Tie in climbing and rambling
roses as near to horizontal as possible. This will restrict sap flow
causing more side-shoots to grow along the length of stem. Therefore
more flowers will be produced.
Hyrbid tea roses can be disbudded, removing all smaller buds from the
cluster that forms at the shoot tip, leaving the largest central (or
‘king’) bud to develop into a large, show-stopping bloom.
Prune out any remaining frost damage from affected evergreen shrubs.
Cut back tender shrubs such as
Penstemon, Caryopteris and
hardy fuchsias after danger of frosts has past.
Prune flowering shrubs such as
Deutzia, Kolkwitizia,
Weigela and
Philadelphus after they have
finished flowering. If this job is left too late, the new growth put on
after pruning may not have sufficient ripening time to flower well next
year.
Evergreens such as Viburnum tinus
can also still be trimmed this month.
Clip evergreen hedges such as privet (Ligustrum),
box (Buxus) and
Lonicera nitida if needed. If
they are not too woody, shredded clippings can be added to the compost
heap.
Prune deciduous magnolias once
the plant is in full leaf. If this is done in winter, when the tree is
dormant, dieback can occur, and pruning in late winter or spring can
result in bleeding. Midsummer is therefore recommended.
Thin out new shoots on trees and shrubs pruned in winter if necessary
to prevent overcrowding.
Rhododendrons can be lightly pruned after flowering. More severe
pruning should wait until the following early spring.
Thin out new shoots on trees and shrubs that were pruned in winter to
stimulate growth. Remove crossing stems and prevent overcrowding of new
growth.
Prune overcrowded, dead or diseased stems of
Clematis montana once it has
finished flowering. Untangling the stems can be fiddly, but once you can
see where you are cutting, you need not worry about pruning this plant -
it will take even hard cutting back very well.
Twining climbers (such as honeysuckle and
Clematis) need regular tying in
and twining around their supports.
Young mimosa trees (Acacia dealbata)
can be cut back once all risk of frost has passed. Mature trees respond
less well to hard pruning.
Prune wall-trained pyracanthas, removing any shoots coming out from
the wall, and shortening other new growth to about 8cm (3in). This
encourages spur formation, and increased flowering relative to green
growth.
Remove any reverted green shoots on hardy variegated evergreens, to
prevent reversion taking over.
Prune wall-trained pyracanthas, removing any shoots coming out from
the wall, and shortening other new growth to about 8cm (3in). This
encourages spur formation, and increased flowering relative to leafy
growth.
Ensure newly planted trees and shrubs do not dry out. Water with
rain, grey or recycled water wherever possible.
Loosen any tree ties that are digging into the bark, or could do so
soon as the trunk girth expands.
Take softwood cuttings of deciduous shrubs, including
Caryopteris,
Forsythia,
Kolkwitzia, lavender and rosemary
if not done last month.
Take softwood cuttings of many deciduous shrubs, including
Fuchsia,
Hydrangea macrophylla,
Philadelphus and
Spiraea.
Layering is a good way to propagate climbers and lax-stemmed shrubs.
Layers should root by next spring, especially if attention to watering
is given during dry weather. Examples to try include
Philadelphus,
Wisteria,
Akebia and
Lonicera.
Sprinkle fertiliser around perennials, shrubs and roses.
Water around the crown of tree ferns, especially newly planted ones.
Dig out tree and shrub suckers. If sucker removal is difficult, sever
the root to isolate the sucker from the parent tree and then carefully
treat the sucker with ammonium sulphamate (as found in products such as
Amcide or Root Out).
In wet areas, you can still plant containerised trees and shrubs. But
if summer rainfall is scarce, then planting is best avoided. You would
be wiser to wait until autumn, when the weather will work with you
rather than against you to ensure the successful establishment of your
new trees and shrubs.
Pest & disease watch
Check roses for signs of blackspot, aphids and leaf-rolling sawfly
damage.
Viburnum beetle grubs start nibbling holes in the leaves this month,
giving plants a tattered appearance. Inspect
V. tinusand
V. opulus regularly and spray or
pick of the grubs by hand.
Inspect sick looking box and holly trees for signs of blight.
Phytophthora root rots can
cause die back on mature trees and shrubs. Wet winter weather followed
by a hot spring and summer can encourage this problem on susceptible
woody plants.
Check for damage or cankers on deciduous trees.
Caterpillars, aphids and other fly pests can all be problematic at
this time of year. Early infestations can be managed by hand removal,
but approved insecticides are necessary for more serious attacks