|After the first frost, is it okay to clean out my perennial garden, by cutting back? /Or, is it best to just leave them and cut back in the spring Types of flowers such as phlox, coreopsis, daylillies.|
|Here's some pointers on overwintering from "Perennials for Dummies" by Marcia Tatroe and NGA.
1. Cut back on watering as temps. cool. This signals plants that it's time to go into dormancy and helps "harden" them off.
2. If you had any insect problems, remove any plant debris and mulch from that area so eggs and disease won't overwinter.
3. Place a fresh 4-6 inch layer of organic mulch around the base of the plants.
4. If your temps. are regularly below 0 degrees Farenheit, don't cut back the perennials until late winter or early spring. The dead foliage helps protect them from cold.
5. After the ground freezes, cover the whole bed with a loose layer of straw or hay. Leave it until early spring and then gradually remove it as temps. warm. Don't remove it all at once.