Fall Perennials – To Cut or Not ?

In the Fall deciding what perennials to cut or not, can be a little intimidating.  What if I chop them and they never return, what if I don’t and they die anyways !  Even while cruising through your garden, you’ll notice there are always some plants that still look gorgeous even when they’re not in bloom. It’s almost like that neighbor across the way, who is still stunning  even without makeup. Oops, that was the old neighborhood, (we’re now in a 55+ community), so that won’t happen again till we’re at the viewing , “Oh doesn’t she look good”… are you kidding me …. compared to what !!!

And one of the most common problems is deciding what perennials should be cut back in the fall.  So before you dart out with those scissors or pruners you’ll need to do your homework and find out what’s best for your plants in your location.

Because if, when and how you trim these puppies will affect their future performance, so here’s an overview to give you some insight and help keep them coming back and looking fabulous !.

Winter Interest & Food: 

If you’re interested in perennials that provide food for birds, and look great against a blanket of snow, consider leaving rudbeckia and purple coneflower standing.

rudbeckia goldstrum
Rudbeckia “Goldstrum” Photo Source: Heidi Horticulture

Also consider most late-flowering daisy-type perennials as well as these examples with nice seed-heads and sturdy stems : AchilleaAgastacheAsterAstilbeBaptisaBuddleiaCheloneCimicifuga,EryngiumEupatorium, taller Sedum, and ornamental grasses look beautiful fluttering in the winter wind.

However, since most perennials provide very little winter interest, and pretty much begin to look really frumpy all by themselves, there’s really no reason to leave them cluttering up the garden.

But you’ll need to make that call based on what your plants need and your zone.  Do your homework.

 

Perennials & Disease:  A word of caution for leaving fallen plant foliage on… this can promote and encourage disease, especially to those plants that have a natural tendency to have this problem. Since these damp, moist conditions are ideal for insects and disease, you don’t want to provide winter lodging for these little buggers, there really not good guests.

 

daylily stella d oro
My daylily “Stella d Oro” in late Sept. , starting to fade off.

Those perennials commonly associated with disease or insect problems should be cut back in the fall. Also be sure to not only remove but also destroy the leaf litter below them, where the insects and disease may be hiding , or you could be asking for trouble.

Some examples: Columbine, Crocosmia, Daylily, Delphinium,  Hollyhocks, Iris (Bearded types, remove only the dead leaves), true Lilies,  Monarda, Peonies, Summer Phlox, Tricyrtis, and Veronica (tall types).

 

 

 

 

Perennial “Rosette”: 

What Is a Rosette Plant? When looking through gardening catalogs or on the Internet, you may be confronted with the term “rosette.” Although it sounds like it ought to be the name of a plant, it actually is a description of how a plant grows. If a plant grows in a rosette form, the leaves will radiate from the center stalk either right at ground level or close to the ground. The term rosette is used because the pattern resembles the habit of a rose’s flower. Many types of plant grow in a rosette pattern.

liatris kobald
Liatris Kobald in full bloom    via  American Meadows

Most succulents that form rosettes maintain that form their entire  lives, example would be agaves or aloes. Examples of perennials that begin life as a rosette are geum, liatris. These perennials often emerge as rosettes and stay that way for the first year, then the following year they grow in a larger, more shrublike pattern. Most ferns begin life as rosettes, and many stay in that form. Others may grow a central stalk.

Although you can trim the upright stems back, these lower leaves need to be left alone in the fall. In spring a quick trim
with the scissors to remove only the brown or dead parts, will be enough to tidy them up.

Some examples: AchilleaAsterCoreopsisDigitalisErigeron Gaillardia Heuchera, Bearded Iris, Shasta Daisies, Penstemon, Tiarella, Verbascum, Poppies, Polemonium, Potentilla , Salvia, Scabiosa, Stachys, and many of the hardy ferns.

 

Lavender Hidcote
Lavender Hidcote via  Amearican Meadows

Evergreen perennials :   Usually the best time to trim these is immediately after blooming, if at all.

Anyways here are a few that you probably don’t want to cut back in the fall, just let them stand watch in the winter (actually, most of them will gradually get wimpy on their own and you can gussy them up in the spring):

ArabisArmeriaArtemisia , Aubrieta, Aurinia, Bergenia ,CerastiumCorydalisDianthus,  evergreen Euphorbia, Helianthemum, Helleborus,  Heuchera, IberisKniphofiaLamium, Lavender, Liriope, Phlox (creeping types), Primula, Pulmonaria, SaginaSaxifragaSedum (many creeping types), SempervivumTeucriumThymusViola.

 

 

Woody Stemmed Perennials : Some examples: Buddleia, Caryopteris, Erysimum, Fuchsia, Hypericum, Lavatera, Perovskia (Russian Sage), Phygelius, Santolina.

perovskia russian sage
Perovskia (Russian Sage)   “Little Spire” via American Meadows

Since these have the wood like stems, do not cut them back in the fall , if you do, it allows the  snow and rain to get into the stems and swell up, this can cause  them to freeze and die. They also provide some winter interest  so leave them be until spring. When  spring comes around you can prune them back,  leaving about 6 inches of woody stem for the new buds to appear from.

 

flame-50-pc-newFor most of this type of perennial,  the more you prune them back in spring  (leave at least 6 inches of the woody stem though)  the more compact and full they’ll be at their peak.  So if you like the wild & wooly look go easy on the spring pruning…..the more refined and fuller look, cut those puppies back. Again, do your homework.

 

A few more FYI tidbits:

A common cut back rule for most perennials, if they:

  • Bloom in early spring to early summer…cut back in the fall
  • Bloom mid- summer to fall…cut back in the spring.

This is only a reference point though, you still need to do your research, as you can see from the above info, it varies a lot.

Location

The location of your plants has an impact on how the winter harshness will affect them. If your garden is located near the house, abuts a fence or surrounded by trees this provides some shelter, and they will react differently than those in an open unprotected area.

Hardiness Zone

With all that said you should still check to see what is recommended for your specific plant, in your zone, and the location in your garden.  Even though it can be grown in zones 4 -8,  we know there’s a big difference between winters ….a bulky sweater or down coat… 50 degrees or 10 below!

So you see, you are the guardian of your garden and you owe it to them to provide the best protection and care and they’ll return that kindness many times over and make you proud.

Get to Worksocks-toes

Now pop that fall jacket on, pull up those comfy wool socks and ask your partner to have  a nice warm meal ready for you when you come in from working in the garden this evening (if no partner is available, borrow one or just call for take-out and home delivery).

 

 

At the End of the Day

But don’t stress out on whether you made the right decision , after all it’s not brain surgery, the worse that can happen is you’ll have to replace a plant or two….they’re only plants—and gardening is suppose to be fun so ….R. E. L .A. X …. you’ll do just fine.

 

When you’re all done with the slicing and dicing in the garden, make time to just sit back, relax and  have a cheer-10-27-16-bestsglass of your favorite beverage, with that warm meal, that was prepared especially for you (okay, so it’s take out, at least you didn’t have to cook) ………you deserve it… another job well done.

 

 

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