I have been using Schultz Instant plant food on this orange tree for the past 15 years. Are there any recommended fertilizers that would help growth and fruit production? Best regards and again my thanks for any replies.
Brian, as no one has answered your post I will try to help. First, I admit that I am not a fan of Schultz fertilizers. Second, I must highly congratulate you for keeping a containerized citrus tree alive for 15 years. On average a containerized citrus tree's life span is 2 years, almost always due to the person growing the tree, and not the tree it self. Before, we talk about fertilizer, know that the average orange tree started from planting a seed in a container will take 8 to 10 years before the tree becomes mature, and begins to bloom and fruit. This can be a little longer when grown inside. Orange trees, in fact all citrus trees, absorb nutrients (NPK) from the soil in the ratio of 5-1-3. This means for every 5 parts of nitrogen the tree takes up, it will always take up 1 part of phosphorus and 3 parts of potassium (plus various trace minerals). Therefore, you should try to find a fertilizer as close to this ration as you can. Note that what ever fertilizer you purchase be SURE that it also contains trace minerals. Most fertilizers do not include magnesium (Mg), therefore you will need to supply magnesium using Epsom Salts (1-teaspoon/gallon 4 times a year). Look on the label to verify whether Mg is included or not, then take the proper course of action. I would fertilize at 300 PPM Nitrogen, at a very minimum of once a month, twice a month is better. During winter you can follow the same procedure but using 1/2 strength. What is written above is a good fertilizer plan. HOWEVER, my guess (??) is that fertilizer is really not your tree's problem. Have you been pruning this tree in any manner, no matter how large of how little ? A pruned citrus tree will not fruit, or at least it will be extensively delayed. Citrus produce blooms/fruit ONLY on new wood, therefore any pruning is cutting off the latest growth, and therefore the tree is unable to bloom. Also, at what temperature are you keeping your orange tree during the winter? In order for a mature orange tree to bloom it must receive between 600 to 800 hours of cool temperatures below 68F (minimum), below 60F (15C) is much better. If your tree is in your house during the winter, and not received enough cool temperatures, the tree will produce vegetative growth and not flowers. Hope this helps you. If you have any other question, ask. Good luck. - Millet
Brian, I notice that you asked about your tree on this and another thread. I did not associate your name with both threads. Sorry if I answered some parts of your two questions twice. Any way, I think your blooming and fertilizing questions have been answered. - Millet
i am cutting off the heat to the inside family room at night and opening a door to the outside for approximately 1 hour. The temp I achieve is abot 14.8 or 14.7 for 7.5 hours a night. This is 232.5 hours this month, January I'll do the same and February, and probably part of March. Got 4 or 5 days the end of November.This should give me more than 600 hours at less than 15 degrees. Daytime temp is 20 or 22 degrees. Light is now on 15 hours a day...There is some new growth. I will try to find some fertilizer that is better suited. Best regards Millet And again my sincere thanks for all your help. Brian
One last comment on the 600 to 800 hours of cool temperatures. A citrus tree that produced a heavy load of fruit in the previous season, will require the higher amount of cool hours to produce the next harvest. Trees that either had a light crop, or no crop at all, can do quite well with a lower number of hours (600). Take Care. - Millet
One more "last" comment. Because you are reducing the temperature, you will need to keep track of the temperature of the tree's root zone (growth medium). Citrus roots stop functioning when the soil temperature is at or below 55.4 F (13C). Therefore, if the tree's foliage is directly in the sun's ray's long enough to cause the leaf surface to heat up to the point that the leaves "call" for water from the roots in order to transpire (cool the leaves), the root will not be able respond. If this goes on long enough the tree will respond by dropping all of it leaves. Therefore, if the tree is going to set in the direct sun light (south window) the soil should be kept at 64F (18C). If the root zone is at, near, or below 55.4F (13C), then remove the tree from direct sunlight. You can read all about this by using the search function on this form . Type in the words "WLD" or "Winter Leaf Drop". As far as cool hours for fruiting, foliage temperature is independent of root temperature, meaning the root temperature can be anything. The only thing that matters is that the foliage is receiving the proper number of cool hours. Let us know how everything works out.- Millet
I got some fertilizer form Treehelp.com for citrus trees. First of all they sent pucks that are supposed to be used on perimeter of tree...not sure how to use them in a potted tree unit. Also there was Mycorrhizal Treatment for Citrus and some Treehelp biostimulant. I have used one teaspoon of the biostulant in 4.5 litres of water this past month. I am still using the temp reduction to approximately 15 degrees C each night. I curretnly have 610 hrs at average temp of 14.6925 C. This tree has never had a flower or fruit on it! What should I do now?
