Amateur Gardening – 10 July 2019

6 JULY 2019AMATEUR GARDENING 37

Write to us:Ask John, Amateur Gardening magazine,

Pinehurst 2, Pinehurst Road, Farnborough Business Park,

Farnborough, Hants, GU14 7BF.

Email us:[email protected]

Q

How often do tomatoes growing

in a greenhouse need watering?

Anna Coulter, Aylesbury, Bucks

A

You should water as required,

especially in dry weather. Given

that your plants are in a greenhouse, this

can count as always being dry weather,

as they are totally dependent on

supplementary watering.

Test the compost to see if it feels dry.

If it does, then water, giving enough to

soak right through the full depth of the

container – a good drink less often is

better than a little drink more often.

If the compost feels damp (properly

damp, not borderline) and the plants

aren’t wilting, then it will probably be

OK to leave it for a day. If you are in any

doubt, then water, as allowing plants to

wilt, even briefly, can check their growth

as it takes time to recover.

As you suspect, both underwatering

and overwatering can lead to other

problems in tomato plants, as can

irregular watering. Underwatering can

lead to blossom end rot; overwatering

results in tasteless fruit or attack by

fungal diseases; and irregular watering

can result in splitting.

How often do I water greenhouse toms?

Q

Please can you identify this plant?

Mr E Jephcote, Ilkeston,

Derbyshire

A

This is the Japanese angelica tree

(Aralia elata) and is native to Japan,

Korea and far east Russia, so is quite

hardy in this country.

It is usually seen as a large suckering

shrub, but it can also be grown as a

smaller specimen tree. This doesn’t

produce many branches when grown as

a tree, but it makes an interesting shape

when in leaf and should colour up well in

autumn. Trees do flower in this country,

producing their large panicles of white

flowers in autumn that can be followed

by berries.

Enigmatic angelica

Irregular watering can cause splitting and blossom end rot in tomatoes (inset)

Q

Why haven’t my blackcurrants

fruited?

Terry Burnett,

Stirling,

Scotland

A

The

usual

reason for

blackcurrants

failing to crop is

that the flowers have been

frosted or weren’t visited by bees

or other pollinators.

We had a topsy-turvy start to

the year, when low temperatures

and light levels weren’t conducive to

good growth. Hopefully, next season

will be better!

Quick questions

& answers

Q

What are

these

little yellow

balls in a

garden

centre

plant pot?

Duncan

Grant, Builth

Wells, Powys

A

I suspect they are slow-release

fertiliser capsules. The nutrient

substance inside them permeates

the soil when it is watered. They

look a little like slug or snail eggs,

but they are much softer and never

become hard or crystalline.

What are

Grant, Builth

Wells, Powys

Q

Please can you put a name

to this plant?

Elaine Page, Necton, Norfolk

A

It is a species of cudweed,

probably Filago vulgaris.

This is hard to

hand-weed,

as the roots

will grip

the soil, so

treat with a

glyphosate

weedkiller

to kill the

whole plant.

The Japanese angelica tree is hardy

enough to grow in the UK

fruited?

Terry Burnett,

blackcurrants

failing to crop is

that the flowers have been

This is hard to

hand-weed,

as the roots

whole plant.

Alamy

Alamy