Picea abies 'Cupressina' - click to enlarge


Cold Hardiness :

Rosa varieties
Composted leaf mulch mounded over the crowns of all roses, followed with salt-marsh hay protected the roses with a 95% success rate.  Method replicated for winter of 2014/15.

Method replicated for winter 2015/2016 with similar success rate.

Anti-desiccants claim to slow transpiration, or water loss, through the use of a protective coating on the leaf tissue.  In the winter, this water loss occurs during long dry periods of cold and thaw and in drying winter winds.  For the winter of 2014/15, we will not be applying any anti-desiccant.  Instead, all plants went into the winter well-watered and newly planted material received an extra application of mulch to protect the root zone. We did not apply anti-desiccant prior to or during winter 2014/15. All plant material survived, except what was damage by snow load.

Method replicated for winter 2015/2016 with similar success rate.

Rose protection

2012 mounded compost approximately 8” over crown.  Experienced 5% loss and 10% severe dieback for spring 2013.  Winter 2013, mounded composted leaf mulch and covered with salt-marsh hay for insulation.

To benefit the general gardening public in southern NH and northern MA GHHF is trialing various trees and shrubs observing their overall performance throughout the four season of a given year. Some of these plants are new selections which are being trialed for their perfomance in our USDA determined Hardiness Zone 5 with many selections predominantly grown in warmer climates. We hope the following reports will assist the homeowner and landscape professional in making informed tree and shrub purchases.

Calycanthus 'Venus'

Calycanthus sinensis

Acer palmatum cultivars

And others.......

Please check back later to see a complete list of our trial plants and photos from our test plots.

Under consideration for 2017:

Amelanchier canadensis and others
Rhus aromatic and typhina
Cercis Canadensis
Rhodo vaseyii
Viburnum varieties
Prunus maritima
Nyssa sylvatica
Parrotia persica
Dwarf evergreens, needled and broadleaf
Disease resistant varieties


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