Amateur Gardening – 20 July 2019

20 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

Can black spot travel from roses to

other plants? Our honeysuckle also

seems to be suffering.

Mark Potter, Blackburn, Lancs

A

I am sorry that your roses have

succumbed to black spot disease.

The best way to control it is to spray

with RoseClear Ultra Gun, which also

tackles powdery mildew, rust and

aphids effectively, or FungusClear

Ultra Gun that protects plants for

more than four months.

Alternatively, use Bayer Garden

Fungus Fighter, which guards roses from

attack for up to three weeks.

Additionally, feed bushes with

1oz (28g) per m^2 of sulphate of potash.

Sprinkle it over the root area monthly,

from April to September, and water it in.

Potash strengthens growth and builds

resistance to infection.

Other funguses can cause problems

for honeysuckles, but not black spot.

Treat plants with FungusClear Ultra Gun

or Fungus Fighter Plus and feed them.

Does black spot spread from roses?

Q

I planted what was described as

a ‘miniature’ camellia about 14

years ago. It is about 4ft (1.2m) high and

about 5ft (1½m) wide! How and when

should I prune it?

Graeme Yarwood, Haddington,

East Lothian

A

If you would like to reduce your

camellia by 12in (30cm) or so,

tackle it now. It doesn’t matter where

you start – top or bottom – the important

thing is to maintain a rounded symmetry.

Use sharp secateurs and, ideally, cut

to just above a leaf. Strong new shoots

should soon appear.

In future, if you wish to prune your

camellia, do it when blooms fade in late

spring. It won’t mind being pruned now,

but May or June are better months as

cuts heal more quickly then.

When should I cut back our camellia?

Black spot is specifi c to roses but other plants

have their own fungal problems

Q

What can I use to kill off a tree

stump and roots?

Derek Beard,

Maidstone, Kent

A

If the roots

are too

large to dig out,

drill 1∕2in (13mm)

holes in the stump

and fill them with

SBK Brushwood Killer or

Roundup Tree Stump and Root Killer.

When the liquid has seeped

away, top it up. Repeat several times.

Quick questions

& answers

Q

Please can you tell

me what this

plant is?

Norman Bailey,

Warrington,

Cheshire

A

This tall,

stately plant

is Nicotiana

sylvestris (flowering

tobacco). The elegant white flowers

have a lovely sweet fragrance

released at dusk.

Nicotiana sylvestris is a biennial

or short-lived perennial, but it is best

grown as a half-hardy annual from

seed each year in our cold climate.

Please can you tell

me what this

stately plant

(flowering

Q

I thought this was lavender –

but what is it?

Caroline Smith, via email

A

I feel sure that your plant is

black rampion (Phyteuma

nigrum). A native of

Belgium, France and

Germany, it

frequents

mountain

meadows and

open woods to

a height of

4,000ft (1,200m).

It is pretty and, if

you grew it on in a

lightly shaded patch, it should

proliferate and become an

appealing feature.

The best time to prune camellias is

in late spring after fl owering

stump and roots?

Maidstone, Kent

holes in the stump

SBK Brushwood Killer or

). A native of

Belgium, France and

4,000ft (1,200m).

It is pretty and, if

you grew it on in a