Hi Tui, I have attached photos of my sad looking lemon tree. Can you give me any suggestions on what may be wrong with it. It gets sun most of the day, has had citrus food and citrus mix added to soil since planting at beginning of this year. Thanks.

Hi Aaron, plants defoliate like this due to disease or stress. It could be either too much water, not enough water, too much fertiliser, poor drainage, sudden changes in temperature - hot, cold or frost, or a disease which can be caused by any of those factors. Root rot, for example, can be caused by plants drying out, when watered they  take up too much water and the roots burst. This allows soil pathogens to enter the plant causing root rot disorders. Plants drop their leaves, as well as produce flowers and fruit to reproduce to save themselves when stressed. If the block wall is new there could be residue from the cement in the soil affecting the tree. The leaf that is on the plant looks scorched like it is sunburnt, this could be caused by too much sun coming off the block wall behind the plant or could be caused by over application of fertiliser. While it is a good position for winter, maybe it is too hot for summer. To prevent sunburn you could either move the plant or put some sort of shade cloth up behind the tree to see if that makes a difference. If you suspect over-application of fertiliser put a sprinkler on the tree for 15-20 minutes to try and lush excess fertiliser out of the soil, you will know if it is fertiliser, as the tree would have defoliated soon after feeding it? To help the tree, apply Tui Organic Seaweed Plant Tonic at a rate of 100ml per 9L watering can, apply weekly until the tree shows signs of recovery, reduce the applications to fortnightly or monthly once it recovers. Do not apply more fertiliser until late summer, early autumn, be sure to follow directions on the pack. This next step will be hard to do, but remove any fruit that has set as all of the plants energies is going into producing fruit. The Tui Team.