Thuja Green Giant and Leyland Cypress trees will tolerate partial shade. We want to discuss the upper canopy, the shade on one side, the impact of how being south versus north can affect a shaded planting site. We will also cover the symptoms of too much shade, pruning canopy shade trees, and also recommend a good substitute for privacy screens in shady locations.

A straight canopy of shade is not the best situation for Thuja Green Giant or Leyland Cypress trees. The least desirable situation is an evergreen or pine canopy, because trees under an evergreen canopy don’t even get sunlight during the winter. If that’s your application, don’t plant there! Sometimes it can’t be helped. For example, on Long Island and in the Hamptons area, some neighborhoods have rules about what can be cut and are very strict about cutting down native trees to replace them with something not native to the area. Even so, I do not recommend planting Leyland Cypress or Thuja Green Giant trees under a canopy. I have planted these varieties under a canopy that was very high and yet the shade affected the trees.

Northern locations tolerate shade better than southern locations if coming from deciduous trees! If the shade trees are deciduous trees, at least after those canopy trees lose their leaves, the green giant Thuja trees will receive full sun all winter. This is more beneficial from New York and north than in the southern states, because they shed about five weeks earlier in the fall than southern trees and don’t green up until a month later than southern deciduous trees. On Long Island, Thuja Green Giant or Leyland Cypress trees planted under a partial canopy of scrub oaks can receive full sun for seven winter months before leaves reappear, while similarly situated southern states can only provide five months of full sun. Shade on one side of your row is usually fine, because your Leyland cypress trees will still get powerful direct sunlight overhead. Thuja Green Giant or Leyland Cypress trees can grow three feet a year if properly fertilized, so remember that if one side of your row is shaded by slower-growing species, Thuja Green Giants or Leyland Cypress will outgrow larger trees. slow shading in most cases and thus eliminate the problem.

There are two main symptoms of too much shade;

The first is that the trees thin out. In the first planting, if the trees grown in the ball and burlap field, they will be thick at first. Over the years, shady apps will take their toll and shrink a bit. The second symptom of too much shade is slow growth rate.

Providing light by pruning offending shade trees is a great idea. If you cut off the branches of an evergreen tree that shades your row of Leyland Leyland cypress trees, those branches won’t grow back, so it should be a one-time effort. If your arborists prune deciduous trees like oaks, maples, they are more likely to need to prune again at a later date. If the branches of deciduous trees are cut back to the trunk, on the side that shades the Leyland cypresses, you can completely figure it out. The advice here is to do the overhead tree surgery before planting the privacy hedge below. The arborist will probably be able to let the branches fall if they do so before installing the Thuja Green Giant row, but if they wait until after planting, the arborist will likely have to tie off the branches to prevent damage to their privacy screen below. .

Good substitute varieties are Nellie Stevens Hollies for shade applications in Zone 6 and Canadian Hemlock if found in Zone 5. Also remember, when planting in a mature forest, nearby trees not only steal sunlight but will have established root systems that compete with your new plants for moisture.