The English Garden – September 2019

86 THE ENGLISH GARDEN SEPTEMBER 2019

with a banana, which will hopefully turn them
red, and put old plants on the compost heap.
Untangle cucumbers from their supports, pick the
last peppers, and have a clear out of end-of-season
detritus: old plant labels, module trays that have split
or cracked, sun-bleached, half-finished packets of
seeds. Remove any shading that went up during the
sunnier months.
While the clear-up needn’t be too obsessive, it is
important to remove spent plants and old foliage,
to reduce the risk of botrytis – the fluy grey mould
that plants are more susceptible to in cool, wet
conditions. When the greenhouse is empty, you can

wash benching and glass with a

disinfectant like Citrox to further

reduce the risk. Although some

say this level of hygiene isn’t really

necessary, a side-benefit is that it

cleans the glass of dirt and green

algae, which lets in more precious

sunlight over these gloomier

months – maximising light is

essential for healthy plant growth

over winter. Definitely do it if you

experienced problems with pests

such as red spider mite during the

summer months.

If the prospect of a sponge, a

bucket of soapy water and hours

of elbow grease engenders feelings

of dread, Hartley Botanic can

supply and build a greenhouse

that has self-cleaning glass. And

some greenhouse suppliers oer a

cleaning service, such as Alitex’s

Clean and Care Service, which

involves a hot water jet wash,

followed by disinfectant and a

check on all the moving parts:

hinges, vents and lever arms. This

is also the time to have any broken

panes of glass replaced and repair

cracks or damaged seals.

Over-wintering

plants under glass

Most of us use the greenhouse to

keep frost-sensitive plants safe over

winter, so as the temperature starts

to drop, begin bringing plants

inside. It’s as well to thoroughly

check over pot plants before

putting them in the greenhouse,

removing any dead leaves, old

flower stalks and lurking snails and

slugs. Check that the plants are

firmly anchored in their compost

• no root damage courtesy of vine
  weevil grubs – and that they’re otherwise healthy.
  No point expending eort and potentially costly
  heating to keep plants that aren’t worth it.
  Some plants will need cutting back. Pelargoniums,
  for example, are usually cut back by about half
  and their leaves removed. Woodier plants such as
  fuchsias and lemon verbena can be left unpruned,
  their dead stems cut back in spring once you can see
  where new shoots are springing from.
  What happens next depends on whether or not the
  greenhouse is heated. To give tender plants the best
  chance of surviving winter, the temperature really
  needs to be at least 7°C and ideally 10°C. In the UK,

Above Dig up and pot

a clump of lily-of-the-

valley to force it into

earlier flower using

the warmth of the

greenhouse.

AUTUMN GREENHOUSE