Further Information about Lavender Hedging
How to grow Lavender plants
Lavender plants are easy to grow provided they have the right conditions, these are Mediterranean plants so enjoy full sun and good drainage. They will grow in all soil types that don’t suffer from winter wet (in which case you may be better choosing one of our hedges for wet soil).
Very acidic soils (where Rhododendrons grow very well) will benefit from having some lime (around a handful for each square metre) added to a site where you intend to grow lavender plants as they prefer neutral to alkaline soil conditions.
If you soil is on the heavy side, there ways of improving it so lavenders will be successful. You could grow them in raised beds that will drain more freely, otherwise incorporate some grit or coarse horticultural shard sand to open up your soil so that excess winter wet can drain. Lavenders are very hardy plants, problems occurring over the Winter are almost certainly a result of winter wet rather than Winter cold. When planting it can pay to create some shallow mounds and plant in these as they will be well above the water table.
Lavender plants grown in soil with reliable drainage will usually have a life span of at least twice those in heavier and more unsuitable growing conditions.
If the soil is poor you may like to add a little garden compost or well-rotted manure to improve it but do be sparing, and mix it well with the surrounding soil.
Lavender plants may of course be grown in pots and can make a beautiful and fragrant addition to a patio or terrace. Again, good drainage is required so do ensure the pot has generous drainage holes in the base. Ideally choose a good size pot of at least 30cm across or larger and fill with an equal mix of soilless compost, John Innes no 2 or 3 compost and finally coarse grit so that the pot drains quite sharply during the Winter.
Lavender plants need regular watering to begin with while they establish (which should be quite quickly), try to water the soil and not the plants as they dislike wet foliage and once they are growing away well, stop watering altogether (The only exception being Lavenders grown in pots which will need regular watering during the growing season).
While newly planted Lavender will need watering while they establish, be careful no to overdo it so that the soil does not become saturated, a little water goes a long way. (And very wet soil can take a long time to dry out!)
Lavender plants are one of the few species that we do not recommend mulching, while most garden and hedging plants appreciate the conserved moisture and a cool root run, Lavender plants dislike it and prefer the heat and dryness, mulching can cause the foliage to stay wet and be the focus of disease later. The key to growing healthy Lavender is to keep good air flow, full sun and dry.
Using Lavender plants to grow a hedge.
A Lavender hedge makes a beautiful addition to a sunny garden, especially along a path or surrounding a seating area where the intoxicating scent may be appreciated.
The same principles above still apply, be sure that the drainage is good, improving it if necessary. For a dense continuous hedge, we would recommend using 3-5 plants per metre using the higher number of plants for those in smaller pots sizes and the smaller growing varieties of Lavender plants.
You can of course plant a little further apart in which case the larger varieties will grow together over time and with a little more patience, while the smaller types will grow into a series of ‘bumps’ which can also look very effective.
If you choose Lavender as a hedge bordering a flower bed or vegetable patch, try not to let any luxuriant growth on the plants within the bed sprawl over the Lavender plants. This can cause the damp shady conditions underneath which lavenders so dislike. When you come to cut these plants back in Autumn you may be very likely to reveal a dead section of Lavender underneath. Instead keep the plants trimmed back if necessary, try and keep a 30cm ‘exclusion zone’ around the Lavender plants so they can feel the sun on their faces and have good airflow so the foliage stays dry.
Pruning Lavender plants and hedges.
Unless you are going to treat your Lavender plants as a short-term project to be replaced in a few years, you will need to prune them. Unpruned Lavender plants can quickly become straggly and leggy, liable to sprawl and open up to reveal unsightly gnarled looking branches that bear few flowers. Once this stage is reached they can be very difficult to rejuvenate as they seldom respond to very hard pruning.
Avoiding this sorry state is fortunately simple, once the flowers on the plants or hedge start to fade, cut them back by at least one third, preferably more (so removing far more than just the flower spikes) and do this as early as you can bear to. You can be as hard as you like provided that there are signs of young new shoots underneath where you are cutting. (You will only kill the plant if there is nothing but bare wood underneath)
While this can appear quite harsh to begin with the plants will quickly produce a healthy re growth and by mid-Autumn they should be clothed with healthy new growth that will set them nicely for the Winter while ensuring masses of flowers the following year.
For the later flowering intermedia type of Lavender plants, it is often worth sacrificing some of the flowers to ensure the pruning is carried out in late summer giving them time to re grow. If you really cannot bear to lose this late colour and it is very late in the season, then it is better just to dead head them. Harder pruning in late Autumn with no protective regrowth to insulate from the Winter cold will cause damage. Instead give them the rest of their annual haircut in late spring when the weather has warmed up and they are starting to make growth. New shoots that will bear the current seasons flowers will appear shortly after.
Feeding Lavender plants and hedges.
Generally speaking, Lavender plants do not need much in the way of feeding, if you add more than a small amount of general fertiliser they will make masses of leafy growth and be likely to flop just as the flower spikes start to lengthen, spoiling the effect. Instead we would recommend nothing more than a modest feed with a high potash fertiliser in late Spring.
As already mentioned, Lavender plants do not benefit from mulching. Better to leave the soil bare and dry – the conditions they love!
When to harvest Lavender.
Customers often ask us when the correct time is to harvest the flowers on their Lavender plants. This depends on what you plan to use the flowers for.
If you plan to use the Lavender for culinary purposes, we would recommend the flowers are harvested when the buds show full colour but before the flowers begin to open. They may be added to recipes fresh or dried for use later on.
For all other uses, for example pot pourri and dried flower arrangements it is better to wait until the flowers begin to open but before they are fully developed. The flowers should be cut and hung upside down in a cool and airy dark room until fully dried and ready for use.
Pests and diseases of Lavender plants
The good news is that Lavender plants suffer from very few pests and diseases. The familiar Lavender fragrance tends to repel most harmful insects. Problems with Lavender plants are chiefly limited to fungal and root diseases and these are almost always a symptom of either poor drainage, over watering or from the plants having persistently wet foliage. If these conditions can be avoided your Lavender plants should be problem free.