The parrots arrived this morning. The bower birds will be next, but Rosie wallaby has already helped herself to every ripe cumquat within reach. The birds will have to settle for the fruit that's out of wallaby reach.
Rosie understands what most gardeners don't realise: the small round orange berries sold as 'cumquats' or 'Australian cumquats' are usually sour calamondins, not cumquats. If you choose the correct cumquat variety, they are sweet and tangy. You can eat them whole, skin and all. Pop them in your mouth as you pass the tree, or split them into segments to eat daintily. Tell kids they're 'orange lolly bushes' to encourage snacking.
Cumquats begin to ripen in autumn and brighten up dull winter days. Canberra needs more of them. The fruit almost glows within dark green shiny leaves. The trees are supposed to grow to three metres high, but in our climate you're more likely to get a neatly rounded bush about a metre wide and twice that height, with no trimming needed. Cumquats also have small, tactful root systems, and are unlikely to send roots into a crack in your water or sewage pipes.
Cumquats make excellent hedges, and are ideal for a potted fruit tree. On the other hand, I've never seen a potted cumquat with the shiny, dark green leaves that indicate good health and proper fertilising, except for the two that turned out to be artificial outside a hotel in Melbourne.
Like all citrus, cumquat leaves quickly turn pale or even yellow if they need tucker. A poorly fed apple tree won't make its hunger obvious - you'll just have few apples, all on the small size. An underfed cumquat looks dismal, as will one infested with scale or woolly aphids. See pest control advice below.
Feed cumquats in early to late summer, after fruiting - fertilising when the fruit is on the tree may lead to puffy skin and too much white pith. Slow-release pellets are the easiest for potted trees - too much fertiliser at once will burn the roots.
We have two cumquat trees, an oval Ngami with sweet fragrant skin and sour flesh and a round Meiwa, with few seeds and sweet flesh and skin - you can munch the whole thing. The Marumi variety looks like Meiwa, but it's sour and thorny.
The Ngami is an excellent decoy to keep the birds from the orange trees - birds prefer small, sour fruit. Meiwa cumquats can be sliced, skin and all, into salads or fruit salads. All cumquat varieties make superb marmalade, so high in pectin it's almost impossible to fail unless you overcook it to toffee stage. Cumquat chutney is also excellent, though I don't think there is any edible fruit that can't be turned into chutney.
If you have more than you and the birds can eat fresh, cumquats are probably best candied. It's pretty easy: boil them whole for five minutes, then pierce the skin half a dozen times with a skewer. Now simmer them gently in a syrup of one cup sugar to one cup water till the skins look almost transparent, about 20 minutes. Store in their syrup, or leave them on a rack to dry, then keep in a sealed container in the fridge for up to three months.
'Dried' candied cumquats make superb cake decoration, or add them when you're making biscotti. Cumquats in syrup tend to ooze a bit on top of a cake. Add them whole or sliced to cake or muffin mixture, syrup and all, for an excellent 'very orange' flavour, or use the syrup to marinate the cake layer in a trifle or tiramisu. Add cumquats and their syrup to brandy or vodka to make an excellent and striking-looking gift. They're also a good addition to mulled wine, as a base for baked custard, or simply served with ice-cream or yoghurt.
These days our cumquats trees' main role is entertainment. The parrots hold the fruit in one claw as they try to get to the seeds, or perform gymnastics attempting to pick a dangling one. The bower birds fly off with them, but drop them half the time. Most of the fruit I bother to pick becomes a boomerang gift for marmalade makers. We provide the fruit, and now and then a jar of marmalade ends up in our letterbox, brightening winter even further as Bryan spreads it on his toast.
'Scale' looks exactly like its name: tiny scales on leaves and new branch growth. Woolly aphids are tiny tufted pests on the trunk or established branches. You'll find them on many kinds of fruit trees or ornamentals like roses, but citrus seem particularly susceptible.
Both pests are sap suckers, but it's the toxin that helps them liquify the area where they feed that does the most damage to the tree. The sweet excretions of sap suckers also host sooty mould. Often the tree owner only notices the mould, not the pests - or the ants that bring them.
Ants 'farm' scale and woolly aphids, stroking them with their antennae to 'milk' a drop of sweet sap. As one area dies the ants move the pests to a new spot. They even scare off the native wasps, hoverflies and other predators that would otherwise control the pests.
Thankfully ants are relatively easily kept off citrus trees and single-trunked rose bushes. You can buy commercial 'tree banding grease' barriers to stop ants climbing the trunk, or make your own out of something smooth, like wide black tape wrapped around the trunk, with something sticky over half of it, like Vaseline . The ants shouldn't be able to get a foothold on the slippery tape, and any that do will get stuck in the jelly. Don't apply Vaseline directly to the bark, as it can damage it, and change the band once a year so it doesn't ring bark the tree as the trunk gets larger. There are many old gardening recipes that rely on mixing dripping with various noxious substances to stop ants coming any further. They probably work, but aren't safe experiments for the backyard.
Once you've stopped the ants, use a commercial oil spray to suffocate the pests already there, or scrape them off with your fingernail or an old toothbrush. Wipe off the sooty mould with a sponge, though without more sweet sap it will eventually flake away.
