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| Preparing Perennials for Winter - Tuesday, October 17, 2006 at 11:06 |
| Suggestions for handling Established Perennials that we grow: how to treat them for winter. 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 fall or spring Brunnera--pull off dried foliage after frost kills it (prevents any leaf disease from overwintering on plants) Butteryfly Bush (a woody ornamental that is treated as a perennial here) cut back in spring only please. Caryopteris (a woody ornamental that is treated as a perennial here) trim back in spring only please. 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 (prevents any leaf disease from overwintering on 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 (prevents any leaf disease from overwintering on plants) Fern--leave up for fall, cut back in spring Geranium--cut back in fall or spring Goldenrod--leave up for fall in 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 (prevents any leaf disease from overwintering on plants) Rudbeckia--cut back in fall or spring (the seed heads are great little bird feeders, but if they had diseased foliage, its best to cut off in fall and remove in fall) Russian Sage--cut back in spring Salvia--cut back fall or spring Sedum--cut back in fall or spring (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 as well. 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 newly planted in the fall perennials) really need to be mulched very well when planted around the plants, 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. A necessary step to ensure good rooting in fall and to help them overwinter the best. That is the reason we need you to stop doing installations of perennials by the end of October -- so they have a chance to root in before the ground freezes. Thank you, Tim Flood |