15 Perennials You Should Cut Back in Fall for Healthier Blooms Next Year

When fall arrives, the flowering season of most perennials also comes to a close. But do you want to enjoy their blossoms (and, why not, foliage) next year as well? If you do, you may have to cut them back, so they can survive winter safely underground and return strong, healthy and willing to bloom next year. However, not all of them need this “end of season trim”! For some varieties, it may be a big mistake. You will have to be cruel to be kind with them…

Do you want to know which perennial varieties you need to cut back in fall?  Let’s meet them then, but first…

Why Should You Cut Back Some Perennials in Fall?

Why do some perennials need cutting back at the end of the gardening season? The reason is simple; soft stems and dead leaves that remain on them will turn soft even mushy and withhold water. This can lead to rotting down at the base, and then in the roots as well!

Another reason to cut them back is that these vulnerable dead stems may catch diseases, like molds and fungi, bacteria and even attract pests – of course, you don’t want that to happen.

Yet another reason is that dead stems and leaves prevent ventilation over the winter months, and again, this can lead to poor health and diseases for your perennials.

Finally, you may want to cut some perennials back to keep your garden looking tidy over the winter months, and save time and work in spring.

And now you know the “why”, let’s see the “who”, “how” and “when”.

1: Daylilies (Hemerocallis spp.)

Daylilies are some of the most generous perennials ever, with massive floral displays and also very dense and fleshy foliage. And that’s the problem, all those soft leaves will easily become mushy, and form a wet and disease infested mound on top of their roots over winter. If you leave them there, they may actually die!

Don’t wait too long to cut back daylily leaves – act as soon as the leaves have yellowed. This amazing flowering perennial has gone into dormancy by then and it doesn’t need the foliage anymore. In fact, it may concentrate humidity even during fall, damaging the roots.

Cut them back to ground level and your daylilies will come back super strong next year.

2: Plantain Lily (Hosta spp.)

Plantain lilies (or Hosta) are really delicate plants – you know it quite well if you grow these leafy beauties. The foliage comes straight from the base, and, if it rots, it risks infecting the roots very quickly, with bacteria and fungi moving to ground level and underground simply through the petioles.

So, like with daylilies, cut plantain lilies back to ground level as soon as the leaves have yellowed. I suggest you mark where you have your Hosta plants; then mulch, and, as soon as winter is over, remove it, so these leafy perennials are free to grow back.

3: Herbaceous Peonies (Paeonia spp.)

You should cut back only herbaceous peony varieties in fall, not tree or intersectional ones. So, before you go ahead, make sure you know which type you have, or you’d be making a big mistake!

Herbaceous peonies:

• Wilt completely at the end of the season.
• The stems come straight from ground level.
• They do not have woody stems or branches.

When should you cut back herbaceous peonies then? Wait till the first heavy frost, when the leaves blacken. And then, prune all the stems to about 2 inches above ground (5.0 cm), and make sure you do not touch the purplish pink shoots at the very base – they are next year’s growth. Yes, they prepare in fall for spring’s sprint!

If you want to know more aboutfall care for peonies, check out our detailed article here.

4: Joe-Pye Weed (Eutrochium spp.)

Super tall, super fast-growing, Joe-Pye weed will grow back strong and healthy in spring if you cut it back in fall, with its straight stems and large, purplish pink flower clusters later on. But if you don’t you won’t encourage new growth when the new season starts.

On top of this, the long stems become floppy over winter, which doesn’t look good for your garden and, again, it means that they are soft and vulnerable to pests and diseases.

You should cut Joe-Pye weed back when the foliage browns, which usually happens after the first frost. But you shouldn’t prune it to ground level: leave about 6 inches (15 cm) of stem at the base.

5: Solomon’s Seal (Polygonatum spp.)

I love Solomon’s seal, do you? Its arching stems with very elegant foliage are stunning, as are the many white, bell shaped and nodding flowers that dangle from them, followed by little black berries too as fall arrives. But you do need to cut it back if you want to protect it over winter.

Don’t worry; it has very strong underground rhizomes that will store away energy while it is dormant, and new shoots will come in spring.

So, as soon as the leaves yellow, just cut it back to ground level and don’t think about it till it comes back.

6: Japanese Anemone (Anemone hupehensis)

Japanese anemone forms large bushy clumps of stems, foliage and then lovely white to pink flowers – and that’s the problem!  These mounds will become moist and prevent ventilation over winter. Yet another super fast-growing perennial, you will also encourage new growth when spring warms up the soil.

So, as soon as frost kills the foliage, you should cut Japanese anemone completely back to ground level. Don’t wait till the stems weaken – it may lead to rot and all its bad consequences.

7: Tickseed (Coreopsis spp.)

So, you and pollinators have enjoyed the massive display of colorful, daisy-like flowers that tickseed has put on in your garden in late summer and fall? When it’s all over, it is time to prepare this perennial to survive the cold and wet winter months.

