Let’s avoid overcrowding
Ornamentals
Lift and divide crowded hostas. (This may also be done in spring.) Use a sharp spade to divide clumps of tough, fibrous roots. Ensure each section has about five or six shoots. Those cultivars with loose, fleshy roots are best teased apart by hand, or insert two hand forks back to back into the clump and lever the clump apart. Replant the divided sections at their original depth, keeping the shoots above the soil surface.
Put the ornamental beds to bed for the winter by mulching them, and around shrubs, with compost and peastraw.
Weeds are still germinating. Getting them early is always recommended, no matter the season, but in the cooler weather they may not die off on the soil surface as they do in the warmer months if the soil is damp. Removal is often best otherwise they can reroot and grow again.
Sprinkle lime around the whole garden, avoiding azaleas, camellia, daphne, erica, gardenia, Japanese maple and rhododendrons which are acid lovers.
Plant trees and shrubs, while they are in or entering dormancy, and remember to keep any newly planted ones watered.
Get citrus ready for winter
While kumquats and meyer lemons can cope with a light frost, most citrus crops will sulk and even die if the temperature drops below zero, especially in their first few years.
Find the frost cloth in the garden shed now, so it’s ready to drape over citrus trees on clear, still nights.
For young citrus trees it’s worth building a frame to cover the whole tree if you are in a frost pocket. Frames should be big enough to hold frost cloth above foliage without touching it so a layer of air acts as insulation.
If a frost threatens and you don’t have frost cloth on hand, improvise with sheets of newspaper pegged to the outer branches.
Edibles
May is really the last month in all but the warmest parts to sow greens for salad and the pot.
Plant seedlings of leeks and brassicas, though time is running out for brussels sprouts.
Sow broad beans in well-drained soil enriched with compost in double rows, 20cm apart and with beans 10cm apart.
Plant garlic and shallots, any time until early spring, with pointy end up, half the bulb deep about 10cm apart in rows about 40cm apart in free-draining, friable soil in a sunny spot. Planting early means harvesting earlier in summer so plants are less susceptible to rust.
Feed fruit trees and bushes by piling a hefty dose of compost around their bases (but not touching the trunks), then a thick layer of organic mulch.
Prune apples, pears, currants, berries and grapes.
Investigate growing nuts. Almonds and hazelnuts are not large trees so are suitable for urban life, while chestnuts, macadamias, pine nuts and walnuts ultimately need more space than an average section can happily offer.
– compiled by Barbara Smith