National GardeningWeek (UK) takes place in April. During this time private gardens normally closed to the public are opened to visitors. For more information go to: http://www.nationalgardeningweek.org.uk
- Watch out for late frosts and protect tender plants with fleece.
- Tidy borders, pull up weeds.
- Weed ‘defensively’ by pulling up weeds before they flower.
- Keep pests off brassica and carrots by covering crops with horticultural fleece.
- Look out for early aphid attack.
- Feed with a general–purpose fertiliser.
- Apply mulch and put up supports for perennials.
- Remove flowers from strawberry plants planted after September last year.
- Formative pruning of plum & cherry trees can start once leaf buds open.
- Plant out pot-grown broad beans 6-9 inches (15-23 cm) apart, after hardening them off. Space rows 18 inches (45cm) apart.
- April is ideal to sow a wide range seeded crops directly into prepared drills, including:
- khol rabi
- swiss chard
- summer cauliflower
- broad beans
- and spring onions.
- Plant chitted potato tubers in April, starting with first earlies through to main crops at the end of the month.
- Continue planting potatoes; plant second early potatoes early in the month, and main cropping potatoes towards the end of the month.
- Plant ‘softneck’ garlic such as ‘Picardy Wight’ up to the end of April. Softneck garlic have no flower spikes and often have more cloves to a bulb than ‘hardneck’ types.
- Finish planting onion and shallot sets by mid-April.
- Throughout April continue direct-sowing seeded vegetables as listed above.
- Towards the end of the month watch out for the caterpillar-like larvae of gooseberry sawfly, which can defoliate gooseberry and currant bushes.
Sow Indoors / Under Glass
- Sow tomatoes, cucumber, celery and celeriac indoors early in the month.
- Pot tomato seedlings into individual pots when the first true leaves appear.
- Sow leeks and brassica.
- Sow chard, coriander, parley in a cold greenhouse to plant out later.
- Sow tender vegetables indoors, such as runner and French beans, courgettes, marrow, squashes and pumpkins.
Flower / Ornamental Garden
- Divide snowdrops as they die back and replant divisions singly at the same depth as growing previously.
- Remove faded daffodil and tulip flowers, leaving leaves to die back naturally.
- Direct-sow annuals such as sunflowers, California poppies and pot marigolds.
- Plant summer-flowering bulbs such as lilies, cannas, dahlias, gladiola, nerines etc
- Sweet peas can be direct-sown in April.
- To ensure good flowering, feed and fertilise roses.
- Prune forsythia after flowering has finished.
- Remove frost-damaged growth from shrubs.
- Inspect roses for black spot; remove affected leaves; use fungicide (RHS, The Garden, April 2013, p.29)
- Spray new foliage of roses against rose mildew using products with a physical action, such as SB Plant Invigorator (RHS, The Garden, April 2015, p.29)
Division & Cuttings
- Divide and replant herbaceous perennials.
- Look out for new life. April is the best time of the year to enjoy garden wildlife. Mammals (squirrels, foxes, as well as mice and all sorts) as well as amphibians, birds and insects are busy breeding and nesting at this time of year.
- Warm sunshine brings out butterflies such as brimstone and comma butterflies.
- In evenings young fox cubs may be spotted.
- Bats emerge from hibernation when night temperatures rise about 5 degrees C.
- Migrant birds from Africa to the UK can now be heard in the dawn chorus, including house martin, swallow and swift.