How’s your garden looking this fall? Chances are those perennials that delighted you with their glorious color and blooms months earlier are now looking a little ragged. You may be tempted to start hacking them back – but don’t do it just yet.

Echinacea

If you leave your coneflowers alone until spring, the birds can feast on the seeds through winter.

Photo Credit: Jennifer Manning

Bee Balm

Bee balm is best cut back in fall because of its tendency to mildew.

Photo Credit: Jennifer Manning

Day Lilies

Prune your daylilies in fall.

Photo Credit: Jennifer Manning

Butterfly Bush

Butterfly bushes are best pruned in early spring.

Photo Credit: Jennifer Manning

It’s a good idea to leave some perennials standing until spring. Some bloomers, like coneflowers (Echinacea) and black-eyed Susans (Rudbeckia), provide seeds for birds the winter through. Other perennials, like stonecrop (Sedum) and ornamental grasses, keep up an attractive show ’til spring, so why cut them down at all?

Of course there aren’t any hard-and-fast rules about what to cut back in fall, but here are a few guidelines to help you get started.

Some perennials, like bee balm (Monarda) and Phlox, may have already felt the sting of your pruners because they tend to get unsightly mildew in summer. There’s no problem cutting these guys back as soon as their looks start to go. Blanket flower (Gaillardia) is another good one to cut back in fall because it helps the plant become more vigorous and hardy.

When the green leaves of columbine (Aquilegia) start to die, it’s best to take off all the foliage, otherwise the plant starts to look rather unsightly. It’s a good idea to scatter the seeds from the dried flower pods in your garden or just harvest them for later. And if you’ve got daylilies (Hemerocallis), go ahead and give them a fall trim. If you don’t do it now, you’ll be wrestling with all the dead leaves mixed in with new growth come spring.

On the other end of the spectrum are those perennials that hold their own throughout winter. Some remain evergreen and give you something nice to look at throughout the cold season. Others just handle winter’s chill better with all their foliage intact.

Some varieties of false spirea (Astilbe) will give you green throughout winter, so don’t cut those beauties back until spring. Pinks (Dianthus) are another perennial that can wait for springtime cutting. In warmer climates, these plants will give you beautiful blooms in spring and fall, and they keep their looks throughout winter.

Springtime is the right time to cut back your butterflybush (Buddleja davidii), too. You can cut this shrubby perennial back when you start to see new growth at the base of the plant, which can happen as early as February in some parts of the country. Don’t be afraid to cut it back to about 12 inches above the ground because it’ll put out tremendous growth all spring and summer. Finally, coral bells (Heuchera) is best left to spring trimming. Just remove the dead leaves. It doesn’t need a severe cutback.

A good way to determine when to cut your plants back in spring is to monitor them closely for new growth. When you start to see new shoots, you know you can remove the old foliage so the plants can focus all their energy into what’s emerging.

That said, chances are that whenever you choose to cut your plants, it’ll all be okay. Sure, there are a few perennials that’ll weather winter better if they keep their foliage, but if you trim your black-eyed Susans in fall, the garden police won’t show up at your door. If you wait until spring to cut back your daylilies, it’ll just be a little more work for you later. No worries. As long as your plants are healthy and doing well, cutting back your perennials really boils down to what works best for your garden and your schedule – and doing it in both seasons just gives you more chances to get out and enjoy your garden.