No other garden plant captures our imagination quite like lavender. Perhaps it’s this silver-leaved, aromatic sub-shrub’s association with the sun-soaked landscape of the Mediterranean where sloping hillsides filled with neat ribbons of its intense violet-blue flowers are one of the joys of high summer. Or maybe it’s the plant’s oh-so-distinctive perfume, a scent associated with feelings of calm and tranquillity that’s the result of a natural plant alcohol known as linalool being released into the air. It is used in a wide range of hygiene and cosmetic products, and recent scientific research suggests that the mere smell of linalool exerts such a powerfully soothing effect that it could play a useful role in relieving anxiety in hospital patients prior to surgery.
That’s not all that lavender has to offer. This extraordinary plant is also known for its antifungal, antimicrobial, anti-oxidant and antispasmodic properties while its essential oil can be used topically to help treat burns, insect bites and wounds and avoid scarring. Even its dried leaves and flowers can be used as a natural insect and rodent repellent, the very practical reason behind the enduring popularity of those pretty pot-pourri bags of dried lavender traditionally placed in wardrobes and clothes drawers.
Meanwhile, in the kitchen, lavender’s pollinator-friendly, nectar-rich flower spikes, which come in shades of white, pale blue and pink as well as the traditional lavender-blue, have a long history of culinary use as a food flavouring for home-made ice-creams, biscuits, jams, soups, stews and salads. They also make great cut-flowers and can be easily dried for a long-lasting, pretty, scented display.
In the Irish garden, lavender makes an excellent, fast-growing, evergreen, wildlife-friendly low hedge. It also looks wonderful planted in a contemporary gravel garden alongside other sun-loving decorative species such as Russian sage (Perovskia) , verbascum, sedum, eryngium, verbena, origanum, dierama, stachys, cistus, santolina, artemisia, echinacea, phlomis and ornamental grasses such as stipa (Stipa tenuissima, Stipa calamagrostis and Stipa gigantea) , all of which relish the same sort of free-draining, warm, bright growing conditions. Alternatively, it looks right at home in a sunny, cottage-garden style border where it associates well with other enduring favourites such as roses, alliums and catmint, or in a pot or window box where it will liven up a container display while coping impressively well with a minimal watering regime.
Whatever you plump for, what’s vital is that this heat-loving, drought-tolerant Mediterranean native is given a hot, bright, open spot in full sun and a very free-draining, weed-free, not overly fertile, neutral-to-alkaline soil if it’s to survive our cool, damp winters and erratic summers.
Raised bed
If your garden is a wet one, then this shrubby plant will need a raised bed or container to protect its vulnerable root systems from succumbing to winter rot. If the soil is acidic, then it’s important to work some garden lime into the ground before planting (roughly a handful per square metre) while even in an average garden soil, it’s best to add generous amounts of coarse horticultural grit or gravel before planting to help improve drainage and aeration.
Lavender is fast-growing but naturally quite short-lived; it typically needs to be replaced after no more than a decade but can easily be propagated from cuttings taken in summer or early autumn. To extend longevity and keep plants neat, healthy and floriferous, regular pruning in April (lightly) and then again in late August or early September (a hard trim back to 1-2cm above the old wood) is essential. But never cut back into old wood as this can permanently harm or even kill established plants. This sort of regular pruning regime also results in the sort of plump but sculptural foliage growth that gives year-round evergreen interest and makes lavender plants look right at home in a topiary-style garden.
Springtime, as soil temperatures rise and the worst of the winter wet is behind us, is the best time to plant this versatile ornamental shrub. Of the several hundred different kinds available, varieties of English lavender (Lavandula angustifolia) and the hybrid species known as Lavandula x intermedia (a cross between Lavandula angustifolia and Lavandula latifolia) are best suited to the Irish garden.
The hardiest is English lavender, a large species that can tolerate temperatures as low as -15 degrees. It includes enduring classics such as L “Hidcote” (height and spread of 60cm x 75cm), a compact, very long-blooming variety with silver, aromatic foliage that produces its dark violet-blue flower spikes in flushes throughout the summer. Lavandula “Munstead”, slightly more compact in growth – it reaches an average height and width of 45cm x 60cm – is another classic, long-flowering variety of English lavender named after the famous English gardener Gertrude Jekyll’s garden, Munstead Wood in Surrey , with mid-violet-blue flowers that are paler than those of “Hidcote”.
White-flowered variety
For gardeners in search of something a little different, seek out the white-flowered variety of English lavender known as Lavandula “Arctic Snow”, Lavandula “Blue Ice” (pale-blue flowers) or the lilac-pink form, Lavandula “Rosea”.
For a much taller plant, try Lavandula x intermedia “Grosso”, a vigorous, strongly scented hardy variety with plentiful spikes of violet-blue flowers that reaches a height and spread of one metre. Commonly known as “lavandin”, other varieties of this hybrid species suitable for an Irish garden include L “Edelweiss” (white flower spikes, 60cm x 90cm); L “Vera” (very deeply scented, purple flowers, 1.1m x 1.1m) and the more compact L “Olympia” (dark-purple flowers, 60cm x 60cm).
While rarely seen for sale and just a little less hardy (it will tolerate temperatures down to minus 10 degrees) , the hybrid species known as Lavandula x chaytorae is also worth seeking out, as much for its beautiful silver-white, architectural foliage as for its very pretty, bee-friendly, dark-purple, perfumed flowers. Different varieties of French lavender (Lavandula stoechas) are also often seen for sale in Irish garden centres and are easily identified by their wider leaves and their rabbit’s-ear type flowers, which are larger but less plentiful than those of English lavender. Lovely as these are, bear in mind that this species is only borderline hardy in this country, so unless you can give the plants a hot, sunny, very sheltered spot with protection from low temperatures and cold winds, they sadly won’t survive the average Irish winter.
(Never use lavender for its medicinal properties without first seeking out expert advice.)
This Week in the Garden
April is a very busy time of the gardening year as regards sowing seed of many different kinds of vegetables. Examples that can be sown under cover over the coming weeks for planting outdoors as young transplants in late spring include cabbage, cauliflower, beetroot, lettuce, perpetual spinach, chard, scallion, kohl rabi, rocket, kale and turnips.
This is a great time of the year to pot on/pot up houseplants that have become root-bound and/or are in need of fresh potting compost, something they’ll typically require every one to two years. Signs that plants are in need of repotting include poor growth, their roots pushing through drainage holes in the base of the pot in search of nutrients or water, very top-heavy-growth (this suggests the pot is too small), and the compost or potting medium drying out very quickly between watering. When repotting any house plants, make sure to use fresh compost, and if you are potting it up into a bigger container, choose a new pot (ideally one with drainage holes) that’s just a little larger than the original. Any bigger and you run the risk of your house plant’s root system rotting in a sea of damp compost before it properly re-establishes itself. For best results, gently shake no more than a third of the old compost/ potting mix from the roots, place a shallow layer of fresh compost at the base of the pot and then position the plant in the pot to the correct planting depth before gently back-filling with more fresh compost. Finish off by placing the pot up to its knees in a basin of clean, tepid water and leaving it to bottom-soak for a couple of hours.
