Question
I'm told it's best to transplant my 20' tall cypress trees during the winter months because they're dormant. This makes sense, but I'm confused about watering. If they're dormant, how do they process the water/fertilizer I'm supposed to give them after the replanting? Can the roots still absorb these offerings when they're dormant?

Answer
Evergreen trees and shrubs may be planted either in the spring or the fall. Evergreens should be moved earlier in the fall than deciduous plants so they have time to form new roots. They need at least 6 weeks before the ground freezes. In the spring, Evergreens can be planted up to 4 weeks after deciduous trees have opened their leaves, providing that the newly planted trees receive adequate water.

When you want to dig up a tree or shrub for transplanting, retain as much of the root system as possible. The exposed roots should be protected with moist burlap or newspaper or with polyethylene sheeting. Every effort should be made to reduce root exposure to wind and sun, keeping the ball as moist as possible. It's best to prepare the hole before digging up the tree you wish to move.

Size of the root ball and size of the hole:

For evergreen trees and shrubs the soil ball should be:

Width = 9-12 in. in diameter/every 1 in. of tree diameter
Depth = 6 in./every 1 in. of tree diameter

For example: A tree trunk 2 inches wide would need a soil ball of 18-24 inches wide and 12 inches deep.


The new hole should be twice the width of the root ball and the same depth. Fill the excess with good top soil and mulch and water. I prefer the spring planting but the fall may be ok if you and not in a snow belt.

It is true the dormant tree in the winter (usually after the hardwood trees have dropped their leaves) there is a marked reduction of water and food flow up form the roots to the leaves. In hardwood trees this flow is almost stopped. In conifers since they still have leaves the flow is drastically reduces. BUT the roots of both type trees are still growing and need moisture. Especially when you transplant and damage some small roots of the plant.

Cypress and most conifers do not need and should not be fertilized. Fertilizing newly planted trees can burn the roots that already under stress. I would not fertilize a transplant for at least a year and conifers rarely need additional fertilizer.