Hostas are generally easy-care plants that add texture and spark to shade gardens but a few extra steps in autumn can make the difference between winter survival and plant loss.
When nighttime temperatures start to dip toward freezing and trees lose their leaves, it’s time to prepare and protect your hostas from winter weather.
From the smallest dwarf varieties to those that grow to 4 feet tall, these well-loved foliage plants start to fade and die back.
How to Care for Hostas in the Fall
Hosts thrive in USDA hardiness zones 3 to 9. Leaves grow from a crown and die back over winter but the crown and root system are perennial, entering into a dormancy period when days grow shorter and temperatures drop below 40°F.
It’s important to note these plants require a cold period of at least 30 days, depending on variety, in order to generate new foliage in spring.
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Pruning
Most gardeners opt to remove dead leaves in autumn. Foliage turns yellow, then brow, and falls from the plant naturally after dying back completely. Fading leaves can often be pulled from the plant or, if you have large, full plants, you can cut foliage back in early winter. Remove any new leaves with a gardening shear. Take care to avoid damaging the plant’s crown.
You can cover the crown with spent leaves to feed plants overwinter but removing and disposing of them is the safest bet for protection from overwintering insects, pests, and disease.
Dividing
Hostas are most often divided in spring but they can be divided in autumn. In northern zones, split plants in September and in October in the south.
If this is done at least 30 days before the first frost in your area, divisions can be transplanted outdoors in a new location. If you’ve waited too late, divisions can be potted up and overwintered indoors then planted out after frost the following spring.
Mulching
In mid to late November cover the entire plant with a layer of pine needles or straw to protect the crown and root system from winter freeze and thaw cycles.
Mulching prevents heaving, discourages weedy growth and retains soil moisture. Remove mulch in early spring when new growth begins to emerge.
Pests
Hostas attract several destructive pests that ruin the appearance of your plants and damage roots even destroying plants completely.
Slugs and snails snack on foliage leaving holes and streaky, silvery trails. Nematodes also feed on leaves causing yellowing and brown streaking. Voles are rodent pests that feast on the fleshy roots of your hosta plants.
Disposing of foliage in autumn removes the food source for mollusks and nematodes. While slugs are more often prevalent in spring, they do overwinter under decaying wood and leaves.
Voles also use dead leaves as winter shelter and the perfect hiding place to access the lush root system.
Keep the area around your hostas free of fallen tree leaves in autumn and instead, cover plants with mulch after hosta leaves are removed. Exterminating voles may require traps or repellents.
Watering
Hostas won’t require much irrigation after foliage dies back, but the root system needs protection during the freeze/thaw cycle and watering is one of the best ways to provide it.
Frequency depends on your climate and in areas with mild, wet winters, you may not need to water at all.
Regardless of where you live, give hostas a deep soaking once every one to two weeks throughout autumn months up until the first frost. Water at ground level in the morning.
Overwintering Hostas in Pots
Container-grown hostas often enter into dormancy a bit earlier than garden-grown plants. The first choice for overwintering potted plants is to move them into an unheated garage or shed when temperatures drop below 40°F.
If an indoor location is unavailable move containers to a sheltered area and cover them with plastic sheeting or dried leaves.
Keep plants fairly dry and water sparingly only if temperatures remain above 50 degrees F. for several days.
Autumn Care Tips For Hostas
- Withhold fertilizer after late summer to reduce new growth vulnerable to winter damage.
- Late in the season remove spent leaves and cut any new foliage back to the crown.
- Keep plants free of fallen leaves and debris up until the first frost.
- After or close to the first frost cover plants completely with a layer of straw or pine needles.
- Continue a watering routine until frost then water sparingly, just enough to keep the root zone moist.
FAQ
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Removing spent leaves and cutting back your hostas helps prevent potential problems. Any new growth is subject to damage from winter freezing. Debris from old leaves makes a good hiding place for pests like slugs and voles.
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It’s fine to divide hostas in autumn and you may need to do so when plants outgrow their designated spots. But most gardeners split hostas in spring when new growth begins.
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Mowing over hostas poses the risk of damaging the plant’s crown or any buds resting close to the soil surface. Unless you need to trim back a large patch, it’s safer to do the shearing with a hand tool.