What is meant by not pruning or trimming a tree when sap is flowing?

Question

I dont understand this.

why does a tree sap flow ? when does it do it?

why will this or not damage it to prune it then?

also, what are borers?

Answer 1

Sap is a generic term for the feeding system of the tree. You want to wait until the tree is dormant (hence winter). The "sap", meaning the food for the tree will be in the roots to keep them strong through the cold. A borer is several kinds of insects that feed off trees. If you prune a tree in the growing season, it will in a sense bleed, and it will draw insects.

Answer 2

This usually means during the Spring or Summer.
Basically speaking the tree draws moisture to aid in photosynthesis when the tree is in leaf, this causes "sap flow".

So the best time to prune MOST trees is during the winter when they are dormant (asleep).

That said it wont necessarily harm the tree in any way to prune it when the sap is flowing. It is unsightly but there is little scientific evidence to prove that causing a tree to "bleed" actually does it much harm.

In fact some trees (some Prunus species) should not be pruned during the winter and should be pruned while in leaf while the sap is flowing.

I suggest borrowing a good book on pruning that shows the correct pruning cuts and says when to do them for your species of tree. The RHS book on Pruning and Training is very good as is The Pruning of Trees, Shrubs and Conifers by Brown and Kirkham. You should be able to borrow both from your local library (in the UK).

Borers could be people like me who use loads of text to answer your question. In reality they are wood boring insects.

Hope that helps a bit to answer your question.

Answer 3

Tree sap is the liquid inside the tree that provides water and nutrients up from the roots to the leaves, which in turn make food for the rest of the tree. The sap of a tree is like the blood in your body and it circulates in a similar way (except without the heart to pump it and much more slowly).

In fall decidious trees go dormant in preparation for winter. They do this to prevent frost and ice damage and to compensate for the lack of sunlight in winter. When a tree goes dormant the sap doesn't reach the outer limbs but stays deep in the trunk (Much like what happens to the human body during hypothermia. The blood reduces in the limbs and circulates more near the heart to protect it from the cold.). When spring comes the sap "rises" or flows much more quickly and outward to the outer limbs to feed the newly budding leaves.

When you prune a tree in "rising sap" it is more likely that the tree will sustain damage because it will "leak" water and precious nutrients. Prune too much of the tree or too big a branch and you'll kill it. It would be like slitting your wrists...All the blood would run out! That's why it's best to trim a tree in late fall or winter because they don't have any "bloodflow" in their outer limbs and aren't as likely to "bleed out".

Borers are bugs that "bore" into various trees...They can do a lot of damage. Look up borer on the net for pictures and more information on the insect.

Answer 4

Borers are sap sucking insects. You need to spray the tree to get rid of them. Malathion works well. You don't prune or trim a tree when the sap is flowing because this will let insects and disease get into it. The sap flows starting in spring, lasting until fall. The best time to trim or prune is in fall or winter. This is when the sap is down. Then in Spring you will have healthy new growth.

Answer 5

Borers are little bugs that bore their way into plants. To get rid of them you need to use a systemic killer. this is one that goes into the insides of your plant. Sap flowing is when the plant is making flowers and leaves or storing up goodness to sleep through the winter. Always prune when the instructions advise, which is usually emd of summer (flowering) or spring. Sometimes both.

Answer 6

ok its simple the sap in a tree is up in the summer and down in the winter dont trim in summer when sap is up it will cause the tree to bleed and in some cases it can kill one it will also let disease get into the tree .a bore is a worm that gets into a tree through a cut it will bore a hole into the tree and eat on the tree till it is dead thats where it gets the name bore there is a spray you can buy to kill bores if you dont wait till its too late

Answer 7

Please don't think I'm harsh, but you are headed for trouble if you proceed without more basic info than you will get here.Go to a nursery and ask him to demonstrate how to prune your cherry tree.The plantsman will be glad to show you and explain basic gardening ideas that will help way more than we will here. He will be glad because you will return to him for all your gardening needs.

Answer 8

TC hit that one on the head. He's correct.