Garden News September 5

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September 5, 2015

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EXCLUSIVE!

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Daring dahlias with weird & wonderful blooms

Sneak preview of Carol Klein's new book!

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Create an easy

mini-meadow!

RELIABLE ROSES Varieties that coped with 2015's strange summer!

How to get

GERANIUMS ready for winter

MAKE THE MOST OF

PLUMS! Cakes, jam & harvesting tips

Fill your garden with

flowers! als Sow the best, brightest hardy annu Plan vibrant spring bulb displays r Plant climbers for colourful cove

E G SCULPTUanRts! Grow a LIVIN g, architectural pl Amazin

AboutNOW This Asian pest has established itself in the UK

Alamy

Pandora’s new box

What to look for ● Sheets of pale-yellow eggs

Voracious pest devastates hedge plantings

are laid beneath leaves

● Caterpillars are up to 4cm (1¼in) long.

Words Ian Hodgson

T

he latest foreign invader is on the march and could soon be in a box hedge near you. Box-tree caterpillar, Cydalima perspectalis, is a voracious muncher of box (Buxus sempervirens), an infestation soon stripping the evergreen bushes back to bare twigs.

The latest pest from Asia was first reported in the UK in 2008, but by 2014 the

inch-long moth had already established itself in parts of London. This year the RHS have already received 150 reports of the caterpillar, up to three to four per day. This compares with only 20 last year, and just three in 2011.

Infestations have appeared outside the M25 corridor and in Essex. The National Trust (NT), whose gardens often use box extensively, has currently reported only one outbreak, at

Carlyle’s House in Chelsea.

“The key thing is that it is established – it has survived the winter and is breeding,” said Dr Hayley Jones, an entomologist with the RHS. After establishing in Europe in 2007, it entered the UK by either flying across the channel or stowing among imported plants. ● The NT and the RHS plan to hold a joint training event for professional gardeners on box pests and diseases in November.

Growing family are champs

(seven) bagged the top prize of £1,000 of gardening vouchers. Judges praised their expert workmanship and ingenuity, as well as their ability to grow a wide array of crops.

4 Garden News / September 5 2015

Sean Cameron

A

family from Manchester has scooped the title of Britain’s Best Allotment.

Geoff and Rachael Hill and children Jordan (12), Dominic (nine) and Drew

in white webbing spun along foliage ● Caterpillars feed beneath a canopy of white webbing ● Moths have white or brown wings, 4cm (1¼in) across

Control ● Organic: remove by hand, or spray pathogenic nematode Steinernema ● Chemical: spray products containing pyrethrum or deltamethrin

Plot size ‘poppycock’

C

The Hill family’s allotment (left) and with judge Sean James Cameron (top)

● Pupae are concealed

The competition was run

by Hippo Bags, in association with the National Allotment Society. ● Visit www.hippobag.co.uk/ blog/britains-best-allotmentwinner

harlie Dimmock’s recent comments regarding allotments have landed her in hot water. The Garden Force presenter suggested the standard plot size of 250sq m (2,690sq ft) could be quartered, to reduce waiting lists.

Tony Heeson, chairman of the National Allotment Society, views her suggestion as ‘plain poppycock’, potentially putting ‘seriously interested gardeners off’, by not providing enough Dimmock – size space for useful quantities of controversy produce. “While celebrities follow their celebrity lifestyle, ordinary people with ordinary aspirations get on with what we do best, including allotment gardening,” said Tony.

Plant

OF THE WEEK

Six daring varieties to try

Try these unusual varieties with extravagant blooms and fab colours

T

he dahlia can be teased with breeding into the most extraordinary forms.

There are the decorative and cactus dahlias, with spiky double flowers, the near perfect spheres of the ball and pompon dahlias, and the collerettes with their elaborate ruffs of petals.

Then there are the dahlias that simply can’t be classified, like those where the petals have rolled in on themselves, creating tubes. ‘Juul’s Allstarr’ is one, with yellow and pink petals, or pure red ‘Marie Schnugg’.

Of the dahlias with unusual colour variations, ‘Twyning’s Smartie’ is striking, with pink and white petals on the same flower. ‘Giraffe’ and ‘Pink Giraffe’ have subtle but unusual stripes.

Fa ct

Photos: National Dahlia Collection

Dahlias!

‘Tioga Spice’

‘Honka Surprise’

This explosion of a double dahlia has tapered pinkyellow petals that form a ball shape. Height 90cm (3ft).

A compact plant up to 60cm (2ft) tall, with curling yellow and salmonpink flowers.

‘Giraffe’

‘Tahoma Moonshot’

A unique double dahlia, with a tiger-stripe effect.

‘Pink Giraffe’ is a pink version. Height 90cm (3ft).

A tall, velvety, star-shaped dahlia, in a deeper colour than ‘Honka Surprise’.

Height 100cm (39in).

‘Blue Bayou’

‘Mayan Pearl’

Lavender outer petals with a rosette of tight deepburgundy central petals.

