Should I wrap my evergreens in burlap?

I planted some new evergreens this summer and a gardening friend told me that I should either wrap them in burlap or spray them with an anti-desiccant for the winter. I have seen other gardeners wrapping plants in burlap. Is this a good idea for new evergreens?

— Scott Canova, Glenview

The best way to ensure that your new plants get through the winter in good condition is to provide them with extra water during periods of warm and dry weather in late fall. An extended period of cold, sunny days in November and early December can dry out newly planted evergreens. Planting the evergreens on a site with conditions they prefer is also important. A vigorous, healthy evergreen is best equipped to avoid winter damage. Evergreens planted over the previous three years should also be watered when conditions are dry and warm at this time of year. They should not go into winter under stress from being too dry, as this will increase the chance of winter burn and possible loss of the plants. Evergreens can lose moisture from their leaves faster than the roots can replace it from frozen ground when there is low soil moisture, freezing temperatures, and blowing wind. Mulching can also help prevent winter damage.

Generally, it should not be necessary to use burlap to overwinter evergreens such as rhododendrons, boxwood, and yews. Catawba rhododendrons with large evergreen leaves are challenging to grow in this area and need to be planted in sites with winter shade and protection from wind to prevent winter burn of the foliage. There is one area at the Garden where there had been consistent winter burn on the south side of a boxwood planting adjacent to a walk. The horticulturist installed a burlap screen for a few winters to protect these plants from the sun in winter. Evergreens can also be damaged by salt spray in winter after roads are treated with de-icers — a burlap screen helps reduce this type of damage. The higher the speed limit, the farther the salt spray will drift. A better option is to choose plants that have tolerance to salt spray rather than an evergreen like an arborvitae that is very susceptible to damage from salt spray.

Anti-desiccant sprays work by adding a protective waxy coating to the leaves of evergreens like boxwood to slow down the loss of water through the leaves. They are best applied when temperatures are between 40 to 50 degrees Fahrenheit with no rainfall for three to four hours. Anti-desiccant treatments last for about three months. Applying an anti-desiccant spray may help your new evergreens, but it is a maintenance practice that I do not use. Focus on proper siting of evergreens, planting them properly, and providing supplemental water late in the fall season to be successful with evergreens. Any evergreens you have planted in containers for winter interest should be occasionally watered throughout the winter when conditions are dry and above freezing.

For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.