitting the woody plants, finally woody, sprawling plants are vulnerable to damage from snow loads. Surprisingly heavy, these can damage or break the plants.
Popular with both gardeners and pollinators, pruning lavender plants helps to promote healthy growth and lots of flowers.
Do not be afraid to prune the plants. Without pruning lavender the plants quickly become woody and ragged. Annually pruning lavender helps the plants to stay productive and healthy. It also prolongs their lifespan. With the right care the plants can last for up to 20 years.
Lavender’s silver-green foliage and scented flowers has helped to make it a popular summer cottage or cut flower garden plant. In addition to the more common purple flowers, white and pink flowering types are also available. All are popular with pollinators.
In the right conditions, lavender is easy to grow and maintain. An essential part of learning how to grow these plants, pruning lavender enables you to correctly care for them, helping to prolong their lifespan and maximize the annual floral display.