To Jess,
I have a Hass avocado tree that is approximately three metres tall and eight years old that has flowered for at least the last four years.
The fruit sets normally every year and develops to about the size of a small pea and then all the fruit fall off.
The tree is well protected in an orchard away from any wind and gets regular water and fertilizer.
I cannot work out why this happens, I even contacted Sabrina Hahn but she declined to answer.
I have heard about A and B hass avocado plants to promote fertilizing but this cannot be true if the tree produces fruit, especially since neighbours have avocado trees as well.
I would appreciate your response, thanks.
Barry Granger.
Falcon
Firstly, it’s worth noting that some degree of fruit drop, known formally as ‘abscission’, is normal for avocados.
Of the hundreds of fruits that set, only a small percentage usually survive to maturity, as the plant invests its energy into the most successful fruits and gives up on the others along the way.
However, after doing some research I’ve got a few suggestions to make to ensure you don't lose all your fruit, which is of course pretty disappointing after such a promising start.
Avocados have a very shallow root system, and as such are sensitive to top soil disturbances.
Most seasoned avocado growers suggest leaving any fallen leaves in place where they fall, and to avoid disturbing the soil around the roots.
Any changes to watering routine can also stress the plant out and cause its fruit to drop, especially sudden dry days, which is a common problem in Western Australia, even for diligent gardeners.
It’s also possible that nutrition is a problem: you should only fertilize the tree outside the fruiting/flowering period, and it’s possible that sometimes the food you’re giving it isn’t quite complete.
Often fertilizers have a good mix of nitrogen and potassium, but you may need to top-up the potash yourself, as this is the ideal trace element to add to help with fruit retention on any plant.
Try adding a little extra around the roots of the tree: it should help.
Do you have a gardening question for Jess? Send your queries to jess.cockerill@fairfaxmedia.com.au