Prune Chaenomeles (ornamental quince) and Forsythia after they have finished flowering. Check roses for black spot, remove any infected leaves and treat with a fungicide.
Cut back Penstemons. If Cotinus and Sambucus are grown mainly for foliage effect, rather than flowering, they can be cut back now.
Evergreen shrubs such as Choisya, Brachyglottis, laurel and Photinia can be renovated now. Dead head daffodils as the flowers die.
To encourage bushy growth on Marguerites, Pelargoniums and Fuchsias in the greenhouse, pinch out the tips. Check for aphids on plants in the greenhouse and garden.
Hang up sticky traps in the greenhouse or wipe aphids off with your thumb and forefinger or use a spray containing bifenthrin or pyrethrin.
Spray weeds on driveways and paths this month when they are actively growing. Use a spring/summer feed on the lawn (it should be high in nitrogen to encourage strong leafy green swards).
Borders can be fed with a general purpose fertiliser, then mulched with compost or well-rotted manure.
Autumn sown sweet peas can be planted out now. April is an ideal month to sow a wide range of vegetables directly into prepared drills, including carrots, turnips, peas, broad beans, spinach and lettuce. Second early potatoes can be planted early in the month, and maincrops towards the end of the month. Protect new shoots from frost.