A little maintenance can go a long way.

As trees change colors in autumn, so do hostas, adding to your garden’s beautiful fall colors. And while these yellow leaves can be beautiful, you may be ready to trim them for aesthetic reasons. Additionally, cutting back hostas will help them grow stronger next year—and fall is the perfect time. Here, we chatted with an expert gardener about when to plum your hostas, as well as how to keep these plants happy and healthy.

Meet the Expert

Andrew Marshalla landscaping expert, wildlife garden designer, and the founder of Go Wild Landscapes.

Related: 20 Hosta Varieties With Beautiful Foliage and Blooms

Why Fall?

You never want to plum or cut hosta leaves when they’re green and thriving. This will damage the plant—when hostas are green, they’re still growing actively, even underground. Instead, you should wait until the end of fall—usually November in most regions—when repeated frosts have turned the foliage a muted color.

“Once the leaves are brown and no longer look good, they can be cut back,” says Andrew Marshall, a wildlife garden designer and the founder of Go Wild Landscapes. “The reason for doing this is partly aesthetics.” It’s also worth considering that diseases and fungi can infiltrate the plant via dried brown leaves, and a fungal attack can cause rot. This process will eventually kill the plant if left untreated, so it’s best avoided via pruning.

How to Safely Cut Back

With a pair of garden pruners, cut your hosta’s foliage back to around two centimeters above ground level. “This will remove the tattered brown leaves from your winter garden, and it will clear the border around the hostas, providing space for fall and spring flowering bulbs to show through,” says Marshall.

To make the cuts, grab several clusters of hosta leaves in one hand and plum the leaves with the other. Once the foliage is cut back, add a layer of compost mulch to the border. “This helps put nutrients back into the earth for next year,” says Marshall. “It will also protect the plant’s crown from winter frosts.”

Mistakes to Avoid

Not Pruning Soon Enough

The biggest mistake you can make is delaying (or avoiding) the pruning process. Many others fall perennials can usually be cut back in spring, but hostas are different. Brown decaying foliage makes the plant’s crown susceptible to garden pests and rodents. Voles, for example, may be tempted to call these browning leaves home during winter, and they’ll devour the plant’s roots and crown—weakening the plant, if not killing it entirely.

Not Deadheading

Another common mistake is choosing not to deadhead the plant’s spent flowers. Just as with other fall perennials, deadheading a hosta’s flowers redirects its energy back to caring for its bulb, which is especially important as the plant enters dormancy.

Overpruning

Finally, don’t overprune. Cutting back too much of the foliage can stress the plant, negatively impacting its overall health. Hostas also need those few centimeters of foliage to catch the sunlight and photosynthesis. “They’re a great foliage plant to grow in a shady spot in the garden,” says Marshall. “But they still need sunlight to live.”

Related: 12 Plants You Should Never Cut Back in Fall

Fall Care

Dividing

You can divide and transplant hostas in autumn to help spread them throughout an area. This gives the plants more room to grow when they reappear in the spring—and helps fill your garden with beautiful leaves. Split the plants in September if you live in a northern region and in October if you live in a southern region. Make sure to do this at least 30 days before the first frost; otherwise, the plants will have to be potted and overwintered indoors until spring.

Protection from Pests

Another thing to keep top of mind is pests. Hostas are, of course, particularly prone to attacks from slugs and snails. Marshall suggests going the extra mile to keep them at bay. “Use rings of copper wire for added protection around the plant’s base,” he says. “Adding a circle of sharp grit and broken eggshells can help protect hostas in an eco-friendly way.”

Watering

Finally, while hostas don’t require that much water once they’re pruned, watering is still the best way to protect the root system from freezing and thawing cycles. How and when to water, Marshall says, depends on where you live—hostas in areas with mild or wet winters are less likely to need much watering. When in doubt, always check with the experts at your local plant nursery or garden store!