I wish I'd read this last week before I trimmed my Russian sage plants to three inches from the ground! Will they make it through the winter?
In My Garden Blog:
Northern & Central Midwest
October 22, 2009
By
Kate Jerome,
Pleasant Prairie, WI
Don't cut these lovely miscanthus back until spring.
Fall Perennial Care
By the time you are reading this you may very well have had your first frost. Even if it's still to come, though, the garden is beginning to wane, and perennial flowers are not looking so good. Except for mums and asters, of course. So, I thought I'd give some tips on exactly what to do for winter as those perennials begin to die back.
First, let me say that in most cases, the plants really don't care whether you cut them back now or wait until spring. The only exceptions are those that had disease issues and should be cut back and disposed of, and a handful of particular plants that actually do poorly if cut back in fall.
Black-eyed Susan
Although I usually recommend that these seed heads be left intact through the winter, if your plants had the lovely black spots of septoria blight this year as mine did, it's a good idea to cut them back now and get rid of all the foliage. If they were healthy, then by all means, leave on the seed heads to feed winter birds and offer some accent in the winter garden.
Purple Coneflower
These seed heads look lovely on the plant through the winter. If you have the inclination and time, you can run your hands along the stems to remove the leaves and not have the black crispy leaves hanging on all winter.
Lavender
These wonderfully scented plants should be left intact through the winter. They won't thrive next year if cut back now. Simply leave them as they are, and then next spring as soon as the new growth begins, cut back the old growth by about two-thirds. Lavender has its hardest problem surviving winter if it is in a spot that stays wet. Russian sage also needs to be left intact until you can cut it back completely in spring.
Phlox
Garden phlox often has issues with mildew in the summer months, so it definitely benefits from being cut back now. Try to remove all of the leaves and stems to prevent the mildew spores from overwintering in the garden. It's best to send the debris off to the city compost facility.
Monarda
Although there are many mildew-resistant varieties of bee balm out there, treat the same as phlox if you had mildew. If not, you can leave the stems up since the seeds will feed birds and wildlife.
Lily
Lily stalks serve no purpose staying on for the winter, and actually look pretty ragged. Simply nip them back at ground level. Try not to pull the stalks as you might injure the bulbs.
Iris
Iris foliage will often remain green through the winter under snow, but unfortunately, it often harbors iris borer eggs. The best advice is to clip it short now, and then in November after it has died back, remove any traces of foliage to dispose of the eggs.
Join the discussion!
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Susan | October 22, 2009 | 5:38PM
Kate | October 22, 2009 | 9:02PM
Susan - if they are in a well-drained site, they may come through just fine. All you can do is keep your fingers crossed!
Lita | October 23, 2009 | 8:50AM
Thanks for the terrific information. I made a copy to add to my fall gardening notes.
Kate | October 23, 2009 | 10:18AM
My pleasure, Lita!
Nancy A. | October 23, 2009 | 12:54PM
I have a Crepe Mrytle planted too close to the front of my home. It has grown too tall and too wide. How can I cut it back and still save it? (PS I didn't plant it, it came with the house 12 years ago). Thanks for all your tips!
Barb of Mpls | October 26, 2009 | 9:43AM
Thanks for the tip about wintering Russian Sage. I was wondering what to do with mine! Now I have the answer - in the spring. Question for spring: I only planted one Russian Sage plant because I did not know if I would really like it, nor if it would grow well in that area of my garden. Well guess what? Yes to both worries. So my question is this: how many plants would be best for this type of plant? I read that it needs about 36 inches to spread, which this one has. Would two more or just one more make it more appealing? I have room for 3 plants in that sunny to partial shade area. Thank you. bls
Nancy | October 27, 2009 | 8:26AM
You mentioned cutting back lily stalks. What should I do with the leaves?
Kate | October 31, 2009 | 12:23PM
Nancy - unfortunately we can't grow crepe myrtle here in my part of the country so I don't have any expertise on pruning them. I would suggest that you contact your county extension office for advice, or even visit a local nursery that offers the plants. They may be able to help you. I don't want to steer you wrong!
Kate | October 31, 2009 | 12:24PM
Barb - congrats to you for becoming a Russian sage fan! Plants generally look best when planted in odd numbers, so I'd opt for three in your case. They may grow together somewhat, but that's not a bad thing. A mass of three will definitely give you a nice focal point.
Kate | October 31, 2009 | 12:27PM
Nancy - when I mentioned lilies, I was talking about true lilies that have the leaves all along the stalk. Cutting the stalk takes the leaves also. I think you may be asking about daylilies which are not true lilies. For these plants, you can simply cut off all the foliage and stalks in spring or fall, whichever suits your schedule. I like to cut mine back in August when they start looking ragged and then I get a flush of new growth for the fall. Then, after frost, I simply mow them down with the mower or string trimmer and leave the foliage where it falls as a mulch. Good luck!