Caring for Citrus – Wally Richards
Citrus trees are valuable plants for anyone’s garden, not only will they supply you with a bounty of fruit every year; they are also an attractive, highly scented tree. In fact I cannot think of another fruiting plant that has such a delicious perfume when in flower. Citrus trees are a long term, fruiting tree that you have to have a bit of patience with, for the tree to reach a good size and then you have 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 that they have a citrus tree which they never provide these requirements for at all and the tree looks healthy and green, producing ample fruit most of the year. I have seen such trees and can only assume that their roots have tapped into a good supply of food and moisture, underground and need in the time being, no help from the gardener.
Maybe it is as a result of not using any citrus, water soluble fertilisers and that the soil life is therefore in abundance, making all the humus and food the tree needs. Water soluble fertilisers kill the soil life creating the tree’s dependence on these chemical foods for its sustenance. A tree that is thus dependant will often have problems of disease and pests requiring rescue sprays and protection spray programs. It is a fact, we can cause the problems and then pay for it.
“Citrus trees hate wet feet and will kill them for prolonged periods of rain if the soil is not free draining.”
I have seen mature trees that have survived years of life 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 free draining soil where it is very sunny and yet some protection is offered 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 plastic rubbish tin that holds about 70 to 100 odd litres.
With a saw drill, drill 50mm holes in the base of the container and on the sides up about 12cm and 25 cm from the base. The number of holes should be 5 in the base (one in the centre and 4 at the cardinal points nearer to the bottom rim) at the 12cm level drill 4 holes which will be in the middle of where the cardinal point holes are at the base.
At the 25 cm level 4 holes that line up to the cardinal base holes.
You 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. I have 3 citrus thus growing in an area that gets really wet in the winter and they are all doing well after about 9 years in this area.
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 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. Back fill 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 back fill.
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. Drenches of MBL and Mycorrcin to the soil occasionally and spray to the foliage of the same.
An annual sprinkle of Rok Solids and Ocean Solids around the root zone for additional elements completes the program.
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 and spider mites and a couple of sprays of Neem Tree Oil should fix them.
Mealy bugs also, along with some Neem Tree Granules in the root zone to take out the ones in the soil.
Citrus borer are a problem but these can be controlled by soaking some Neem Tree Oil (not diluted) onto a strip of felt and wrapping it around the trunk.
Place some plastic food wrap over the felt and pin it in place with drawing pins.
(It is also a great method for control on rhododendrons and camellias for thrips.)
Sprinkle some Neem Granules over the root zone that will help too in both cases.
Another point with Citrus, if there is any chance of your existing trees getting wet feet, then a couple of 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 in winter.
Keep the mix on the dry side in winter.
If you purchase citrus that are supposed to be fairly free of pips then do not plant a lemon tree anywhere near them as the cross pollination will make your pip free fruit full of pips.
A couple of years ago my workplace planted a small garden with lemon, orange and 2 mandarins as well as a couple of feijoas and grapes. Last spring the lemon tried to grow but all of the leaves fell off after showing distinct symptoms. This year the lemon started off growing ok, but then the same happened, and the problem has spread to the other citrus, and even one of the feijoas and the grapes look a little odd. The leaves on the citrus have curled up and wrinkled. There are black ends which look burnt. They are starting to fall off the trees. It looks like a virus possibly – no sign of any fungal growth. Other option may be poison in the soil as the area was used by council including pests & plants department. Have you any ideas on what it could be?