I have a young jackmontiei silver birch Half the leaves have been eaten by the sawfly caterpillars before I blasted them off with water. I want ensure that next year I stop them before they eat the leaves. What is the best time to spray the tree with specific incecticide ?
If you can obtain a product called Bayer Tree and Shrub Granules there, I would highly recommend giving the tree a treatment of the granules in early spring when the tree is first starting to leave out. The systemic insecticide in the granules should take care of the problem. You could follow that up with spraying the foliage down with some Bayer Advanced Complete Insecticide or insecticide of your choice about four weeks later.
My river birch has many suckers all around the base. I have cut them off but they grow right back. Do I just leave them or keep cutting them off? And the leaves are a pale green to yellow. Is that normal? Thank you.
Keep removing them! I have to get a few off mine too!
Iron deficiency may occur, especially in alkaline soils. This is evident by yellowing of the leaves. This problem is called Chlorosis and can be treated by introducing iron tablets into the soil.
https://www.gardeningknowhow.com/ornamental/trees/birch/planting-river-birch-trees.htm
What does cankers on silver Birch trees look like and can spores affect Rose bushes nearby?
http://extension.colostate.edu/topic-areas/yard-garden/cytospora-canker-2-937/
http://www.mortonarb.org/trees-plants/tree-and-plant-advice/help-diseases/canker-diseases
https://extension.psu.edu/pests/plant-diseases/all-fact-sheets/cankers
I am not sure what is happening to the birch trunks in the pictures, but here is some information on canker diseases in birch and other trees. A university extension agent or arborist may also be able to help you diagnose your tree's problem.
Can you move a 2 year old Silver Birch Tree?
You can. You will want to try and get as much of the root zone as possible, and make sure to do this during dormancy. Here is an article to help with moving mature trees: https://www.gardeningknowhow.com/ornamental/trees/tgen/moving-mature-trees.htm
My weeping silver birch tree has lost all its leaves at the top ,can I do anything to help it.i must add that it is about 46 years old .
Your tree may be infested with the bronze birch borer or another birch borer insect. These are the most likely cause in North America. In Europe, several fungi can cause these symptoms. Here is more information:
http://www.extension.umn.edu/garden/insects/find/bronze-birch-borer/
http://ento.psu.edu/extension/factsheets/bronze-birch-borer
http://wildrosetree.ca/insects-diseases-other-problems/why-is-the-top-of-my-birch-tree-dead/
My tree grows so tall and very little leaves. If I cut the top of tree down, does it continue to grow and more leaves will come out? Thank you so much.
Removing the top of a tree, or "topping", is not recommended because it will harm the tree's health and appearance. Instead, it is much better to let the tree grow in its natural form.
The tree may have had few leaves this year, potentially because of difficult weather conditions, but it will probably grow more leaves next year. See this article for more information:
http://web.extension.illinois.edu/askextension/thisQuestion.cfm?ThreadID=11743&catID=34&AskSiteID=34
A birch & a Chinese Hackberry have been cut down, leaving a stumps which I would like to be ground down. What can I do to poison the roots before the grinding takes place?
The tree service that took out some trees for me told me to paint the surface of the stump with Round Up right out of the container. It needs to be the concentrate type that you add to water to spray weeds. Only in this case do not water it down, paint it on the surface of the stumps in the concentrated form. Be sure it is on there for two to three weeks prior to having them ground down for the most effective kill. It is best to do this application as soon as possible after the removal so it gets absorbed in best. If it has been a while, drill some 3/8" to 1/2" holes down into the surface of the stump so that the concentrate has a good avenue for absorption. This has worked for me on several removed trees now.