Preventing fruit fall in Finger limes and other Citrus.
Although we may think that fruit trees produce fruit for our benefit, the reality is that the reason for fruit production is to protect and nourish the seeds within.
Production of seed ensures genetic variation and the survival of the species.
For plants, survival of the species regulates so much of a plants reaction to environmental situations.
Most fruit trees including citrus, as a survival mechanism, will often set far more fruit then the tree can possibly bring to maturity. This is to allow for adverse weather condition, marauding animals and any other situation that may reduce the final crop. If these disasters don’t occur, there will always be a certain amount of fruit fall.
If pollination has been very successful, it can be as much as 60-70% of baby fruits.
Fruit fall mostly occurs when the fruit are extremely small, often only several weeks after the flowers have finished.
There can be another shedding of excess fruit when they are about ¼ of their eventual size but from then on in the tree should be able to bring the rest of the crop to maturity.
If fruit fall continues it may be an indication of plant stress, so it is important that your plants have enough moisture, sunlight and essential nutrients to enable the tree to support the entire crop.
Excessive heat and strong winds are booth extreme weather conditions that can also cause fruit fall. It can be difficult to protect large in ground trees, which is one of the reason I grow a number of citrus, including the finger lime, in pots (on casters).This allows me to move them into a more sheltered position in times of adverse weather.
My finger lime has about 40 fruit on it, which is a lot for a 1.5 m tree in a square pot. There was great germination and fruit set this year. This resulted in some fruit fall when the fruit was tiny, but they are big enough now that if I maintain the tress well they should all reach maturity.
So to ensure that I don’t lose any more fruit I am trying the following:
• Avoiding fertilising with products with a high nitrogen ratio, as this may cause the tree to drop fruit in favour of putting energy into new grow.
• Instead I am applying a thick layer of comfrey mulch, which is full of potassium and phosphorous, both of which are nutrients needed for good plant health and flower and fruit production. By using it as a mulch it is gradually breaking down during the season and supplying the plant with the nutrients it needs to retain and nourish the fruit to maturity.
• If you do not have any comfrey on hand then apply a diluted application of seasol or a liquid fertiliser labelled Flower and Fruit, both will give similar results to the comfrey mulch.
• I am applying a wetting agent every few weeks to ensure what water is applied is retained and available for the plant.
• I will then top the pots with a thick layer of sugar cane mulch.
• An irrigation set up on a timer would be ideal to make sure the pots remain moist, however not possible. Instead I am filling couple of plastic drink containers with water, putting holes in the lids and the base, turning them upside down and pushing them into the mulch. This allows water to gradually soak into the potting mix keeping it always moist. I will refill and replace each, twice a week, when giving the pot a good watering.
I am confident that these strategies will work and come late summer/ early Autumn I will be enjoying delicious finger lime pulp in my drinks and with my seafood.
If you are worried about fruit fall in any of your fruit trees why not try some or all of these strategies.
For more information on starting your productive backyard, check out the website.
If you have questions about your finger lime tree, you can always ask me questions via my Facebook Page, Pinterest or Instagram!
Looking forward to a great harvest!
Happy Gardening Kathy