Evergreens – Junipers

(Question)

I am trying to protect my junipers for the winter.  One juniper has browned the past two winters from wind burn in March/April.  For last winter I wrapped burlap around the green area but it went all brown anyway, but that area slowly came back.  This year I want to try spraying Wilt Pruf on the green areas but am confused about when to do so, what with our unseasonal weather (not complaining about that) and one of the instructions on the Wilt Pruf container which reads

“When spraying on …cypress, cedar, juniper…be aware that if species have not sufficiently hardened off for the winter whereby moisture retreats to the root system, moisture in plant cells could freeze if early severe freezing weather should occur.”

How does one tell if moisture has retreated to the juniper’s root system?  I’m in central Toronto and the juniper is in the front of the house roughly about seven metres from the house so gets wind from all directions.  There is a long open driveway beside the front lawn and so from there winds come from the west and northwest.

 

(Answer)

Thank you for enquiring regarding winterizing your Juniper trees with the anti-desiccant Wilt Pruf.

Evergreens continue to transpire or release moisture from their needles/leaves during the winter, even in their dormant state.   They are unable to replace this lost moisture as they can’t take up water through their root systems due to the water in the soil being frozen.   The needles may become brown and desiccated, particularly in harsh winter winds or on mild sunny days.

It is important to water the trees well until freezeup in order for each tree to begin the winter season well fortified with moisture.  We also recommend you mulch your junipers from about 6-8 cm away from the trunk out to the perimeter of the branches, with about 5 cm of compost, composted pine bark, cedar mulch or a similar organic product to help prevent a freeze/thaw cycle and to maintain moisture in the ground.

Watering your trees as early in the spring as possible is important as this will help them replace the moisture lost over the course of the winter.  Winter burn inevitably appears in March or April when there is a lack of soil moisture and the trees have been under stress.

Wilt Pruf is an organic product made from Pine sap and it is recommended that two applications be applied, first in November-December, and again in February, on dry foliage on a day with temperatures between 5 and 10 degrees C, with no threat of rain or frost in the forecast.  Spray both upper and lower surfaces of the foliage.  This is an optimum time to apply the product considering our mild and dry early December weather.

It is normal for a juniper to lose up to 30% of its needles during winter without any serious injury or harm to the tree.

The following link will provide good information should you wish to do further reading:

https://landscapedesignbylee.blogspot.ca/2010/12/winterizing-evergreens-anti-desiccant.html#.VmXGRmQrLxs