Probably the easiest grown plants for sunny, well drained sites, lavenders are loved by gardeners and now with the right selection it is possible to enjoy them all summer long.
Lavender is evocative of warm summer days filled with heady scents.
Lavender (Lavandula) is, of course, an easy to grow, evergreen shrub that produces masses of beautifully scented flowers above green or silvery-grey foliage. This drought-tolerant plant thrives in a sunny border, container, herb or gravel gardens.
It was once considered only as a high summer addition to the garden but more recent introductions offer the chance to extend the joy of having their serene spectacle in your garden over a longer season.
Some lavenders have great presence as architectural specimens, most are good for low hedging while of course all are wonderful for bees.
Lavender is best planted between April and May as the soil is warming up. It thrives in any poor or moderately fertile, free draining soils in full sun, and is ideal for chalky or alkaline soils.
On heavier soils, like clay and clay loam, lavender tends to be fairly short-lived, becoming woody at the base. To prolong the life of your lavender on heavier soil, add organic matter and gravel to improve the drainage and plant on a mound. If growing as a hedge, plant on a ridge to keep the base of the plants out of wet soil.
All hardy lavenders are in full bloom for about a month. The dark purple varieties appear to flower for longer as the richly coloured calyces are visible immediately the spikes begin to swell- and still hold colour when the flowers have faded.
Lavenders to start summer
If you are looking for an early blooming variety there is nothing to surpass L.angustifolia ‘Ashdown Forest’, a bushy cultivar with its sharply scented pale blooms.
As the lavender season progresses through late June and into July more cultivars begin to reach their peak including L.agustifolia ‘Hidcote’ –a compact form of the popular English lavender, named after plantsman Laurence Johnston’s famous arts and crafts garden in Gloucestershire. It produces dense spikes of fragrant, deep violet summer flowers above slender, aromatic, silvery-grey leaves. It is possibly the best lavender for edging paths and borders and the aromatic foliage perfumes the air if you brush against it. It also works well in a gravel garden, or clipped into a formal sphere for a contemporary look.
Another option for this time of the year is Langustifolia ‘Miss Dawnderry’ , an intensely dark purple lavender known as a ‘Super Blue’, with a beautiful swaying and fluid movement in a light breeze. The flowers dry darker and the slender stems when bunched produce a proportionally larger head, than any other angustifolia.
If fragrance is a priority then nothing really comperes to Langustifolia ‘Maillette’ -the world’s most widely grown angustifolia for oil. Long mid-purple flowers above grey foliage. Very highly scented. The flowerheads of ‘Maillette’ are packed full of tiny plum to lilac star-shaped flowers, and are barrel-shaped rather than spiked.
Lavenders into the high season
Throughout July, Langustifolia ‘Betty’s Blue’ is a wonderful accent plant with its large, deep violet-blue flowers atop erect stems that do not splay, It is a compact and tidy variety that forms attractive domes in the garden. Sweetly fragrant and reliable, it is also a great lavender for drying.
From July one of the first of the late bloomers is L.x intermedia ‘Olympia.
These consistently popular tall tough lavenders have great presence as specimens or hedges. Their unsurpassed scent and colour are evocative of high summer. Hardy to at least -15°C, they will cope with most British weather.
Lavender final flowerers
As July falls in August L.intermedia ‘Provence’ displays highly flagrant pale purple flowers which fit in so well with its name. A delightful variation on Lavender ‘Grosso’ named for the province in southern France where ‘Lavandin’ is grown by the acre to supply the perfume industry. At three feet tall it is one of the tallest varieties, and its long, silver-grey spikes lined with mauve blooms make first-rate cut flowers. Last to flower often in autumn are the so-called Dutch lavenders, usually distinguished for their silver foliage. L.intermedia’ Fragrant Memories’ is probably the best. It overwinters well, and has very long flower spikes of mid-lilac blue, making it a good cutting variety.
Lavenders should be pruned every year to keep them compact. On established plants use secateurs to remove flower stalks and about one inch of the current year’s growth, making sure that some green growth remains. At RHS Wisley, pruning is undertaken in late summer after flowering, although spring pruning is sometimes recommended. Lavender does not break readily from old wood and neglected specimens are best replaced.
You can easily make more lavender by taking softwood or semi-ripe cuttings from young plants in early summer and hardwood cuttings from new growth after flowering in late autumn.
Growing in pots
Lavender can be grown in large pots, using multipurpose or loam-based compost such as John Innes No 3, with some extra coarse grit, up to 30per-cent by volume, to improve the drainage, and some controlled release fertiliser granules.
Ensure that the compost is regularly watered in summer, but for improved cold tolerance, kept on the dry side during winter by standing in a cold greenhouse or in the rain shadow of walls.
Most lavender can be grown in pots, but it is ideal for tender types - H3 (half hardy) or H2 (tender), such as L. canariensis, L. dentata var. dentata ‘Royal Crown’ AGM.
The best for bees
A study at the University of Sussex found that two late blooming varieties were particularly valuable to bees L.x intermedia ‘Edelweiss” and ‘Gros Bleu’ were the cultivars most visited by all bees, most of which were bumblebees.