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Suggestions for handling established Perennials
How to winterize them for Wisconsin winters
By Tim Flood
Anemone- cut back fall or spring
Aster leave up for fall, cut back in spring
Astilbe leave up for fall if you like to see the dried flower heads, or cut back
in fall or spring
Brunnera pull off dried foliage after frost kills it (this prevents any leaf disease
from over-wintering on the plants)
Butteryfly Bush cut back in spring only, please
(a woody ornamental that is treated as a perennial here)
Caryopteris trim back in spring only, please
(a woody ornamental that is treated as a perennial here)
Catmint- leave up for fall, cut back in spring
Columbine pull off dried foliage after frost kills it in either fall or early spring
Coneflower best cut off in fall and remove all old foliage (this prevents any leaf
disease from over-wintering on the plants)
Coreopsis leave up for fall (important) and cut back in spring (they hate to
be cut in fall)
Daylily cut back and pull off all foliage in fall (this prevents any leaf disease
from over-wintering on the plants)
Fern leave up for fall, cut back in spring
Geranium cut back in fall or spring
Goldenrod leave up for fall if wanted, cut back either fall or spring
Grasses PLEASE leave all up for fall and don't cut back until spring
Heuchera (Coral Bells) best left alone until spring, then in spring pull off only dried
leaves, don't cut way back
Hosta pull off old foliage after frost kills the leaves
Iris cut back in fall or spring
Ladysmantle cut back fall or spring
Lungwort cut back fall or very early spring
Peony cut back in fall
Phlox cut back in fall and remove all old foliage (this prevents any leaf
disease from over-wintering on the plants)
Rudbeckia cut back in fall or spring (the seed heads are great little bird feeders)
But, if they had diseased foliage, it’s best to cut off and remove in fall
Russian Sage cut back in spring
Salvia cut back fall or spring
Sedum cut back in fall or spring (they look great in winter if you leave the
taller varieties up)
Veronica cut back in fall or spring
Woadwaxen cut back in spring like you would a Spiraea
I hope that answers any questions you might have. Some people like to go out and just cut
everything to the ground. When you do that, you have nothing to look at all winter long (and
winter can be long in our area). Why not leave some of these plants alone and enjoy their
dormant, spent flower heads or foliage as they sculpt the snow and add tons of winter interest
to the landscape?
As with all perennials, it is always best to clean up any foliage that was diseased this past
growing season as that will help eliminate re-infection next spring. Perennials love a fresh
application of mulch in fall, as do most deciduous shrubs. If you are growing tender
perennials in your yard, be sure and give those plants a few evergreen boughs or a covering
of marsh hay after the ground has started to freeze to keep the ground frozen on those items
all winter long. Freezing and thawing of perennials can cause them to start growing before
they really should, and then when they freeze again, it can cause damage. The evergreen
boughs or hay will prevent the freezing or thawing, and will prevent and damage. Newly
planted perennials (especially those newly planted in the fall) really need to be mulched very
well around the plants right after planting and then also mulched with evergreen boughs or
marsh hay to prevent these plants from being heaved out of the ground by that freezing and
thawing process. This is a necessary step to ensure good rooting in fall and to help them
over-winter the best.
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