Have you noticed your fruit trees bearing more one year and less the next?
The curse of the fruit tree is that they can fall into a pattern of alternate bearing or biennial bearing.
While it is not a worrisome problem unless you’re an orchard farmer, it can be frustrating when you have heaps of apples for your strudel one year and can’t even make one apple pie the next.
So, what is biennial bearing, and can you prevent it from happening next harvest?
What is biennial bearing?
Biennial bearing, or alternate bearing, is when a plant or tree bears heavily in one year and very lightly or not at all in the next. This tendency means that fruit production is severely reduced in alternate years, and abundance can be few and far between.
During an alternate year, when your tree produces little to no fruit, it will instead focus its energy directly into flower production. This means that the next crop is most likely to be extremely abundant.
Thus, a heavy crop reduces blossoms that year, producing less fruit, and the cycle continues.
Causes of alternate bearing
There is no one cause of alternate bearing, instead, it is down to a multitude of problems, that mainly stem from neglect. The following lack of maintenance can lead to a biennial bearing for your trees:
- Receiving insufficient moisture or watering
- Overwhelmed by weeds
- Unfertilised or not having enough nutrients
- Late frost during the springtime
Common trees that suffer from biennial bearing
While any plant can suffer from alternate bearing, it is most common among fruit-bearing trees, including:
Prevention of alternate bearing
Prevention is the only way to get rid of alternate bearing in your fruit trees, and even then, using these techniques will not guarantee the ‘biennial curse’ will not continue!
Pruning
After a light or bad crop, pruning back your tree will mean less flowering and, therefore, a less abundant crop the next year. While this may result in two years of fruit scarcity, it will help break the alternation cycle.
Jon Lamb from the Good Gardening podcast recommends pruning back your fruit trees in winter.
Thinning
Thinning out the fruit from your tree in the weeks after initial flowering should also help break the biennial cycle. As Jon Lamb explains, “During a heavy crop year, reduce the number of fruits and fruit bunches 6 to 8 weeks after flowering.”
This will promote flower formation over heavy fruit production, meaning that your tree will be perfectly abundant by the time next year comes around! You can thin out your fruit tree manually or through chemical agents, which is how large orchards and fruit farms usually operate.
Crop nutrition
Finally, having good crop nutrition and properly maintaining your fruit trees will mean that an alternate bearing cycle may never eventuate in the first place.
If you have a particularly heavy crop year, Jon Lab recommends a full application of fertiliser immediately after harvest. He says, “Make sure this is watered well into the topsoil beneath the trees and keep them well watered through autumn.”
Related stories
Native ad body.
Native ad body.
Native ad body.
