As part of our continuing series about fruit thinning (a very relevant topic in spring) this week we’ll talk about the second main reason we do thinning, which is to protect the structure of our trees.
Most fruit is carried on the small side shoots, or laterals, that grow from the main branches — they are a very precious part of the tree, and need to be protected. Left to its own devices, the tree will frequently set so much fruit on a branch or lateral that the weight of the fruit breaks the branch, as you can see in the photos above and below.
Our job when thinning is to remove some of the fruit that the tree has set, leaving only as much as any structural part of the tree can easily carry.
It’s important to imagine how large and heavy the fruit will be when it’s fully mature – as a very rough rule of thumb, a short lateral can only bear the weight of one piece of fruit, and a longer or stronger lateral can carry two or more pieces.
Of course the actual amount of fruit you can leave on the tree depends on many variables:
the type of fruit,
the variety (cultivar),
the ultimate size of the fruit at harvest,
whether the tree is heavy, medium or light crop,
when it’s due to be harvested,
age of the tree, etc.
It’s fine to just follow the rule-of-thumb guidelines we provide, or if you’re keen to protect your tree and in a hurry to get good results you can use the charts we’ve developed in the Grow Great Fruit program and the Fruit Tree Thinning short course to save yourself a few years of trial and error!
There’s no thinning to do here – there’s only one apricot in this site, and it has plenty of room to grow during the season.
But while you’re checking all your fruit, you may notice instances like this where diseased flowers or shoots are touching the fruit.
It’s hard to see but the apricot is attached to the branch on the left hand side of the photo, and touching a diseased part of another branch on the right hand side that is covered with dead flowers infected with a fungal disease Blossom blight.
The disease that causes Blossom blight in flowers also causes Brown rot in fruit later in the season, so left alone, the fruit is very likely to develop Brown rot at the spot where the diseased flowers are touching.
So it’s super important to remove the diseased twigs either by pruning them out (it’s always a great idea to keep your secateurs in your pocket while you’re thinning) or just remove them with your fingers.
Depending on your climate most peach, nectarine and plum varieties will have finished flowering by mid-spring and you can see whether or not they’re going to have a good crop and get the thinning well underway.
Though thinning is a crucial job in the lifecycle of your fruit tree, it’s also a quiet and reflective time to spend a dedicated half hour or so with your tree and having a really good look at what’s going on. Enjoy!