Garden tasks for April 2015

Flower garden

Lift gladioli corms and dahlia tubers once the foliage has died down, and store in a cool, dry place.

Plant your lily bulbs or divide existing ones. Dig up bulbs, divide bulb scales and plant in seed-raising mix.

Lift and divide daylilies.

Hurry and finish spring bulb planting — it’s your last chance!

Spray trees and shrubs with Conqueror oil to control scale, aphids and mites.

Continue with autumn planting of trees and shrubs that stand up well to winter. Leave those that may need a bit of pampering until the weather warms up in spring.

Plan new roses to plant this winter, and get the ground prepared by digging in plenty of well-rotted compost or aged cow manure.

Mulch trees, shrubs and perennials with compost.

Sow seeds of frost hardy flowering plants such as calendulas, cornflowers, primulas, stock, ornamental kale and pansies.

Plant out seedlings of wallflower, cineraria, linaria, viola, nemesia, poppies, lupin, statice, calendula, polyanthus, clarkia, scabiosa, snapdragon and stock.

Fruit and vegetable garden

MY15_garden-tasks-kale.jpgMay is a good time to plant onions, including shallots and spring onions. They like a sunny, sheltered spot in limed (slightly alkaline) soil.

Earth up celery and leeks.

Lift and divide horseradish.

Cut back asparagus to within 15cm of ground level after stems turn yellow.

Sow directly into the garden: broad beans, peas, spinach, winter lettuce, onions, radish, turnips, swede and parsley. In trays sow broccoli, cabbage and cauliflower for planting out later.

Plant out seedlings of cauliflower, Chinese cabbage, endive, kale, silverbeet, spinach, Brussels sprouts and radish.

Plant in the garden or in containers: strawberries, raspberries, gooseberries and currants.

Harvest feijoas, guavas, kiwifruit and tamarillos as they ripen.

Divide and replant large clumps of rhubarb — give them heaps of compost — they love it!

Plant citrus in a well-drained, sheltered site — they won’t tolerate chilly breezes or cold, wet feet. Feed existing citrus with fertiliser.

Spray any fruit trees that have become diseased during the growing season with lime sulphur. If we’re having a lot of rain, try to choose as settled a day as possible and add a sticker or wetting agent such as the organic Rainguard.

Treat curly leaf on peaches and nectarines — spray with fungicide just before the leaves fall and again in spring, just before the buds burst. Treat all the foliage, bark and buds with copper spray to stop the disease taking hold.

Mulch all vegetables and fruit trees with compost before the soil becomes waterlogged or cold.

Lawns

Feed lawns to boost growth and suppress weeds. Bare areas of lawn can be raked over and reseeded.

Second thoughts

Bring frost tender patio plants into a sheltered position.

The combination of cooler weather and over-watering can prove fatal to indoor plants, ease off watering and fertilising as the weather cools. Vivienne Bailley

Vivienne Bailey