Wednesday, April 11, 2007

Dealing with cold injury in our gardens

As far as assessing the damage from what happened last week, only time will tell? I know that many of the perennials (daylilies, sedum, hostas, etc.) in my own yard had already begun to put out new growth. And yes, this growth was probably quite tender.

You may have tried to cover plants with sheets, overturned plastic pots, or a thick layer of pine straw. This works well by holding some of the heat that builds up in the soil, and also insulating against cold winds. Some damage may still occur, but less than you would have otherwise.

For those plants that were exposed, scout around over the next couple of weeks to look for damage. Freeze damage on woody plants is usually seen as leaf browning and then leaf drop, or a blackening of a portion of the stem. Perennials show leaves that are droopy and seem to be almost white. I believe most of our perennials that were damaged will resprout with new leaves.

Regardless of the symptoms of freeze damage, all pruning of affected parts of woody plants should be delayed until after the danger of frost is past. Not only is there increased risk of infection when pruning before then, but the old plant material provides protection to areas lower on the plant which may not have been affected. When pruning freeze damage from a plant, prune back to healthy tissue.

5 comments:

Anonymous said...

cfecxThank you Diane for this update on how to deal with our plants re: the recent freeze.I will subscribe to this info in e-mail format for future updates. Thanks again. Bruce Driscoll

Anonymous said...

Hi Diane. Regarding the cold damage on things like hostas, daylilies, etc (non-woody perennials), how would you handle that cold damage...which is quite substantial in my garden. We did do our best to cover, but our garden is so vast that covering all just wasn't possible. Would you cut away all the melted hosta leaves, etc, or just let the new growth grow in around it? Right now, all my favorites are pretty unsightly. Also, my herbacious peonies (which were covered in little buds) have all broken. I can't imagine a spring without these delightful beauties...but compared to our local orchards my injury is but small. Any feedback on dealing with our cold-melted hostas, etc, would be appreciated.
Many thanks, Tina Masciarelli
Haywood County Master Gardener Volunteer

Diane Turner said...

Tina, the key to dealing with these damaged plants is to prune them back, but I would wait to do this until after this weekend has passed. The damaged foliage will serve as extra protection until danger of frost is gone. When you do prune, cut your herbaceous perennials to one inch of the ground. Cover them with mulch, to add additional protection for this tender growth.

Anonymous said...

This blog is great! Just when I start to wonder something... like when to cut back my ugly hosta or daylily leaves, the answer appears. Thanks, Diane for providing such timely advice.

Paula Gatens, Haywood County Master Gardener Volunteer

Anonymous said...

Thank you Diane for that feedback on pruning away all that cold damage. I thought as much about waiting until the cold of this weekend had passed. As a side note, we found that the hostas, etc, that we covered with sheets actually had less damage than the ones covered with plastic pots or just mounded up mulch. Although, we didn't have enough mulch to mound to the height you instructed. Your advice is greatly appreciated! Tina Masciarelli, Haywood County Master Gardener Volunteer