Avocado With Single Fruit

Question from Kathy:
Just discovered your useful website and hope you can help me. Our back yard has an avocado tree that was planted before we bought the house, so it’s probably 10 years old. It has never fruited,so we considered it mainly ornamental and a source of shade. Imagine my surprise to see a one large fruit hanging from it a couple of weeks ago. I picked the fruit and brought it inside where it ripened in about a week and was the best avocado I’ve ever tasted! Don’t know the variety – fruit was a large oval, about 5 inches long,4 in diameter, medium green smooth skin, and pale very creamy and flavorful fruit. My question – how can I encourage more fruiting? The tree’s loaded with blooms now, so it’s probably time to do something. Do I need to bring in another tree for polinization? Fertrilize?

Answer from Pat:
You bring up a most interesting question. When I hear of “mystery” avocado trees that have never flowered or fruited, I usually think that the tree grew from a seed and the solution is to cut off the non-bearing top and graft a good variety onto the trunk, but your tree bore one fruit this year and is now loaded with flowers. So far so good. The problem is most likely, just as you are thinking, the lack of a pollinator. However we cannot know what variety you have unless you can get this information from the former owner of your home.

As I already stated on this website—(Please see:https://patwelsh.com/wpmu/blog/trees/pollination-of-avocado-trees/) there are two kinds of flowers on avocados “Type A” and “Type B”, and in order to have fruit you need to provide a pollinator tree or graft three branches onto your tree with the other kind of blossom from what it has in order to provide cross pollination. Without knowing what variety you have perhaps you should contact the Rare Fruit Growers (clubadmin@crfg.org) in your region and see if you can have some branches of both Type A and Type B avocados grafted onto your tree. That way you would be sure one of the branches would give you the right kind of flower for pollination. Another idea is to purchase a second tree and look for one which is grafted with two varieties, one with Type A blossom and the other with Type B blossom. Or, alternatively, plant two young trees in one hole, which is often done to save space. They will grow up together and if the trunks are touching, become one tree with a natural graft joining them. Since you have no time for this to work this year you need to get a couple of branches covered with flowers and hang them in your tree while there are flowers so the bees can mix the pollen or maybe you could hand-pollinate.

On the other hand you do mention you got one large fruit and it ripened within a week and was the best avocado you ever ate. Perhaps your tree is a ‘Pinkerton’, which bears through winter, has medium to large fruit of excellent flavor. ‘Pinkerton’ has a Type A flower so you need a Type B pollinator. ‘Bacon’ is another large-fruited type that bears in through winter and the fruit is very round compared to other fruits. The fruit has a nutty flavor, different from other avocados. It’s one of my favorites. It also has a Type A flower. ‘Holiday’ also is still bearing in winter and has large green-skinned fruit on a weeping tree with Type A flower.(‘Pinkerton’ has the regular avocado fruit shape and the skin is lighter green. ‘Bacon’ has slightly darker green skin than ‘Pinkerton’.) The interesting thing is that all these large-fruited types have Type A blossoms, so you could just take a chance and plant a tree such as ‘Sharwil’ that has the Type B blossom, but that does sound risky since we can’t be sure your blossoms are Type A. I think you had better provide both, just in case.

I hope this helps! By the way, one other thought occurred to me, but it is not likely to be true: Did your tree have blossoms last year? If it never bloomed before (except for one flower) and had one excellent fruit this year and now has abundant flowers for the first time, that might mean you have a miracle tree that is from a chance seedling. (Seedlings may never bear or may not bear for many years.) If you have a seedling tree with excellent fruit you may have discovered a brand new and useful variety. The chances of this being the case are slight however.