Amateur Gardening – 13 July 2019

13 JULY 2019AMATEUR GARDENING 39

Anne Swithinbank’s masterclass on: cherry problems

Q

We have a cherry on a dwarfing

rootstock. Some years, it doesn’t

set fruit – but this year, there was a lot

of blossom and many green cherries.

They all disappeared without ripening,

and leaves became curled and distorted.

What can I do to help it?

Emily Proctor, Harrogate, North Yorks

A

There was a good set

on cherries this spring,

even on the wild ones at

the bottom of our garden.

Cherries flower early and

in some years, pollination

is compromised by late

frosts or wet, blustery

weather. Make sure you

plant them in sheltered

locations and avoid frost

pockets. On poorer soils,

or where nutrients are

washed away by winter rain,

spring feeding and mulching are

important. A dry spring (especially on

sandy soils) can cause fruit to drop early.

Our ‘Sunburst’ cherry tree is planted

in the kitchen garden, right under my

nose, so I noticed as soon as pigeons

began tugging at immature cherries.

The fruits were like green bullets, but

the birds must have been short of food

• or even water. I was straight out with
  horticultural fleece, a step ladder and
  clothes pegs to wrap a portion of the
  small tree and put water out for the birds.
  Cherries are often badly affected by
  blackfly, as their sap-sucking causes
  leaf curling at shoot tips. I prefer
  to leave this problem to
  naturally occurring parasites
  and predators rather
  than winter washes and
  sprays, which can deter
  or harm the ‘good bugs’.
  Tellingly, the covered
  portion of my cherry
  suffered more infestation
  than the uncovered portion,
  since the latter was more
  accessible to natural controls.
  A large fruit cage that supports netting
  rather than mesh or fleece is ideal. You
  can nip off and destroy heavily colonised
  leaves, but this also reduces natural
  predator numbers.

What’s ailing my cherry?

There was a good set

on cherries this spring,

washed away by winter rain,

blackfly, as their sap-sucking causes

leaf curling at shoot tips. I prefer

to leave this problem to

naturally occurring parasites

and predators rather

than

sprays, which can deter

or harm the ‘good bugs’.

Tellingly, the covered

portion of my cherry

suffered more infestation

than the uncovered portion,

since the latter was more

accessible to natural controls.

Body image: Alamy. All other photography John Swithinbank / TI Media, unless credited

Cover young and immature fruits

as soon as birds show an interest.

Ensure a

healthy crop

Blackfly colonies will soon be

ravaged by ladybirds, the larvae

of lacewings and hoverflies,

predatory wasps, parasitic mites

and flower bugs.

Blackfly is a common problem,

especially as their life cycle means

that eggs are on the trees ready to

hatch in spring.

Despite infested, distorted shoot

tips, the health and fruit bearing of

the tree is not normally affected.

Anne’s

top tips

A cunning life cycleÉ

CHERRY blackfly is a specific aphid (Myzus cerasi)

overwintering on the trees as eggs. They hatch

into wingless adults in spring, feeding inside the

curled leaves in vast numbers. Winged adults

will appear in June, starting a migration to their

secondary host, bedstraws. Cherries are aphid-free

from July, but the fly returns in August to lay eggs.

It’s a good idea to put

water out if you see birds

pulling at immature fruits

Self-fertile ‘Stella’ cherry

crops in late July

Taking action to protect cherries

from hungry (and thirsty) birds

should deliver a good harvest

of fruits. I always let the birds

have a few at the end

Cherry leaves infested

with Myzus cerasi Inset: Alamy

If you have only one

cherry tree and there

are none nearby, it will

need to be a self-fertile

variety like ‘Sunburst’

or ‘Stella’.

Inset: Alamy