Hi, I live in central California and "inherited" a Meyer lemon tree. It is slightly odd, as the main trunk was cut down and two fruiting suckers now make up my "tree". It is infected with scale and thrips. But, since it's over 100 degrees almost every day, how do I deal with these pests without damaging the tree? Also, what is the proper amount of water I should be giving a mature lemon tree? Thank you.
You can't use oil if it is over 90, so you are left with soap or pesticides. There are several pesticides with very low toxicity, like synthetic pyrethroids. Spinosad is considered natural and has very low human toxicity, but I don't know how effective it is on scale. As for water, I don't know your soil and climate, but here we have sandy soil that does not hold water and I consider it risky to water once a week--I only do that on my inground trees during fruit filling time between bloom an the end of June to reduce June drop. I have gone more than a month without watering my lemon tree and it did not show any sign of stress. Overwatering will kill much quicker that lack of water. Try checking the soil to see that it is dry at least a couple inches deep.
Thank you for your reply and advice. My soil is heavy clay and the climate is hot, especially right now. What signs should I look for with over or under watering?
The problem is the symptoms are the same because the ultimate problem is the same-- the tree leaves do not get enough water once the root rot kills a significant portion of the roots from overwatering. One way to tell is that a dry soil condition should exist for several days before symptoms appear if it is from underwatering. An established inground tree rarely need watering for the sake of the tree--although I do water my mature trees once a week between bloom and the end of June to reduce fruit drop. You can also check the soil to see that it is dry at least 2-3 inches down. If there is any fresh tender growth, it will droop slightly when it is a little too dry. If in doubt wait a day and then water. Your heavy clay soil will hold water better than my sandy soil.
How old is your Meyers? If your not sure tell me the height, and the approx. size of the trunk just above the soil line. You said it was "inherited" so the history may be a bit hard, Has it always been in the ground at this location or replanted to it's new location, has it been growing in a container. I need more information.
skeeterbug: Thanks for your reply. Okay, well, I was told not to water the lemon until its leaves droop since it is mature. I was watering once a week, but found out that it was too much and stressed the tree out. I think that the stress allowed the scale and thrips to attack so severely. drichard12: I believe the tree to be between 15 and 18 years old. The problem is, the main truck was cut down and two fruiting suckers came up to become the "tree" I have now. It is 90 inches from the base of the trunk to the uppermost branch. One trunk diameter is nine inches, the other is seven inches. As far as I know, the tree has been in the same location, but I can't say for certain as I wasn't the one who planted it. The tree is in the ground in a sunny location in the lawn, though I dug all the grass from directly under and around the tree out. I will try to attach a photo of the tree as soon as possible.
My Lemon tree is only 4 or 5 years old and we have sandy soil that does not hold water. I have not watered my Lemon tree at all for 2 years now. I have not seen any sign of stress from lack of water eventhough last summer we were over 25 inches below normal --(we have been pretty close to normal this year.) The 2 trees I watered once a week did not show any sign of stress -either from lack of water or too much, but I do think it helped prevent fruit from dropping during the dry spell we had in April and May. I have 2 other trees inground that have been watered a few times this summer, but they are only 2 years old and do not have fruit.
