Sheena,
You appear to have been left out in the cold! Maybe aphis on your lemon which you can wash off with a strong hosing or use Pyrethrums or 'Confidor' and read & follow packet but DO NOT USE 'Rogor' on lemons cause it will defoliate the plant rapidly. See if you can stop the ants climbing the tree and farming out the aphis. That involves some 'heavy' chemicals.

Maybe leaf miner which leave silver trails in the leaf. Spray with 'white oil' late in day but this also kills the good insects and drowns the air inhalation of your lemon. Leaf miner makes the plant look awful but is only a minor (hic) handicap. Maybe do nothing and enjoy your lemons.

Fertilize with citrus tree fertilizer ( I use Nitrophoska blue) NOW @ 125 grams (= 4 handfulls) per year of age to a maximum of 10 years. Sprinkle around the dripline of the outer canopy. Do this again in November and January.
Goodluck. Sweeney

Sidenote, which i learnt the hard way: dont use white oil on plants that are in full sun, and especially not in Summer. The key word is 'oil'. It can boil off at quite a low temp and this fries the plant (goodbye nice lush window boxes). A new-ish stuff called 'plant spray' or 'plant oil', mental blank right now, is a similar oil but has a much higher boiling point so you can use it in the warmer months.
scott. :-)

get 3 handfuls of FRESH compost- not too aged, as the bacteria must be alive. put the compost into a panty hose, then into a bucket of water(rain or tank water only- as tap water will kill the bacteria) soak the compost in the bucket for a week minimum.
Pour the compost TEA(because it LOKKS like strong tea- it DEFINATELY doesn't smell like Liptons!!)into a spray pack( thru a strainer or another panty hose to prevent solids blocking your spray jets.
Spray over your tree, and LEAVE it on for as long as possible, without rain washing it off.
The bacteria are the secret weapons here, they have been know to kill many pests and diseases on a variety of plants- alos roses, camellias, azaleas, passionfruit and grapes- any hard leaved foliage( NOT Palms or ferns etc)

Here is a link that might be useful: YUCK!- Organic Quality Compost Mulch

I have been left a little confused here. I have a lemon tree in full sun with 'leaf curl' and 'silver miner'. Sweeny said to spray with white oil but Scott said not to. What do I do to control these unsightly pests? Any help would be appreciated

Thanks Cassie.

Hi Cassie
I have used white oil in the middle of Qld summer, on plants in full sun with no problems.
Bev.

Dear Sheena, I've only just seen your question so this reply might be a bit late considering we are now in winter. I have had this problem on my lemon, orange and mandarine trees previously.
You can trim off the effected leaves and then spray with pest oil, I found this effective. I have also had to use folimat and confidor this autumn for aphids. I found the folimat to be more effective.
The pest oil did work well. You may also be able to spray the white oil as a preventative, if in doubt read can instructions.
good luck, michelle.

I learnt the hard way! Clear white oil kills plants as it burns the leaves. The Lemon tree seems to cope well with it but I am sure it's no good! Even in cold day, clear white oil will penetrate and stay there just waiting to kill the young leaves. The clear white oil I tried a few days ago almost kill all my roses! I want to kill the manufaccturer for mentioning the use of it on roses and also gave a dose. So I thought it was safe! This is a murderer!

If you look for a product called "ANTI-SCALE" which has white oil content. This one works. It is a different type of white oil that make the water become very misty and it disolves completely into water. Therefore it will not penetrate the leaves and burn them in warm day. ANTI-SCALE has a very strong smell. It comes in a glass bottle. So if you want a chemical, go and look for this one. The label has picture of bugs and scale on it. It smells like cockroach sprays.

Wetting agent removes the protective coat from scale and they will die from that alone as will aphids. I usually use 1 cup of Lux Flakes (pure soap) and disolve it in 1 ltr of boiling water to make a jelly which I then mix with a further 4 ltrs of cold water. An addition of 30grms carbaryl mixed to a paste and 2.5 mls lebaycid or 5mls rogor to this soapy water makes a lethal spray. It's a very deadly mix and kills just about everything living. So protect yourself properly. IMO the mix should only be used 'in extremis' but when the need arises it will do the job very efficiently. HTH teddy,J

Hi
I was wondering if anyone could help me. I have a lemon tree and have recently noticed the leaves fading in colour and also little brown spots apprearing on the leaves. Does anyone know what this is or what i can do to fix it? Any help would be greatly appreciated. Thank you

I am using confidor for Lemon and pomgranate tree it is best for Leaf curl

How effective Liquid Copper Fungicide is to prevent and control leaf curling??

New growths are showing signs of curly leaves. Flowers & fruit are forming. Should we spray or trim? Please advise

Fertilize well, trim the dead wood (not the TV series)This should do the trick, and as far as ants harvesting aphid sugars,try to remove low branches and keep long grass away from the tree as this alows ants a way of getting into the tree. Once this is done smear grease(vasoline) around the trunk this will stop the ants climbing. Now spray with white oil,works a treat and is amusing watching the ants trying to work out what is going on.(tricked them) This helps prevent sooty mould on your citrus. Works for me.

I have a dwarf lots o lemon tree in 50% sun all the new
growth is infected with leaf curl the tree is in it's
first year of fruiting, how can i stop this pest?

MY LEMON TREE DID HAVE LEAF CURL WHITE OIL DOESNT WORK NOW
ALTHOUGH IS FRUITING IT IS LOOSING MOST OF THE LEAVES. WHAT CAN I DO TO SAVE IT? WE DID HAVE A LOT OF RAIN THIS YEAR AM I
LOOSING MY LEMON TREE? OR CAN I SAVE IT.
THANK YOU

My citron tree is an indoor one, several years old.
It lost 75% of its leaves before I was told it is scale. I sprayed with soapy water and also diluted white oil. I fetilized it as well. The pot is about 35 gallons in volume, and the tree stands about 7-8' high. I keep up with the scale, put cannot rid it entirely. Many leaves are yellowing, also curling. Some to have brown patches.
I misted the tree heavily with water to rinse off any dilute soap residuer. New leaves are forming, and some flowers, but some of the new leaves just dry up.

HOW CAN I SAVE MY TREE?!!

Treat the soil? Keep spending 45" a day picking off scale insects?
Would an overwater cause a sudden massive leaf drop, or a change to hotter weather? The tree cannot be taken outdoors and is in a northern exposure (not good, I know).
Should I buy lights?

Please help.

What is the best time to spray orange trees?

When they look as though they are being attacked. Check the trees for scale insect, leaf miners, citrus gall wasp, stink bugs. If you see them, time to spray. No need to spray otherwise. Oh, and I would never spray if fruit is about to ripen.