Director of Horticulture, Eric Kimbrel
With the leaves now gone, we can make proper pruning cuts, eliminating bad branch structure in trees and shrubs. Dead branches in rhododendrons attract borers, so we remove those. Now is also when gardeners can prune plants that have gotten too big and reduce them by one to two thirds to their desired size.
As we’ve done in years past, we ordered bulk delivery of aged horse manure this winter to be applied as a top dressing to shrubs and new plantings such as spruce, hemlock, chinquapins, and azaleas. Not all plants at the Reserve get the premium horse manure treatment; wildflowers and perennials tend to get leggy and top heavy when fertilized, causing them to fall over. We use aged manure over fresh to ensure the plant isn’t burned or over fertilized (plus, it doesn’t smell!). A similar product that is more widely available at garden centers is Daddy Pete’s cow manure. If that is not available, you can use any brand of mushroom compost. Black Kow bagged manure can also be used; however, it is heavier to handle because it contains sand in the mix.
Another important thing to do as soon as winter arrives, or at the end of fall, is to apply an anti-dessicant or anti-transpirant to your broadleaf evergreens such as rhododendrons, hollies, and mountain laurels. Products such as Wilt-proof (which has a natural active ingredient) or Transfilm (a synthetic polymer) create a barrier on both sides of the leaves that hold moisture despite the wind and sun, for months at a time. You can also use those products on your Christmas tree, winter wreaths, and garlands to keep them looking fresh longer. At the Reserve we use the strongest application rate of anti-transpirant recommended to give us both the longest lasting protection and to avoid the need for secondary applications. The most devastating thing that can happen to some evergreens like rhododendrons in the winter is that the ground can freeze, preventing water from reaching the leaves when the air temperature is warmer. This causes the plant’s leaves and stems to eventually dry out and turn brown. This is known as winter damage, or burn, and it can sometimes kill a plant completely . Mulching or topdressing 3-4 inches will help keep roots more protected as well.
Winter is an ideal time to plan and or order what you want to plant in the spring. Currently we are cleaning seeds from their husks and have begun stratifying them in storage bags with moist sand or sphagnum moss in a refrigerator. This will last up to three months for many of the species. This process mimics winter conditions which will enable the seed to wake up, or break dormancy, and germinate when warmer temperatures are introduced. Some seeds have even germinated in the refrigerator after staying in there too long! Another stratifying technique is to sow seeds in pots and leave them outside for the winter but protected from animals. When spring temperatures rise, the seed will then germinate.
“Anyone who thinks gardening begins in the spring and ends in the fall is missing the best part of the whole year; for gardening begins in January with the dream.” Josephine Nuese