Height 100cm (39in).

A prolific flowerer, the crimped petals are tough, weathering any conditions.

Height 90cm (3ft).

Keep them happy Dahlias grow in most soils and are happy in containers, too.

Make sure the soil has plenty of organic matter. They prefer a sunny spot but need to be kept moist at the roots throughout the growing season. Feed monthly, and weekly when flower buds appear.

Deadhead regularly to ensure flowering continues into autumn. Dahlias originated in the high mountain regions of Mexico, so bloom happily in cool conditions. After the first frosts have wilted the foliage, lift the tubers and invert somewhere dry for a couple of weeks. Then store in just-damp compost somewhere cool but frost-free for winter.

Pompon dahlia varieties are the toughest: they’re extremely resistant to cold and rainy weather.

Subscribe now for £1 an issue! Go to www.greatmagazines.co.uk/gn

● All available to order from The National Dahlia Collection, tel: 07879 337714; www.national-dahlia-collection.co.uk

September 5 2015 / Garden News 5

MARTIN FISH

The undercover

GARDENER Former head gardener, TV and radio broadcaster and RHS judge

Tomato challenge

Jo b s to do now

I’ll be doing all I can to get mine to ripen!

Trim back grapevine foliage To help my grapes ripen, I’m trimming back foliage and new shoots that are shading the fruits. This allows the sun to reach the grapes that are now changing colour.

Photos: Martin Fish

We’ve got lots of fruit, but they’re all still green!

G

etting tomatoes to ripen can be a problem and this year, with the season a couple of weeks behind, it will be even more of a challenge. The plants have grown well in my greenhouse and polytunnel and set a good crop of fruit, but ripening started two to three weeks later than it did last year.

Normally by this time we have a glut or fully ripe fruits, but it hasn’t happened.

The reason is purely down to the weather.

Tomatoes like plenty of warmth to ripen and although we’ve had some warm days undercover, at night the temperatures have plummeted.

I popped a thermometer outside back in mid-August and it got down to 3C (37F).

Undercover at night it has been down to 6C (43F), which is chilly for the time of the year.

I’m not a fan of green tomato chutney, so I will be doing all I can to encourage my tomatoes to ripen over the next month or so!

The first thing to do is to remove the growing point, if you haven’t already. This

stops the plant trying to produce more flower trusses and wasting energy. Secondly, good air flow is essential to help the ripening process and to prevent moulds developing in cool, humid conditions, so I’m removing some of the lower foliage.

Normally I wait for the leaves to turn yellow, because while they’re green they are producing food for the plant. Feeding with a high potash fertiliser continues on a weekly basis, but I do cut back on the watering a little to maintain a slightly drier atmosphere around the fruits.

And, of course, I try to keep the air temperature as warm as possible at night by closing the doors and windows in the afternoon to build up the heat for overnight. With a little extra care and attention, hopefully the fruits will start ripening soon!

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Tel: 01531 633659 www.haygrove.co.uk

Subscribe now for £1 an issue! Go to www.greatmagazines.co.uk/gn

Give clivias a high potash feed for winter To induce winter hardiness and encourage flowers next spring, I’m feeding my clivia plants with a high potash fertiliser.

Remove dead and mouldy foliage from plants Cooler nights and moisture in the air can cause mould, so pick over plants and remove dead, yellow or mouldy foliage.

September 5 2015 / Garden News 29

What to do this week

ON YOUR FRUIT & VEG PLOT

I

f you haven’t dug them all up already, it’s time to harvest the last of your maincrop potatoes. Although they’ll sit underground for a while without coming to any harm, now the weather has turned cooler and it’s getting wetter, they need to be dug up and stored. Left in the soil they’re at risk of rotting, or suffering slug damage.

It’s important to dig up all the tubers and not leave any behind.

Missed tubers spring up the following year – they’re known as ‘volunteers’ – and have an irritating tendency to emerge directly where you’ve sown a lovely neat row of something else.

Not only that, they spoil your orderly crop rotation plans and can carry disease from one year to the next, so sift through the soil with your fork and make sure that every single potato goes into your bucket or trug.

While you’re digging, you’re bound to come across the withered seed potato that you originally planted, and this needs removing too, as well as any remaining haulms (potato stems and leaves) that are still present.

Dispose of these carefully. A couple of years ago, potato farmers accused home gardeners of proliferating blight by not getting rid of spent potato haulms properly. While gardeners and allotment owners fought back, it is true that the disease’s spores can overwinter both in the soil and on foliage that hasn’t been cleared away. When you’ve dug your crop, either bury the plant waste at least 45cm (18in) deep, put it in your green waste bin for council composting that reaches higher temperatures than your domestic heap, or burn it.

Potatoes need to be dug up and stored now

30 Garden News / September 5 2015

Harvest your last potatoes Dig them up now to stop rot setting in, says Clare

Remove all roots and stems to prevent disease spreading