April in the garden

Spring is finally in evidence as daffodils and flowering trees start to bloom. Expect the inevitable April showers this month but with sunny days too, when you can turn your attention to the lawn.

It's an exciting month, with indoor-sown seeds well into growth, and it's also time to start sowing outdoors. Just watch out for frosts...

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Flowers

Sow hardy annuals, such as love-in-a-mist and pot marigolds, as well as native wildflowers, into gaps in borders
Enjoy instant colour by planting primulas and polyanthus in pots and at the front of borders
Protect the new shoots of hostas, delphiniums, lupins and other vulnerable plants from slugs and snails
Continue deadheading spring bulbs and bedding, so they don't waste energy setting seed
Plant pineapple lily (eucomis) bulbs in pots for exotic-looking summer flowers
Sow sweet peas at the base of supports, and transplant those sown in autumn into their final positions
Spray the new leaves of disease-prone roses with fungicide to control mildew, rust and blackspot
Take basal cuttings from clumps of perennials, such as delphiniums, campanulas and lupins
Prune hydrangeas, cutting back the old stems to a healthy shoot lower down
Reinvigorate mature clumps of hardy perennials, such as hostas, asters and daylilies, by dividing and replanting
Sow sunflowers in a sunny, open site, then water regularly and protect seedlings from slugs and snails
Check for aphids on roses and rub them off before they develop into major infestations
Add aquatic plants, such as waterlilies and irises, to garden ponds
Scatter general-purpose fertiliser over flowerbeds and around roses, shrubs and hedges

 

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Fruit and veg

Plant second-early and maincrop potatoes
Place cardboard collars around the stems of brassicas to deter cabbage root fly from laying their eggs
Pinch out the tips of broad beans if they're covered in aphids, or spray shoots with soap-based solution
Sow outdoor varieties of tomatoes, chillies and courgettes in pots, so they're ready to plant out in late May or June
Divide clumps of hardy herbs, such as lemon balm and chives, then replant in pots, borders or a dedicated herb bed
Sow small batches of rocket and other easy salad leaves
Continue planting bare-root asparagus crowns and Jerusalem artichoke tubers
Sow flowering companions in the veg plot, such as pot marigolds and borage
Continue planting batches of garlic, shallots and onions every few weeks to extend the cropping period
Sow herbs such as parsley, coriander, dill and chamomile in a sunny bed or container
Protect emerging seedlings from slugs and snails
Sow fast-growing crops, such as radishes, to make the most of any temporary gaps
Sow radishes in gaps for an extra crop

 

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Greenhouse

Prick out seedlings growing in pots and trays as soon as they produce their first true leaves
Sow sweet peas in deep pots and keep them frost-free in a greenhouse or on a sunny windowsill
Start feeding houseplants once a week with liquid fertiliser, continuing through to autumn
Sow quick-growing microgreens, such as kale and mustard, for nutrient-rich pickings in just a few weeks
Transplant greenhouse tomatoes into growing bags or large containers and tie in the stems to supports
Plant up hanging baskets and pots with summer bedding, but keep indoors until after the last frost
Sow herbs in pots or trays, including basil, chives, parsley, fennel and coriander
Thin out heavy fruit sets on peaches and nectarines, leaving fruits about 10cm apart
Sow runner beans, French beans, cucumbers, courgettes, pumpkins and sweetcorn in pots
Pinch out the shoot tips of fuchsias to develop bushier plants
Attach guttering to the greenhouse and install a water butt, so you can make good use of April showers
Clean greenhouse glazing to let in as much light as possible
Maintain good plant hygiene, picking off faded blooms and dead leaves before fungal diseases can take hold
Sow sweet peas in deep pots and protect from frost

 

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Garden maintenance

Put a bag of barley straw in ponds to discourage algae and keep the water clear all summer
Lay turf or sow grass seed to create a new lawn or repair damaged patches
Cut back tatty old fern fronds to make way for new ones that are starting to unfurl
Keep cloches or large sheets of fleece handy to protect young plants if late frost is forecast
Cut away unwanted suckers growing around the base of trees and shrubs
Hoe between rows of veg seedlings regularly, as weeds grow rapidly at this time of year
Remove moss and weeds in turf, and boost growth with a nitrogen-rich lawn feed
Check that guttering on sheds and greenhouses is clear of debris, so that April showers will fill up water butts
Add new aquatic plants to ponds and divide established plants that have outgrown their baskets
Put pumps and fountains back into ponds, thoroughly cleaning the filters first 
Treat problem weeds, such as nettles and brambles
Look out for clusters of aphids on shoot tips and young leaves, and wipe off before they multiply 
Keep putting out food for birds, as they're busy raising their broods

 

Source: BBC Gardeners' World