How much sun does it get in a day? The fact it only has top growth and no flowers makes me wonder if it's getting as much as it needs, but it could just be a "lemon", and/or in the wrong soil. I'm not sure if chopping would help or not without knowing more.

First about the flowering - from a couple of my other posts to different threads, so excuse that they might seem slightly OT:

To a certain degree, the flowering of all (perhaps I should hedge and say nearly all) plants is dependant on tissues reaching a certain ontogenetic age before tissue differentiation into flower structures is possible. Ontogenetic aging is roughly a measure of the number of cell divisions that must occur before flowering. It varies from plant to plant. An illustration of its influence can be seen in the fact that plants propagated from cuttings invariably flower/fruit sooner than plants of the same species from seed. The tissues in the cuttings have seen many cell divisions and are ontogenetically older than tissues from seed, thus they are capable of flowering sooner. It is interesting to note that cuttings taken from basal portions of a plant are more vigorous because they are ontogenetically younger than cuttings from top branch tips. However, the cuttings from the ontogenetically older wood at the upper parts of the plant will flower sooner.

Sexual maturity and to a fair degree, the stage of genetic vigor, are determined by the ontogenetic age of tree organs. We tend to think of the age of plants in the same manner we think of age in humans or animals - chronologically. We, like plants, go through several life stages - embryonic, juvenile, adolescent (intermediate in plants), and mature are stages roughly mirrored in plants. Where we vary greatly is in the way our cells age.
In animals, body cells all mature at approximately the same speed. Plants grow by consecutive divisions of cells at the growing points (meristems), so their various parts are different ages (the top of the plant is younger than the basal portion, chronologically). So, if the plant has reached a sufficient age to have mature tissues, vegetative cloning can occur from 3 of the 4 phases I listed above (embryonic excluded for the purpose of what I'm talking about). So, the age of cloned plants is not the chronological age of the parent plant, but the age (or phase if you will) of the portion of the plant from which the cutting was taken.

If you have foliage only at the top of the plant or branch ends, odds are your plant is likely to be extremely root bound and/or N deficient. I would make sure I do a thorough repot in the spring & allow the plant to grow unimpeded next year in preparation for a chop or hard pruning that will force back-budding in the subsequent year. How well a tree responds as far as back-budding is concerned depends on the species, of course, but also to a very large degree on the amount of stored energy the plant has when you cut it back. Therefore, good vitality and timing are essential if the outcome is to be favorable. If your tree is stressed from tight roots and weak going into winter, it will be weak in spring & respond in fashion to a trunk chop.

You need to build energy before doing anything radical, then allow the tree to recover before undertaking the next major step.

Al

He DID start the tree himself from a seed 15 yrs ago - no cloning or cuttings involved.

Oh ok, nitrogen difficient it must be! Ive been feeding all of my plants Miracle Grow Bloom Plus which I think is heavy on the phosphorus side and low in Nitrogen. Shallow pot maybe but I can throw it back in the ground for quicker recovery. I feed this because I also have a Washington Hawthorne that has never flowered and its 30 years old.It sends out 8-10inchs of growth even with this fertilizer!!

I realize he started the tree from seed. I mentioned the info might be a little off topic, but I left the part about cuttings in to illustrate the difference between chronological aging and ontogenetic aging. His tree would have to progress through all the growth stages before it can flower (become sexually mature), while a cutting from an older plant might already be sexually mature.

CV - I can think of no case where bloombooster fertilizers would be appropriate for use on containerized plants. Plants use about 6x more N than P, so even 1:1:1 ratio fertilizers like 20-20-20 provide almost 3x as much P as the plant can/will use in relation to N; after applying a factor of .43 to the P content because P is actually reported in fertilizers as P2O5 (phosphorous pentoxide), which is actually only 43% P. The ACTUAL %s of NPK in 20-20-20 would be about 20-8.5-16.5. K, as reported, needs to be adjusted by a factor of .83 to get the actual K %.

Plants use nutrients in an ACTUAL ratio of about 10:1.5:6. 3:1:2 ratio fertilizers like 24-8-16, 12-4-8, 9-3-6, come closest to actually supplying nutrients in the ratio plants use them. It's up to you if you want to employ a strategy that limits N., but if you do, you should be thinking something like a 2:1:2 ratio.

Having nutrients in the soil the plant cannot use is as bad as a deficiency. It unnecessarily contributes to the EC/TDS of the soil solution and makes it more difficult for the plant to absorb water AND the nutrients dissolved in the water. In the case of excess P, it raises pH unnecessarily, but more importantly, it can cause antagonistic deficiencies of (particularly) Fe and Mn, as well as other nutrients - mainly the secondary macronutrients and all the minor elements.

Al