citrus trees love the sun.So make sure it gets ample sun throughout the day.

Regular fertilization won't hurt.It is especially important when the soil in your pot is not fertile.you can give it some more potassium around the flowering and fruit set.

When the tree sets fruits,namely when the ovary begins to appear, it is sensitive to abrupt water changes.You should keep the soil moist and never leave it dry up completely.Be careful not to overwater it, since it may cause flower or fruit drop as well.

Make sure no infection or insects are present at this time on your tree.There are many insects that can make your tree not to set any fruit.Try and see in the area around the ovary for any possible insect there, at different times of the day.

Also if your tree has too much branches and foliage in comparison with its trunk, then this may be the possible cause of your fruitless tree.You can prune your tree, cutting the branches that grow from the center of the tree, making space for ventilation and decreasing the number of peripheral branches so as to give some strength to the remaing ones.

good luck

I have several fruit trees and have never had much success with them in pots - not many lemons were produced.

The citrus family are beautiful all year round (especially in the winter when they are covered in delicious fruits or fragrant white blossoms) but very susceptible to cold and disease. The specially selected orange and lemon varieties grown for fruit are all grafted to improve their disease resistance.

All citrus trees like moist soil but extremely good draingae - have you got any stones in the bottom of your pot or even a hole?

Standing water will kill your tree, especially if it is in contact with the trunk - I never water my fruit trees straight down the trunk - always a bit further back.

The roots of citrus trees extend beyond the outermost tips of the branches, so for watering you should scrape up two circular ridges, the first 300mm/12in from the trunk and the other 1m/3 ft or so beyond the reach of the branches.

Fill this basin every ten days from early spring to midsummer, reducing the frequency to once every 3 weeks in the absence of rain for the remainder of the year. The water should not stand for more than a few minutes so never provide more than the soil will absorb quickly.

The tree is partly dependent on surface roots so avoid cultivating too deeply within an area equal to twice the extent of the branches.

I would consider moving the lemon from the pot you have it in (if not big enough) - usually we plant in early spring to ensure that the young tree does not die out at any moment during the first two summers.

Established trees should be given a general fertilizer high in nitrogen, at intervals from late winter to early autumn.

Only apply a little at a time since a high concentration of salts in the soil will be injurious. For the same reason, citrus trees are never happy growing in coastal situations. Alkaline conditions call for the application of iron chelate. Big trees can be moved in midsummer. If you do move the tree, pay particular attention to watering!

Lemon are much less hardy than the oranges and will take very little frost, though they mind the wind less. They should fruit and flower all year round.

Hope that helps :)

We now live in an ático with a fair sized terrace and have just bought a 'lunar lemon' from a vivero, where it appeared to have been raised in a pot. These trees are spindlier and produce thin skinned fruit but ours, now transplanted to a bigger pot, looks healthy and is carrying fruit......fingers crossed.