Home grown: Lemons
The plant that gives Garden Clinic gardeners more grief than any other is the lemon.
Here’s how to grow gorgeous lemons.
Words: Linda Ross
Growing lovely lemons doesn't have to be loathsome.
Don’t even consider a lemon if you don’t have a spot with at least six hours of sun a day. Choose either a full size tree, up to 4m, or a dwarf variety, perfect for pots or garden. There are three common lemon varieties in Australia:
‘Eureka’ - two or three flushes of fruit a year. Dwarf varieties do well in pots, growing 2-3m high and wide. Needs protection from frosts.
‘Lisbon’ -one major flush of fruit in winter, spikes on the stems. Needs protection from frosts.
‘Meyer’ -less acidic and popular for its small, round juicy fruit.
Search for a young, small specimen with healthy green leaves. Check the graft union - the area where the rootstock and the productive lemon join. If the plant has any suckers below the graft point, put it back and choose another as you’ll spend way too much getting rid of suckers, which can take over the plant entirely. Ensure that dwarf lemons are grafted on to the dwarf root stock ‘Flying Dragon’.
Lemons are very hungry plants, so dig well-rotted compost or old manure into the planting hole. Dig a hole twice as wide as the pot and a good depth. Fill the hole with water and let it seep into the surrounding soil before planting, and watering well again.
Remove flowers and fruit from young trees, as they take too much energy from the plant while it is trying to establish. Allow trees three years before setting fruit, then get set for bountiful harvests!
Prune from late winter to early spring. Young trees should be pruned to establish a good shape. Remove any sprouts or weak limbs so the plant can focus on growing a strong canopy.
As the tree grows, prune any crossing limbs, tangled branches or dead wood. Main scaffold branches should be staggered. Aim to maintain eight once the plant is established. Prune subsidiary shoots off these scaffold branches. Aim to prune 20 percent of the canopy each year, focusing on longer, protruding branches that affect the desired shape of the canopy. Thinning out of branches as the trees age allows light to penetrate more areas of the tree encouraging fruit production inside the canopy.
The main pests are aphids; waxy, brown scale on stems and leaves; and citrus leaf miner causing silver trails and twisted leaves in young foliage. Spray with Eco-Oil. Stink bugs may appear in large numbers from October. Knock them off the branches and squish them underfoot, but wear protective goggles as then bugs can squirt a painful liquid into the eyes.
A black crusty coating on the leaves and fruit indicates the presence of a sap sucking insect. Treat the insect pest and the sooty mould will clear up by itself. The mould is not harmful; simply wash it off fruit.