Citrus trees are valuable plants

Citrus grows well if you look after it.

Citrus trees are valuable plants for anyone's garden, not only supplying a bounty of fruit every year, they are also an attractive, highly scented tree.

Citrus trees are a long-term, fruiting tree which needs patience for the tree to reach a good size before having ample fruit to harvest every year.

We tend to stress the need for ample food and moisture for citrus trees, but often gardeners will say they have a citrus tree for which they never provide these requirements and the tree looks healthy and green, producing good crops.

I can only assume their roots have tapped into a good supply of food and moisture underground.

It could be as a result of not using water-soluble fertilisers which kill the soil life, creating the tree's dependence on these chemical foods for its sustenance. A tree that becomes dependent will often have problems with disease and pests.

Citrus trees hate 'wet feet'. I have seen mature trees succumbing to root rot in a particularly wet winter or if there has been a change of water run-off due to alterations on a property.

The ideal planting place for a citrus is in very free draining soil where it is very sunny and yet has some protection from prevailing winds.

If you have a wet area where you wish to grow a citrus tree then you can do what I have done in the past, plant the tree into a plastic rubbish tin that holds about 70 to 100 odd litres.

Drill five 50mm holes in the base of the container (one in the middle and four at the sides), and on the sides drill four holes up about 12cm from the base, inbetween where the base holes are.

Dig a hole in the desired spot, deep enough to bury your plastic rubbish tin half into the soil.

The holes you have cut will allow the roots of the tree to grow out into the surrounding soil in time, yet much of the tree's roots will be above the ground level, inside the container, and these roots will not get too wet at any time.

A big plus for this system is that if you move house you can lift your citrus trees with relative ease and take them with you. The trees will not get as big as ones planted in open ground, which can also be an advantage for smaller sections. The disadvantage of containers is the trees take a bit longer to produce good size crops.

If using this method, fill the container to planting height with a friable compost and top soil mix, (two-thirds compost and one-third soil mixed well together). Place sheep manure pellets, blood and bone and a sprinkling of Epsom salts on top of the compost. Place the citrus tree removed from its nursery container on top of this.

If the roots have become a mass, with spiral roots at the base of the nursery container then with a pair of secateurs cut the spirals at the cardinal points about 20mm deep. This allows new roots to develop quicker.

Backfill the sides with the same mix ending up with the base of the trunk about 6cm from the top rim of the container. This makes it easy to water in the summer.

If planting into existing soil, dig a deeper and wider hole than needed and use a similar mix of compost and soil to line the hole and backfill.

What food to feed your citrus?

I give my established trees a good dose of old chook manure, in the spring and later in summer along with a monthly sprinkle of Fruit and Flower Power, plus drenches of MBL and Mycorrcin to the soil occasionally, and sprays of the same to foliage.

An annual sprinkle of Rok Solids and Ocean Solids around the root zone for additional elements completes the programme. You can give them sheep manure pellets and blood and bone as an alternative to the chook manure, applied spring and autumn.

Cover the products with a layer of good compost then water in with the MBL and Mycorrcin.

A healthy citrus tree should be free of disease problems but if a disease appears, give the tree a couple of sprays of Liquid Copper. Pests can include scale, aphids, white fly, spider mites, mealy bugs and citrus borer.

All pests are easily controlled with applications of Wally's Neem Tree Granules about twice a year. Sprinkle some Neem Granules over the root zone from trunk to drip line.

Another point with citrus, if there is any chance of your existing trees getting wet feet, then a couple sprays of Perkfection in the autumn will help prevent losses. Lime trees are the most difficult to grow in cooler areas so in these areas grow them in a container above the ground so they can be moved to a sheltered frost-free area.

For gardening problems ring me at 0800 466464 (Palmerston North 357-0606) or email wallyjr@gardenews.co.nz
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