In July I moved into a new house with an established lemon tree (about 4-5 m high) and orange tree (3-4 m high). Apart from collecting the last crop we have left them alone. The previous tenants grew their own vegies, so I assume the trees were cared for up until about April last year.

Today I stripped off a vine that had been growing all over them, and I wonder what care should I give them now. I assume I should get rid of all the stuff growing under them. Is it too late/early to fertilise (I'm in Sydney, so it is midsummer)?

Some of the leaves on the lemon are a bit yellow, but that might be from being overgrown by the vine.

1 Answer 1


Did the trees flower over the last few months? Do they currently have small green fruit on them? If so then you have a chance to save the current crop in which case you should definitely fertilise. Use a good quality citrus fertiliser. For trees of that size you will need to apply quite a bit. It has taken me a few seasons of caring for the established citrus trees I moved into a place with to get my head around how hungry they are. Without enough fertiliser you will get a lot of fruit drop.

If you don't have fruit on your tree now then you've missed this seasons crop so fertilising or not won't make a huge difference, but it can't hurt.

You should definitely clear all grass and weeds in the area under the trees. Citrus do not like grass etc growing in the root zone. Be careful when removing the weeds as citrus have relatively shallow roots than can be disturbed by vigorous digging. Once you've cleared the root zone, put down a goodly layer of cow manure (and fertilizer) then top with mulch such as sugarcane or lucern.

Yellow leaves can be a sign of general nutrient deficiency (lack of fertiliser) or specific lack of zinc and magnesium. First thing is to clear the weeds, mulch and fertilise. If you still have problems you can investigate further.

The other thing you probably want to do it give them a good prune. If they have fruit on them just take off the worst looking leaves and any dead wood at this point. If not, then you could take the opportunity to prune them harder, in particular opening up the middle of the tree and removing any diseased leaves (leafminer, black scale etc). My established citrus have been doing much better since I gave them a hard prune after I suspect several years of no pruning. Just avoid doing this while they are fruiting or you will lose that crop (most likely).

In general, citrus need a fair bit of TLC to keep them going well. I'm in northern Sydney and find that unless I keep up a consistent schedule of applying white oil then leafminer and black scale take over. I also get a lot of bronze sucking bugs (commonly known as stink bugs) which I remove with a pair of tweezers. Again I find that unless I go around at least once a week or so the bug population gets out of hand. Personally I'd find it difficult to give this attention to a 4 metre high tree, so I now keep mine to around 2-2.5m high. This obviously makes picking the fruit much easier as well.

  • The lemon has small fruit, the orange doesn't have anything. I cleared out most of the growth around them today. I did not dig up the grass that didn't pull up without effort, but did mow it very short. Most of the growth was actually the vine that is trying to take over everything.
    – timbp
    Commented Jan 3, 2013 at 6:18
  • Depending on how virulent the grass is, you might be able to get away with simply covering it with manure then mulch and hope that kills it. Alternatively you can hit it with some glyphosate (e.g. Roundup), wait 10 days and then manure and mulch. You definitely want to clear anything growing under the trees one way or another, short grass is still alive and growing, stealing the nutrients and water from your tree. Commented Jan 3, 2013 at 6:46
  • @Bogdanovist I assume that when you say fertilizer you mean a chemical one? Or could you recommend a natural fertilizer (as you say: cow manure).
    – Patrick B.
    Commented Jan 6, 2013 at 8:06
  • I use dynamic lifter on my citrus, which is a 'pelleted fowl manure' fertiliser, i.e. it's concentrated chook poo. There may be some additives, but it's basically natural. Cow manure is more of a soil conditioner than a fertiliser as such. It won't deliver enough nutrients on it's own to satisfy your citrus. I believe blood and bone is also a suitable citrus fertiliser and as the name suggests, it's pretty natural. Commented Jan 6, 2013 at 20:34

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