Lavender is without doubt one of the most popular of all hardy shrubs, and why not? Tolerant of drought, heat, poor soils and most pests and diseases, not only does will lavender flower its heart out, it is a fantastic source of nectar for pollinating insects!
However, you can't just plant lavender anywhere and they can easily be killed by too much kindness.
So, just how do you successfully plant lavender?
Lavenders flourish best in dry, well-drained, sandy or gravelly soils in full sun. All lavender species need little or no fertilizer and good air circulation. This is particularly important in areas of high humidity as root rot due to fungus infection can be a problem. Avoid organic mulches as this can trap moisture around the plants' bases, again encouraging root rot. Instead, use pea gravel, decomposed granite, or sand instead.
How to take cuttings of lavender?
Taking cuttings from lavender is surprisingly very easy so long as you take them at the right time of year. Luckily you will get two bites of the cherry regarding this as you can take lavender cuttings either in the spring - just before the plant comes into flower, or in the autumn around august time.
Lavender has been propagated by cuttings for thousands of years so I will keep the technique 'old school' because I know this way works. Using 3 inch terracotta pots, fill with a good quality compost such as John Innes 'Seed and Cutting' or you can make your own by mix approximately 3 parts peat moss with 1 part horticultural grit or vermiculite. The most important thing here is that the compost is well drained. Dampen the mixture then poke a small hole about 1 to 1½ inches deep into the soil into which you will plant your 'freshly -cut' cuttings.
How to take lavender cuttings
Using a sharp, sterilised knife or secateurs, cut a small branch off the lower half of the plant that is about 3-5 inches long. Make sure that the branch is soft and not woody. Strip the bottom half of the cutting of leaves, place in the hole in soil that you prepared earlier then close the hole with soil. There is no need to use rooting hormones on lavender cutting, but no harm will be done if you are addicted to using it.
Water your new plant thoroughly after planting. For the first couple of weeks keep the soil damp, but then water less frequently. At this point water when the soil begins to get dry, but before the plant displays any distress. Too much water will kill your new lavender plant. When attempting to propagate lavender, this is the most common mistake.
After about 6 weeks you can move your new lavender plant to a larger pot or into the ground. If planting lavender in the ground, dig the hole about 1 ft wide and about 8 inches (20 cm) deep. Prepare the soil by mixing sand, peat moss or compost, and your native soil. It's most important that the soil drain very well. Fill the hole far enough with your soil mixture that the plant will be at the proper level when the hole is filled the rest of the way. Before filling add a teaspoon full of bone meal or another slow release fertilizer. After removing the plant from the small pot, pour a small amount of root stimulator on the roots, then cover with soil.
When do you prune back lavender?
Get it right and next year your plants will be vigorous and full of soft, succulent, and healthy growth. Make sure you get it right by pruning your lavender plants back in August.
Why August? Because August is the hottest month of the year - at least is is where I live. And the reason why this is important is because the plant will be naturally dormant during this time, but ready of a second seasons flush of growth during the on-coming autumn.
Of course if you don't live in a European climate and August is not the hottest month of your year then I am sure you will know which one it is for your location and therefore prune back in that month.
How to prune back lavender
Lavandula angustifolia by cutting it back by two thirds of its overall height, you can even cut into the bare wood, if needed. New shoots will quickly appear at the base of the bush and these will have enough time to grow and harden up before winter comes.
This pruning regime will keep an English lavender plant compact for many years and a well-pruned plant can last for twenty years or more without becoming woody.
You can give English lavender another tidy in April to delay flowering time. This is particularly useful close to roses, because the main flush of lavender follows the June flush of roses.
With less hardy lavender varieties you never cut back hard into the bare wood. Shape them with shears in late August, aiming for a rounded mound of foliage.
Lavender stoechas varieties have a flag-like petals at the top of each thick flower spike and they are often labelled Spanish or French lavenders. They flower in much earlier, often in May, but are much less hardy than most garden lavenders. Give them a very gentle trim after the first flush of flowers has faded, often in late June, but never cut them back hard as this can kill them off.
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