Correcting biennial bearing with fertilizer at the end of summer/fall?

I had about a massive amount of plums on my Beauty tree last year and less than 10 plums this year. I know I should have thinned but is there a way to correct this afterwards at the end of summer with more fertilizer?

If energy stores are too used up to produce flowers the following spring, wouldn’t a healthy dose of fertilizer after fruiting help to correct that? Or does it not work that way? Out here, we don’t really get full dormancy until November which would give 2-3 months after fruiting to being able to uptake extra nutrients from additional fertilizer?


I’ll be interested to hear the replies from the more experienced crowd. Donny, imo, while I do think it’s possible that increased fertilization could improve blossom, I have to say, I sorta doubt it. There is however a ton to be said of this question. Blossom and the yearn for the plant to make attempts at reproduction are most commonly artificially (or naturally) inspired by poor or declining conditions. The plant feels it’s in jeopardy, so it takes the necessary action to reproduce to ensure it’s own survival (in a evolutionary “learned” type of behavior). In other words…like us, it’s programming is set for the desire to pass it’s genes along before it, itself may fail.

It’s lack of blossom is far more likely to be attributed to other factors like weather or just a down year. Since it’s not going to produce though (or produce little) and you feel there may be an issue with soil fertility, there should be no harm at this point in fertilizing.

I assume when you mentioned you should have thinned more, you meant last year…right? I have often wondered exactly as you probably are. There is in my mind a finite bank in which to draw stores from, and you are curious as to whether your lack of thinning may have exhausted them…is this right? Again, I doubt it. My experience with plants off all types and genres is that they will expend everything they have to procreate. I do think there is probably a narrow window where (it would be so difficult to know) fertilization may invoke increased flowering the following spring. For sure, a well fed plant can no doubt. set and carry more fruit.

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Fall fertilizer won’t increase bloom the following spring on things I grow. The flower buds form early in summer or even spring not in the fall. I can already see next yrs flower buds on apricot and pluot. Haven’t really looked a nectarines but they also are forming next yrs flower buds now. Excessive cropping steals the energy from flower bud formation. Avoiding that is the route to annual cropping, better quality fruit, and less risk of breaking branches.

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So if I start adding fertilizer to some trees that I should have thinned, that might help to create new flower buds for next year?

I don’t see anything more than moderate vigor helping flower bud set. Too much vigor could reduce bud set. Thinning is the cure, not more growth.

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Fruitnut is right. Its all about thinning… now I have to go out and make myself thin to 1 apple/cluster. ugh… so hard to do.

Literally whole Ph.D. theses have been written on this subject. From my reading the major control on flower formation for the next year is due to hormonal factors. Highest among those is the presence of seeds and their formation of gibberellins.

There is a nice review in this Ph.D. thesis (DE Davis, 2002, VTech) (e.g. Ch. 1, Literature Review):

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