Continue to plant deciduous
hedging plants, shrubs, trees and climbers. Stakes and rabbit guards
should be put in place at the time of planting trees, to prevent damage
to the rootball or bark.
Towards the end of the month, you can plant evergreen shrubs and
trees left unplanted since the autumn.
In warmer areas, evergreen trees and shrubs can be moved in late
March. It is better to wait until early April in colder areas. Make sure
the soil is not waterlogged or frozen solid, and bear in mind that they
will need careful attention to watering if they are to survive their
first summer after moving.
If you are hesitant to move large trees and shrubs so close to the
summer, then you can prepare mature specimens for moving next autumn.
Digging a narrow trench around the plant, cutting some of the roots in
the process, encourages the growth of finer, fibrous roots, rather than
the thick tap roots which are harder to remove successfully, and which
absorb water less efficiently.
Feed trees, shrubs and hedges with a balanced fertiliser (such as
Growmore or blood, fish and bone), sprinkling it over the root area
before hoeing into the soil surface. This will particularly benefit
young, weak, damaged or heavily pruned plants.
This is the best month for planting roses in heavy soils or in cold
areas. Avoid planting in areas where roses were previously grown,
otherwise new introductions may suffer from replant disease.
Prune established bush and standard roses as they start growing but
before any leaves unfurl.
Roses will benefit from feeding with a granular rose fertiliser as
they come into growth.
Many summer or late-summer flowering deciduous shrubs can be pruned
between January and March. Examples include
Buddleja davidii,
Caryopteris clandonensis,
Ceratostigma,
Hydrangea paniculata,
Leycesteria,
Lavatera,
Perovskia, hardy fuchsia, and
deciduous Ceanothus species.
Shrubs such as Buddleja davidii,
Salix alba var.
vitellina cultivars,
Eucalyptus gunnii and
Cornus sanguinea cultivars are
usually stooled (i.e. cut back very hard), because this keeps them at a
manageable size, as well as deepening the stem colour of those species
grown for their winter stem colour.
Delay pruning spring-flowering shrubs until after they have flowered,
otherwise this year's display will be lost.
Delay pruning spring-flowering shrubs until after they have flowered,
otherwise this year's display will be lost.
Do not prune slightly tender evergreen shrubs (such as
Choisya, best left until April),
but do tackle hardier examples (such as
Prunus laurocerasus, the cherry
laurel), if necessary.
Remove any reverted green shoots on hardy variegated evergreens, to
prevent reversion taking over.
Deciduous flowering Prunus
species (ornamental cherries, plums and almonds) are vulnerable to
silver leaf if pruned before mid-summer, and anyway should not require
routine pruning if planted with sufficient space for their eventual
size.
Check tree ties and stakes. Replace, tighten or slacken them where
necessary.
Firm back newly planted trees and shrubs if they have been lifted by
strong winds.
Check protective coverings on newly planted or borderline hardy
trees, shrubs and climbers, to ensure they remain secure until the risk
of frost has passed.
Remove weeds from around the bases of young trees.
Mulch and feed shrubs, trees, hedges and climbers after pruning, to
give them energy for the extra growth they will put on after cutting
back.
Maintain pruning on pollarded trees such as willow (Salix)
and lime (Tilia), cutting back
all growth to within two or three buds of the crown.
If your trees are too large for you to manage pruning alone, you may
need a tree surgeon. Otherwise take care not to damage the tree when
sawing off thicker branches.
Tie wall shrubs and climbers onto their supports to protect them from
wind damage.
Spur-prune all current stems on
Campsis by cutting back the laterals to within two or three buds of
the main branches forming the framework.
Cut back late summer and autumn flowering (group 3)
Clematis, if not done last month.
Cut to the lowest pair of strong buds above ground level, mulching and
feeding afterwards.
Prune winter-flowering jasmine once the flowers have faded. Remove
any dead or damaged shoots, tie in new shoots to the main framework, and
then shorten all the laterals coming off the main framework to 5cm
(2in), cutting to a bud. This will keep the plant neat, and improve
flowering next year. It is a good idea to feed and mulch after pruning,
as the plant will put on lots of growth in response to cutting back.
Summer-flowering jasmines may also be pruned (if necessary),
providing that they are reasonably hardy in their situation. With these
you should remove a couple of stems completely to ground level, and
avoid cutting back laterals, as this would damage the current year’s
flowering potential.
Overgrown climbers can be renovated this month. With deciduous ones,
you should now be able to tell which growth is dead and which alive, as
the live stems will show buds bursting into life. Suitable climbers
include Lonicera (honeysuckle),
Hedera (ivy) and rambling roses.
Trim winter-flowering heathers as the flowers fade. Shears are the
ideal tool. This will prevent the plants from becoming leggy and bare.
Sow tree seeds that have been kept in cold storage since collection
in the autumn.
Cut out the top rosette of leaves from leggy stems of
Mahonia x media cultivars to
encourage branching.
Check hardwood cuttings taken last year. They may need planting or
potting on.
Layering is a good way to propagate climbers and lax-stemmed shrubs.
Layers should root by next spring, as long as some attention to watering
is given during dry weather. Examples to try include
Philadelphus,
Forsythia,
Hydrangea and
Lonicera.
Pest & disease watch
Put rabbit guards around newly planted trees and shrubs to protect
the bark.
Avoid planting in areas where roses were previously growing otherwise
new introductions may suffer from replant diseases.
Inspect sick looking box and holly trees for signs of blight.
Bracket fungus on trees is more visible at this time of year. If the
tree is in poor health it is worth calling in a tree surgeon for a
professional opinion.
Phytophthora root rots can
cause die back on mature trees and shrubs. Wet winter weather and poorly
drained soils are likely to encourage this problem on susceptible woody
plants.
Check for damage or cankers on deciduous trees.
Be aware that pests emerge as the weather gets warmer. Caterpillars,
aphids and fly pests may all become problematic during mild spells.
Early infestations can often be managed by hand removal, making
insecticides unnecessary.