LUPINS LEAD THE WAY
These favourite perennials won’t let you down, but they need support
FOR more than a century, lupins have been among Britain’s most-loved perennials. Their colourful flower spikes and spicy fragrance make them a long-standing border favourite. Lupins are easy to grow. And although they flower in June, that distinctive pinnate foliage stays decorative all summer. There are also close relatives of the lupin which flower at other times.
If you want your lupins to be tall and distinctive, buy named varieties from specialists such as westcountrylupins.co.uk.
Alternatively, buy seeds of selected strains such as Russell Mix from suttons.co.uk or the new Tutti Frutti from thompsonmorgan.com. Lupins are easy from seed and flower a year after sowing. They’re long-lasting, but should be split and re-planted every third or fourth year.
If you already grow lupins, the heatwave probably shortened their flowering spell. Help them recover by cutting dead flower stems off at ground level and watering the plants. You may get more flowers later.
Named cultivars have the richest colours. Many are twotone with contrasting petals. Others come in single tints from white, through blues or pinks to midnight violet or brick red. Varieties such as these are suitable for big pots or half-tubs as well as borders.
For wilder planting schemes, lupins will naturalise by selfseeding. They need a sunny site with free-draining soil. EASY CARE OCTOBER is the best month for dividing older plants, but you can also do it in March. They have deep roots, so you may have to slice them apart with a spade. You can also take cuttings in spring when the basal shoots are less than 10cm. Insert several into a pot containing a 50/50 mix of potting compost and Perlite or grit. They’ll root in a cold frame or greenhouse.
Lupins are largely trouble-free, but have one serious pest: lupin aphid. Young flower stems become encrusted with colonies of the greyish bugs. You can rub them off with your fingers, but young lupin tissue is delicate and easily damaged. Organically approved contact insecticides such as natural pyrethrum give some control, but they must be sprayed directly onto the pests.
Chemical or systemic insecticides such as acetamiprid may be effective, too. But if applied during budding or flowering, could harm valuable pollinating insects, such as bees.
CLOSE RELATIVES
GARDEN lupins were developed from Lupinus polyphyllus — an American wildflower introduced to Britain in 1826. In June, they’re superb, but offer little at other times. Luckily, however, there are lupin relatives which extend that season. The Carolina Lupin, Thermopsis villosa and its dark-leaved relative, T. rhombifolia have yellow spikes, but the roots may need to be controlled as they can spread.
The most aristocratic lupin relative is Baptisia australis. Also from America, this tallgrowing perennial has beautiful grey-green foliage. But in late June, there’s a big bonus of spikes in deep indigo blue.
There’s even a lupin tree, though it’s really a rangy shrub.
Lupinus arboreus has short spikes of primrose flowers.
THE warm weather has been tough on our gardens. Most plants are still soft and sappy in June. That makes them vulnerable to winds and heat — both of which we have had this month. Temperatures may now have dropped, but the effects of sunny spells will last for a while. So, here are ways to keep your garden looking lovely all summer.
WATER WISELY
PLANTS need a lot more water in hot weather. Give container plants, the greenhouse and anything recently planted as much water as needed.
But irrigate established plants in beds or borders only if necessary. Try to water in the early morning or evening.
COOL YOUR GLASS
GREENHOUSE crops — tomatoes and cucumbers especially — react badly to overheating. Keep all vents and doors fully open in heat.
Shade the glass with paint-on material, such as Coolglass, or install shade netting.
Damp down your greenhouse with water frequently. But never spray cold water directly on to hot plants — they will scald.
CONTAINER CARE
CONTAINER plants are at greatest risk from extreme heat. Never allow the potting compost to dry out.
Pay special attention to pots exposed to wind or day-long sun and water those more frequently. It can help to arrange containers in close groups, so that some can shade their neighbours.
LEAVE THE LAWN
DON’T worry about your lawn. It may look stressed or go brown in drought. But the grass will perk up as soon as there’s damp weather. Save water for keeping other plants alive.
CHEER UP YOUR FRUIT
RASPBERRIES are shallowrooted and vulnerable to excess heat and drought. Water yours well and mulch their roots to conserve moisture.
It’s wise to mulch gooseberries and currants, too. Tree fruit — apples, pears, plums — should be fine, unless there’s a prolonged dry period.
CUT AND COME AGAIN
CUT back repeat-flowering plants now to encourage new growth. Penstemons, smallflowered violas, some campanulas and salvias will produce shoots if old stems are cut back.
Cut away seeding stems of antirrhinums, red valerian and foxgloves to promote shoots.
BRING OUT YOUR DEAD
IF HEAT has killed any of your plants, don’t despair. The gaps they leave provide new planting opportunities.
Replace losses with droughtproof alternatives, such as tall sedums, silvery artemisias or pearly everlasting (Anaphalis). Or buy potted tender varieties to make temporary gap-fillers.
RE-BOOT ROSES
REPEAT-FLOWERING roses suffered a premature end to their first flush. Prune away spent flower clusters.
Water if necessary. And consider spraying with a dilute foliar feed of seaweed extract. July will bring another flush.
REPAIR EARLY SHRUBS
HIGH temperatures shortened the flowering time of deutzias, mock oranges and other early summer shrubs. If you remove old stems that have flowered, strong new ones will develop for next year. Cut each old stem low down to encourage new shoots.
KEEP CLEMATIS COOL
BRITAIN’S most popular climber hates hot roots. To keep your clematis happy, make sure the roots are cool and shaded.
Thoroughly water clematis plants, then mulch the ground at the base of each plant.
CARE FOR WILDLIFE
KEEP your pond or bird bath topped up, or have water at ground level for small animals.
Avoid cutting back too much long grass or undergrowth — it’s a shady refuge for wildlife.