PREPARING YOUR PERENNIAL GARDEN FOR WINTER
It`s that time of year again, Fall, a time to cut back and clean up the gardens before the snow
flies. We are in Zone 4, which means that plants that are hardy to zone 3(Duluth area) or 4
need minimal winter preparation. After the first HARD frost, cut perennials back to within 3
inches from the ground. Perennial plants die back to the ground each winter; their roots retain
the nutrients needed to shoot up new growth in the spring. Disposing of the leaves is highly
recommended as this will help cut down on future fungus and insect problems. This is
especially important for irises as the dreaded iris borer lays its eggs in the Iris leaves in the
fall where they over winter and hatch in the spring to feast and kill your Iris. Leaf removal is
also important for Peonies. The leaves from Peony bushes can hold a fungus that may cause
the plant to be unable to bloom the following year. For these reasons, we recommend
mulching (if needed or desired). Remember to keep watering your perennial garden until the
ground freezes. Lack of water can cause stress on the roots and make it difficult for the plants
to survive the Wisconsin winter.
Snow is the best natural insulator, so as you can imagine; perennial plants need the snow to
ensure their return next spring. Snow acts as an insulating blanket for your perennials, when
we have no snow, it is important to insulate your perennials in other ways. Many people ask
about tree leaves, because of the potential of spreading fungus or sheltering insects and eggs,
we recommend using marsh hay or straw for this type of winter mulching. Mulching is always
a good idea for your garden; it is especially needed for first year plants, late plantings and
plants that are tender for our climate.
Many gardeners experiment with growing zone 5 plants, such as Buddleia, Hibiscus, etc. Many
of these plants will do fine in Wisconsin if given extra protection. In these cases, it is best to
make a soil mound 8″-12″ over the plant and then add mulch over the soil. By doing this you
create an environment that keeps a constant temperature, thus insulating your plant until
spring.
Uncovering your perennials should be done once we are in the clear of hard frosts or snow. A
general rule of thumb is when the tulips start to bloom; it`s time to uncover.