Sunday, March 29, 2020

Winter's Over? ... or Wintered Over?

In late March in Wisconsin, gardeners would love to say “Winter’s over.” But it is fairly commonplace in this state to receive a substantial early spring snowfall in late March or early April.  (One storm on April 11, 1973, was especially crippling to the Southeastern Wisconsin area… since we’re already coping with the COVID-19 crisis, let’s hope we won’t have to deal with excessive snow in the weeks ahead!)

While we cannot safely state “winter’s over,” we can enjoy plants that were wintered over!  In September/October in Wisconsin, gardeners often remove and destroy countless plants that are still lush and lovely.  We know a killing frost is coming soon, so we cut back perennials and dig out annuals and discard them into our compost piles.  While this is an appropriate action for annuals that look tired and withered, there is an alternative for annuals that are truly thriving late in the growing season

Healthy annuals often can be wintered over!  Just a few necessities…

1)     adequate light (artificial fluorescent bulb fixture with a timer set to 10 hours minimum OR a few south or west-facing windows)

2)     infrequent watering (just twice per month, thoroughly water each potted plant)

3)     clean plastic or clay pots with saucers or trays to prevent water spills

4)     fresh potting soil (commercial soil with time-release fertilizer is acceptable)

5)     insecticidal soap spray (in case a few hitchhikers travel indoors on plants)

6)     timing: most plants can winter over indoors from early OCTOBER through MAY (when moving outside, slowly acclimate plants to a part-sun environment)

Pictured are a few examples of plants I like to “winter over” at our house.
The succulent is in genus Echeveria. I originally purchased two single rosettes of this plant a few years ago; it has multiplied many times over, which allowed me to share with friends.  (It requires well drained soil and a pot with drain hole.)

This annual ivy is commonly called German ivy.  The genus Senecio thrives in sun or part sun, indoors or out.  This ivy makes a lovely addition to container plants and exhibits an ideal trailing habit.  
(This ivy should be sprayed with insecticidal soap before bringing indoors 
to discourage hitchhikers.)

Geraniums (genus Pelargonium) are easy to winter over; they need bright light and well drained soil. If light is adequate, the stems will NOT become leggy or spindly.  I can use these mature plants in containers during late April when I begin assembling new spring containers for outdoors.

Wintered over plants are just another form of recycling—try it!

M. Lynn Schmid,  Certified Master Gardener
A.A.S. Landscape/Horticulture/Arboriculture