If you cut tickseed back for two reasons: it will promote new growth in spring, and it will avoid winter diseases.

When the foliage browns after the first frost, cut back all the stems to about 2 inches (5.0 cm) above ground.

If you want to help it spread, just shake the stems before adding them to your compost heap and scatter the seeds. On the contrary, if you don’t want it to spread too much, you should deadhead the spent blooms before they dry up completely.

8: Catmint (Nepeta spp.)

Catmint fills with elegant, upright spikes of purple flowers that rise above a dense mound of lush, green foliage – and you know what I am going to say… This can spell disaster in winter, when the leaves and stems die. Yes, it becomes a breeding ground for pests and molds. And it will also make your garden look a mess!

So, wait till the first frost, and you will see that the foliage blackens – this is the time to act. Cut all the stems back to 3 to 4 inches above ground level (7.5 to 10 cm), and it will be safe. It is fast-growing, so, it will grow back very strong in spring.

9: Astilbe (Astilbe spp.)

Astilbe is yet another fast-growing perennial which needs a very heavy “trim” in fall. For sure, you will understand that all those pinnate, frond-like leaves and what remains of the massive and colorful plumes that rise above them are dangerous when winter comes. Not only will all the dead foliage and blossoms invite pests and cause diseases, it can literally stifle new growth when spring comes!

On top of that, you will keep your garden tidy if you cut astilbes completely back to ground level as soon as the first day (night) of frost arrives – don’t wait till the plant starts rotting, as, by now, it will have no more energy left anyway.

10: Shasta Daisy (Leucanthemum × superbum)

Growing to up to 3 feet tall (90 cm) and providing a massive display of large white flowers with golden centers, as well as lots of stems packed with foliage that grow next to each other, Shasta daisies work an awful lot during the season. But they also produce a lot of organic matter, and quite dense clumps too. You guessed – this makes them very vulnerable to diseases, especially mildew (but other molds too).

So, if you want your Shasta daisies to have a healthy start in spring (and your garden to look tidy during the winter months), you should cut all the stems back to about 2 inches above ground level (5.0 cm) as soon as the leaves start browning, which happens after the first day of frost.

11: Garden Phlox (Phlox paniculata)

A super-fragrant perennial, garden phlox grows long and upright leafed stems that display amazing round clusters of flowers in white, purple, pink, red and violet at different times of the year, depending on the variety. But they all form dense clumps, which are spectacular during the season, but they look pretty sad and ugly in winter. And, as usual, they become a breeding ground for diseases and pests.

Like many other herbaceous perennials, garden phlox will start dying back after the first day of frost (or usually the first night of serious frost, it can survive light ones). You will notice that its foliage starts browning – well, this is time to cut it all down completely to ground level…

12: CoralBells (Heuchera spp.)

I bet you guessed why you should cut down coral bells to protect them in winter. Its foliage is stunning, large, lobed and in so many amazing colors, from green to red and purple and even “black”, and it forms large and dense clumps as well. The bell-shaped flowers on the stems that rise above just add more organic matter for pests to feed on and diseases to set in when they die and become soft and wet…

So, in late fall, when the leaves die, remove them all, down to ground level. But be very careful to leave the crown intact.

However, there’s an exception: in USDA zones 7 to 9 and above, coral bells are evergreen. In this case, you could just remove the dead leaves and keep the healthy ones – but I’d advise it only if winters are dry in your area.

13: Toad Lily (Tricyrtis spp.)

Exotic looking, orchid-like and really easy to grow, toad lilies are a really striking presence in any garden, with those weird-looking spotted flowers! Add the lush foliage (which can be variegated, by the way) on the long stems, and they can make your borders and beds look like a rainforest. Fortunately, they are very cold hardy but – wet winters can rot them away and even kill them.

To save your toad lilies, wait till the foliage yellows and browns, which is after the first frost, and cut all the stems back to ground level – these perennials have rhizomes underground to survive winters.

14: Bleeding Heart (Dicentra spectabilis)

Yet another herbaceous perennial you will have to cut back in fall is bleeding heart. Its romantic flowers on arching stems and its finely cut foliage look wonderful during the gardening season, but not in winter, when they can be troublesome for the reasons you know quite well by now.

Bleeding heart will tell you when it is time to prune it – it dies back spontaneously after the first frost, when you can cut it back to ground level.

15: Lady’sMantle (Alchemilla mollis)

Delicate looking and lush, lady’s mantle is a wonderful herbaceous perennial to “freshen up” gardens and borders with its green foliage. But look at it. Doesn’t it look soft and vulnerable? If you leave it on in winter, guess what will happen to it? It will become mushy, with all the consequences you know quite well.

Don’t even wait till it dies back, keep an eye on lady’s mantle in late fall, and as soon as it starts weakening, cut it back to ground level – you will be doing it a big favor!

Be Cruel to Be Kind!

I know, cutting back perennials looks drastic, even heartless. But if you want these varieties to survive winter and come back strong next year, you will have to be cruel to be kind.