Caring for newly planted Leylands

[Dmandefy]

At the beginning of September I planted about 25 leyland trees, that came in as potted plants and had a height of about 2-2.5m with the intention of forming a hedge, so I planted them at about 70-80cm apart. After the first few days I started noticing some branches starting losing color, and turning towards the inside. Three weeks later the situation hasn’t improved but more branches seem to go down the same path. The most affected parts seem to be the new growth at the top of the branches and the actual top of the trees as well.
In the meantime I added some foliage fertilizer (generic NPK + micronutrients) a few days ago and a liquid soil activator that got applied at root level (mycorrhizal fungi).
My soil is not the best when it comes to drainage, it is a dense clay soil. That is why I tried to not overwater them, so I mostly fed them water once or twice a week at most.
Is there anything that I might do to not lose the trees. In the spring I had another attempt of planting 10 Californian Cypresses and they died out after about 2 months of planting. Would like to avoid having the leyland trees suffer from the same fate.

 

[Marck]

Hello, and welcome to the Forums.

Leyland Cypress (x Hesperotropsis leylandii*) does not do well in poorly draining soils, so the question now becomes how badly draining is your soil. Photos of the soil surface and subsurface may help, but judging from photographs is difficult. In poorly draining conditions any attempt at saving the trees will be an uphill battle. Also tell us more about the watering newly trees will need to be watered deeply, and kept moist, they just don't want to sit in saturated soil.

If drainage is the issue, one option is to replant the trees on mounds several feet high? This can improve drainage greatly even in heavy soils, but it requires extra space, labor, and often the importation of additional soil. Raised beds would give similar results, but remember these are trees and any such remediation would need to be on a commensurate scale.

* This is the currently accepted scientific name for the hybrid Leyland Cypress, but there are several other recent synonyms due to both parental species being placed in several different genera. One parent, Monterey Cypress (Hesperocyparis macrocarpa) was formerly Cupressus macrocarpa. The other parent, Nootka Cypress or Alaska Yellow Cypress (Callitropsis nootkatensis) has two recent synonyms Xanthocyparis nootkatensis and Chamaecyparis nootkaensis. Depending on the exact cultivar, either species may be the pollen or seed donor.