My lemon tree is having some problems. First almost all the lower leaves have fallen off. Some of the branch ends have started to turn black and die. The soil temp is at 68F and the inside of the house is at 76F on regular bases. I use Dynamite all purpose 18-6-8 + micros fertilizer. I don’t water till top three inches are dry. What could be the problem? I thought that the heat duct was making it to hot so I covered it for 3 weeks but have seen no changes from that. I had scale about 1 month ago and I use volks oil to get rid of them, but it looks like it changed some of the leafs, you will see in some of the pic’s the green splotches.
volks oil or any Horticultural oils if not mixed properly can kill your tree. More of the advanced members may suggest using them. But do they give you the heads up.. Take you tree to the bathtub and hose it down good, replant in a fast soil mix, keep the root at about 70F-21C and hope for the best.
Horticultural oils when applied properly are very safe. The correct spray solution is made of 1 percent oil and 99 percent water. When using a horticultural oil never spray during the heat of the day. Spraying in the early evening is the best time of application. Horticultural oil are the number one "insecticide" used by the citrus industry. Washing down a citrus in the bath tub or kitchen faucet, normally does not cause the tree a problem. However, it all depends on the soluble salts in your local water. Each time you wash the tree the leaves absorb the soluble salts. Repeated washings over a short period of time will cause leaf drop. I notice your tree is setting in a drip tray. You either must get rid of the tray, or be sure that you do not let the container set in the drain water, by emptying the tray after each watering. From all the information you have supplied in your post, you are doing most everything correctly. I do have a couple questions. (1) How long does the soil remain wet after you water the tree? (2) How long has the tree been in the same soil? (3) what type of growth medium is the tree growing in? (4) how fast does the water pass through the container when watered? The heater vent that is next to the tree, is it blowing air out, onto the leaves? - Millet
(1)How long does the soil remain wet after you water the tree? I takes about 3 to 4 weeks before the top 2-3 inches gets dry. (2) How long has the tree been in the same soil? I just purchased it about 4 month ago. Where can I get a root maker container in 5 or 7 gallon from? Is there a place to get CHC that are pretreated with no soluble salts? (3) What type of growth medium is the tree growing in? It is growing in some kind of bark and sand mix. PS I empty the tray that it is sitting on a couple of times after watering. (4) How fast does the water pass through the container when watered? It takes just a second to pass through. (5)The heater vent that is next to the tree, is it blowing air out, onto the leaves? It is a radiant heater vent so the tree does get some heat from it.
To start with, your tree does not look all that bad for a Meyer Lemon. On the citrus forums Meyer Lemons are the number one variety that people ask for help with tree problems. To answer your questions. (1) 4 weeks is a rather extended time, but not excessive for this time of year, for the growth medium to stay wet. Shorter would be better. (2) Root Maker containers are in my estimation the absolutely BEST CONTAINER that you could grow a citrus tree in. Their web address is www.rootmaker.com. I believe they have a $50.00 minimum order. The only company that I am aware of the sells pre-washed and pressed CHC is The Crystal Company of Saint Louis, MO Telephone number 1-800-845-4777. You will still have to soak the chips in a solution of Epson Salts and Calcium Nitrate for an hour or so. I One ounce of each chemical per 5 gallons water. (3-4) Sounds OK. (5) I am not 100% sure what you mean by a radiant heater vent. I do notice that the missing leaves are the leaves closest to the vent. I also notice that a couple of you new leaves at the top of the tree have dried up and look dead. New citrus leaves transpire many times faster than do mature leaves. Therefore new leaves desiccate much more quickly and easily that do mature leaves. I guess is the radiant heat is what caused the new leaves to become desiccated, as being near the heater, the leaves lost water faster that the root could supply. My Meyer Lemon (4 feet tall, in a 5-gallon CHC medium) started to drop some leaves a couple weeks ago, so I raised the root zone up to 86F and the leaf drop completely stopped. 86F is the OPTIMIUM root temperature for citrus roots. I don't think your soil has a soluble salt problem from the looks of the leaves still on the tree. I would say the problem is with the heater, and or the length of time that the soil stays wet. Does the trees growth medium contain a lot of peat moss, or has the bark chips degraded? If you have a heat mat (must be water proof) you can set the temperature to what ever temperature you wish. In my estimation, the easiest citrus tree to grow is a Satsuma. - Millet
