Perennial Care After The First Freeze

 

 

Cleaning Up Your Perennials for Winter

 

Fall and late winter are both times when you may find yourself cleaning up perennial beds, but not every perennial needs—or benefits from—the same treatment. Some plants can be cleaned up after a hard freeze, while others are better left standing until late winter or early spring.

Many herbaceous perennials, such as Daylilies and Cannas, naturally die back after freezing weather. Their foliage may turn brown or black as the top growth dies, while the roots or underground structures remain alive and dormant until warmer weather returns.

You may also notice ornamental grasses changing from green to shades of tan or straw. That doesn’t mean they’re dead—the dormant foliage can actually provide great texture and winter interest in the landscape.

 
 

How to Clean Up Your Perennials

 

• Soft, herbaceous perennials: Once the foliage has been killed by freezing temperatures, dead growth can be removed if desired. You can also leave healthy, disease-free stems and seed heads through winter. They can provide winter interest and may offer food or shelter for birds and beneficial insects before you clean them up in late winter or early spring.

• Woody and semi-woody perennials: Don’t automatically cut every plant back to 6″–10″. Plants such as Lantana and Autumn Sage (Salvia greggii) are often better left largely intact through the coldest part of winter in East Texas and pruned as new growth approaches in late winter or early spring. How far you cut back depends on the particular plant.

• Liriope and Mondo Grass: These grass-like plants don’t necessarily need to be cut back every year, but trimming away old or damaged foliage can freshen their appearance. If you’re going to cut them back, do it before new spring growth begins. Cutting after new blades have emerged can leave the fresh foliage with ragged, brown tips.

For large areas of Liriope, a mower or string trimmer can sometimes make cleanup easier, but use it carefully and only before new growth emerges so you don’t damage the fresh foliage or plant crowns.

 
 

What About Ornamental Grasses?

 

Ornamental grasses are often one of the biggest cleanup jobs, but there’s no hurry to tackle them immediately after a freeze. Deciduous ornamental grasses can be left standing through much of the winter for texture, movement, and interest in the landscape.

Cut them back in late winter before new spring growth begins. The appropriate cutting height depends on the species, size of the plant, and location of the crown, so avoid automatically cutting every ornamental grass to the same height.

Evergreen and semi-evergreen ornamental grasses may only need selective removal of damaged or dead foliage rather than being completely cut back.

Need help tackling the job? Check out our How-To Guide for Trimming Ornamental Grasses.

 
 

Don’t Feel Like You Have to Clean Everything Up!

 

A perfectly bare perennial bed isn’t necessarily the goal. Leaving some healthy stems, seed heads, and ornamental grasses standing through winter can add interest to the landscape and provide habitat for wildlife and beneficial insects.

The key is knowing what you’re growing. Remove diseased or problematic plant material when appropriate, clean up plants that become messy or collapse, and leave beneficial winter growth standing when it makes sense.

Then, before fresh spring growth begins, finish your cleanup and get those beds ready for another growing season!