What is the best evergreen for barrels that is hearty through Kentucky winters?
The Gardener’s Answer
Container gardening is a nice option when space is limited or just to add interest to the garden. Whisky barrels have a long history here in Kentucky and repurposing them as a planter is commonplace these days. It’s nice that they expand and contract as much as the rings allow, but they are not susceptible to cracking during the winter months like clay and glazed ceramic pots. Additional drainage holes are easy to drill if needed, and the barrels are sizable enough for a decent size plant or a nice combination planting.
As far as growing evergreens in containers year-round, there is always a risk of damage because they are more exposed to the elements and not as insulated as those planted in the ground. I’ve successfully grown various evergreens in containers for several consecutive years. They eventually go in the ground because no plant wants to live its entire life in a container.
Broad-leaved evergreens like holly, southern magnolia, nandina, boxwood, and laurels can be damaged by excessive wind, especially if they go into winter without sufficient moisture. Needle-leaved evergreen choices such as pine, juniper, arborvitae and spruce are much better options. Whatever evergreen you choose, make sure it’s not too small for the barrel.
In general, plants should be about 2 inches smaller than the container they are growing in. Fill the barrel with quality potting soil and remember to water into the fall while the roots can still take it up before the soil freezes. A layer of mulch, no more than 2-3 inches thick, is beneficial in terms of moisture retention and soil temperature.
If possible, move your barrel up close to the house where it will benefit from the radiant heat; this will also help protect the plants from harsh winds. Southern exposure should be avoided. Morning sun and afternoon shade is ideal during the winter.
Avoid fertilizing during the winter months, but you may need to hand water if the barrel is under cover and Mother Nature cannot reach it when it snows or rains. Even though the evergreen will go dormant, the roots should never be allowed to completely dry out. Make sure the drainage holes are not clogged so excess moisture can drain. Otherwise, the water can freeze and damage the roots. Visit your local garden centers to see what catches your eye.