Lawns will be growing fast now, and can be cut at their seasonal shortest.
Try to avoid mowing when the grass is wet, to avoid smears.
Is your lawn three-dimensional with buttercups and dandelions? The soil is
warm and moist now, and the weeds are growing hard too, so it is the perfect
time to apply selective weedkillers. Apply them on a still day, and be
careful to avoid drift onto ornamental plants.
Minor patches of weeds can be cleared with a hand fork, and the odd
tap-rooted rosette-forming weed like dandelion can be killed by dribbling a
few spots of glyphosate into the centre of the rosette. Make sure you put
none on the lawn.
Grass containing crocuses, colchicums and snowdrops can be mown short now.
Pruning and Training
Keep tucking in the soft stems of clematis into their supports, so that they
cover the intended space and do not shade out evergreens.
Put in supports for heavy-headed paeonies at the beginning of the month, to
stop them flopping later.
Sow sunflowers in pots or in the ground.
Plant out cannas and dahlia tubers 3-4in under the surface, and mark them
with a cane set behind them, so you know where you can safely hoe and later
drive in a stake.
Grasses and the related bamboos prefer to be moved and divided now, while
they are coming into active growth. If you can slice through the clump and
take away a piece leaving the parent plant unmoved, so much the better.
Water the offsets well until re-established. Shorten the foliage or canes
if you need to reduce wind rock.
Lift and divide clumps of bluebells in dappled shade after flowering, while
you can still see the foliage.
Transplant ferns this month, just as the fronds start to expand.
Plant out aquatics into ponds.
This is real slug time. Deal with them by your favourite means. Beer
traps, fruit skins, slug pellets, etc.
Plant hanging baskets and patio pots. They can go outside at the end of
this month (or early next in colder areas) once the risk of frost is past.
Put them out on a still dull day first, to harden them off. Where vine weevils are a problem, it may pay to treat the pots with Bio Provado, at
least on highly susceptible plants such as busy lizzies.
Watch out for the little caterpillars of the gooseberry sawfly which can defoliate a bush in no time, and spray at once. Fortunately they succumb
readily to the milder insecticides.
Put straw or leylandii clippings amongst strawberry plants, to keep the soil
from splashing onto the setting fruits.
This is the month for sowing outdoors. Get busy with beans, beetroot,
carrots, ruby chard, leeks, parsnips, spinach, and salads like lettuce,
endive, parsley and rocket.
In pots, sow tomatoes, courgettes, pumpkins and sweet corn.