Heh... well, this may well be the blind leading the blind here. My references are all second-hand as well, so I have NO independent confirmation as to whether this is correct for a yuzu. What I'm told, however, is that yuzu is hardy down to ~8F, and the areas of Japan and China where it's commercially grown receive about 200-500 "chilling hours" (It's possible that this isn't necessary at all, and my tree isn't blossoming for other reasons! I'm a complete greenhorn when it comes to the specialty citrus, so my basic premise here might be incorrect.

Cut the ones touching the fence off close to the ground now. After those sprout replacement shoots, cut these off as well - to keep the shrub away from the fence. Any other major pruning you might want to do to the rest of it should be done at end of winter, cutting down to about 18 in. If you just cut back the oldest ones during occasional years, there will never be a time when the plant looks seriously whacked at. And has no flowers at all, something that will be the case for several years if the whole thing is cut low within the same period of one or two years.

I'm guestimating here and all in-ground: Ponderosa lemons...getting swamped this year with over ten bushels (wild flying guess that's probably way under estimating as I have been picking now and then since November) from ten trees that are significantly producing. About ten more young trees making smaller quantities. I juiced five gallons of juice Saturday and froze most. I tried making lemon jelly using the seeds for a source of pectin. It tastes good but didn't set up. I'm picking the fruit into a contractor-size wheel barrow and probably have another load or two left in the trees. I put a box out by the road the other day with a free sign. Folks took about half. I think I can give away another big box or two and will have to either juice the rest or let it rot under the trees. I got into this predicament because the trees come up from seed and I just transplanted trees from the compost all over the yard. Now I'm needing to thin out the herd because I'm somewhere between swamped and commercial but don't have a market or the time to go commercial. Satsumas....probably 4 bushels from two trees. I LOVE Satsumas! Calamondin.....1/2 to 3/4 bushel from one large tree. This crazy tree is blooming now! Kumquat......1/2 bushel from two trees. I eat off the tree, make a pie now and then, and freeze some puree' for later. Meyer.......1/2 bushel from one small tree. I'm picking a few now and then for recipes. Moro blood orange......32 fruit this year. Very tasty first crop and looking forward o seeing what it does this spring.

I have purchased trees from 3 different nurseries and each have different ways of grafting their trees. The trees from Four Winds Nursery have shorter trunks, but yet have full canopies. Trees from Harris Citrus Nursery have very tall trunks, but they are really thin and top heavy. Grafted trees purchased from Lowes which are supplied from Saxon, Becnel and Sons have trunks that are not too short, but not too tall. lol. The only thing you can do is wait and see how they grow. Each variety of citrus has different growth habits. From what I have read and watched on youtube, you just trim to keep the tree symmetrical as the tree grows. With any tree, as it grows taller, you can trim the bottom branches to get the trunk you desire. I supplement my trees with fish emulsion to encourage growth. I got 18" new of growth on my Eureka lemon tree in 4 months and about the same on my New Zealand Lemonade tree. My other trees didn't grow as much as these two so that tells me that it all depends on the variety of citrus. I am not crazy about my NZL's shape either as it was an entry level tree so I contacted Four Winds Growers inquiring how to prune it so it would be like their typical premium trees. My tree is growing like a V- shape. I requested it to be in video format so other people would be able to benefit from it as well. A positive response from Aaron Dillon, owner, was received before the holidays (Thanksgiving). I hope he will follow through now that the holidays are over. I have a feeling that my options are limited because of the natural growth habits of the tree which is not the fault of Four Winds Growers. It is a relatively new variety growing here in the US too so I think there is much to learn about this variety. I have not seen online a mature tree to use as a model or other young trees to compare my tree with.