Lavenders become progressively more woody as the plant matures. If you do not prune your lavender every year, the rate at which the Lavenders becomes woody will increase. Pruning 1/3 of the green growth every spring will slow down the rate at which lavender becomes woody, improves blooms and extends its life.
Prevention is better then cure when it comes to the problem woody lavenders. You simply cannot rejuvenate a woody old plant into a nicely shaped lavender that produces an abundance of flowers.
However you can take cutting of the plant and propagate the lavender quite easily rather then just remove the redundant lavender and buy replacements.
Read on to learn the steps to take to prevent lavenders becoming woody too quickly. And how to take cuttings from woody plants to produce new lavenders that are capable of flowering.
What Causes Woody Lavender?
Lavenders simply become progressively more woody as they mature starting at the base of the plant. You cannot stop this process entirely but you can slow it down and thus extend the life and flowering prospects of each lavender plant.
This formation of woody material is why it is so important to prune and care for lavenders annually.
The wood of lavender is particularly weak and it is vulnerable to splitting or coming apart if there is weight bearing down on it from snow, or accidental impacts from say a football landing on it or your pet dog deciding that it is a comfortable place to lay down and take a nap! (This happened to me).
Unfortunately once the wood has split it does not usually regrow nor will flowering stems be produced (flowers only appear on green growth).
The formation of wood will take away from the lavenders shape and appearance so it is important to now how to prevent wood forming which will help prolong the life and increase the flower yield of the lavender.
How to Prevent Woody Lavender
Lavenders need to be cultivated with good care and significant pruning in the spring and a light prune in the fall to prepare the lavender for winter.
Ideally lavenders should be pruned to form a robust, dense mound shape as this will:
- Resist snow, ice and water from getting into the lavender and rot the wood which will weaken it further.
- A mound shape will help deflect snowfall from forming and therefore putting pressure on the relatively weak lavender wood.
- A rounded mound is also the most effective shape for producing the most blooms.
By cutting back the green growth of the lavender by a third each year, you are essentially pollarding the shrub, much in the same way that foresters pollard trees. This process will significantly extend the life of the plant (if done correctly) as you essentially keep the shrub in an immature state so it can carry on producing flowers for many years.
- The correct time to prune your lavender is in the early spring when green leaves are starting to appear at the base.
- Remove approximately one third of the green growth with a sharp pair of pruners. Remember you are aiming for a mound appearance to make the lavender more robust and resilient to weather.
- Ideally prune the lavender in the morning as this is when the oils are most concentrated and therefore you can make use of the fragrant foliage.
- In late summer as the flowers have faded, you can prune the lavender again in order to neaten up the appearance and to maintain the optimal shape before fall and winter.
- The most important rule of lavender pruning is to never cut back into the woody growth as the wood will not rejuvenate or produce new growth that will bloom. Only prune green growth.
Follow these easy steps and you will slow down the woody growth of lavender, extend its life significantly and you lavender will be far less susceptible to winter damage.
For a visual guide of how to do this check out this YouTube tutorial:
Propagating Lavender from Woody Plants
Once a lavender has become woody and lacking in blooms, it is difficult to restore it to a plant that has a high flower and oil yield.
However, fortunately lavender is very easy to propagate, so you can take several cuttings from a mature woody plant and produce many other ‘new’ plants, which is significantly cheaper then buying new plants and its is rather gratifying to raise a plant from cutting to maturity.
- The best time to take cuttings for propagating is in the summer on a non flowering shoot.
- Take a cutting of soft green healthy looking growth (without any flower buds on it) of approximately 4 inches long.
- Delicately remove the leaves of the bottom two inches of the cutting with a sterile knife or fine scissors.
- Prepare a pot with about 70% potting compost and 30% sand or grit. (Lavenders need good drainage).
- Opinion is generally divided on this but I personally have seen a higher success rate by dipping the bottom tip of the cutting into hormone rooting powder which will stimulate root growth, although lavender propagation is feasible without rooting powder (although I would take some more cuttings to compensate).
- Plant the bottom 2 inches of the cutting into the soil and firm the soil around it to provide support.
- Keep the soil slightly moist but not wet and mist the leaves with a sprayer and move the pot into a warm place.
- With climates that are particularly arid, placing a clear drinks bottle (that has been cut at the bottom) will create a more humid micro climate whilst the roots are developing. Mature lavenders dislike humidity but with cuttings, some moisture in the air is required so that they don’t dry out and die before the roots have established.
- Roots will establish after 4-6 weeks at which point you can transplant the lavender to either a larger pot or into your garden.
Take a look at this tutorial for a good visual guide:
By taking cuttings and propitiating lavender you can salvage new plants from the old woody plant for practically no cost.
Take several cuttings because some cuttings may not develop even in ideal conditions, but typically most cuttings will develop into plants with the right care.
Just remember that you will need to prune lavenders every year to stop the formation of wood increasing too quickly from the base. If you take care of your lavender with the right soil conditions (see my article ‘What soil do Lavenders like‘) and the appropriate care then they can live over 10 years, producing quality blooms, oil and fragrance every season.
- Lavenders become more woody as they mature. Woody lavenders become damaged more easily, produce less flowers and often become misshapen.
- Prevention is better the cure with woody lavenders. To slow down the formation of wood it is essential to prune lavenders back every year, ideally, once in the spring and a trim in the late summer to remove spent flowers and their stems.
- Regular pruning extends the life of the lavender, maintains an attractive shape and encourages new growth to produce more flowers.
- Prune back about a third of new growth. The goal of pruning should be to form a robust, dense mound shape that resist damage from weather and to stimulate blooms.
- If your lavender has already become woody there is little you can do to revive the plant.
- Taking cuttings for propagation can be a great way to produce new plants from a old woody lavender, so that you can start fresh with healthy plants and prevent them from becoming woody as they mature, with regular pruning.