Offer citrus trees some TLC

19:58, Mar 03 2013
Lemon tree
ZESTY MAINTENANCE: Prune citrus trees by removing unwanted branches back to the trunk.

This is a good time of the year to do a bit of maintenance on your citrus trees.

First, have a look to see if the tree is dense with many branches coming off the trunk.

If the tree is not open, allowing a reasonable airflow through, then it's more vulnerable to disease and insect attack.

Maybe some of the outward growing branches have got too long and are now a nuisance?

If so, never trim back the branch to where you would like. This only causes more shoots to emerge from what's left of the branch. These will grow into branches even longer than it was before.

The pruning of a citrus tree is done by removing total branches back to the trunk.


The only exception to this would be with a young tree that does not have many branches and nipping a few centimetres off the end of a branch or two will promote more branches. Surplus of these can be removed from their source.

When removing branches, you need to protect the wound from disease and insect attack.

Add copper and borax to acrylic paint then paint over the sawn-off end of the branch at the trunk.

The copper is for diseases, the borax is for citrus borer and the paint is the medium for application.

Some garden centres will have one-kilogram jars of borax. While inspecting the tree's trunk and branches look for borer holes. Newer holes are likely to have fuzz (fine sawdust particles) coming out of them.

This is a good indication that you have active borer in the tree which must be treated, otherwise the tree will die eventually.

I have found a great method of treating these active holes or areas where borer are feeding and that is diluting Neem Tree Oil half-and-half with warm water, sucking the solution up into a syringe and injecting it straight into the holes.

The sap will carry the solution to where the grubs are feeding and that will stop their ability to eat so they die of starvation.

You can do this again a couple of weeks later, repeat till there is no further fuzz appearing.

Borer holes are bad news on a tree as they allow the adult beetles easy access to get in and lay their eggs. Also if the holes are there it is difficult to know whether they are new or old so it's best to seal them up.

Once again, acrylic paint with a good amount of borax added is ideal to dab on and cover the holes.

If an adult borer attempts to open a painted, blocked hole, it will get a dose of borax and die. This treatment for borer can be applied to any live tree or shrub.

While checking the tree, look for any pest insects, ants, black sooty mould or stickiness to the leaves. Any of these signs mean there are insect pests in the tree feeding so, after you have removed any branches to open up the tree, the time is right to spray.

If it's whitefly that you have then, just before dusk, spray the tree all over with Neem Tree Oil and Key Pyrethrum. Repeat this again about a week later until the pests are under control.

If it's not whitefly then spray with just the Neem Oil.

It's also a good idea to sprinkle Neem Tree Granules under the tree and out to the drip line.

This will help reduce pest problems, kill any soil insects including root mealy bug.

Repeat about every three months. neem granules are also a natural food for the tree.

Talking about citrus feeding, avoid the manmade fertilisers called "Citrus Food". Instead, use natural foods such as blood and bone, sheep manure pellets or BioBoost. I prefer the BioBoost with chicken manure. Every month sprinkle some Fruit and Flower Power under the tree to give it the potash and magnesium it needs.

If you have fruit that are not juicy and don't taste right then the tree is lacking in Fruit and Flower Power.

All citrus diseases to the fruit and foliage can be prevented or controlled by sprays of Liquid Copper and Raingard. As a preventive, this should be done twice a year normally spring and autumn but any time is fine.

Citrus trees are prone to root rots in wet weather so a spray or two of Perkfection in the autumn and again in the spring will give some protection from the diseases that comes from wet feet.

Make sure the area the tree is growing in is well drained.

Problems? Phone me on 0800 466 464 or email

The Southland Times