Hostas are a staple in many gardens, thanks to their lush, wide leaves and ability to thrive in the shade.
Whether you’ve got a small collection of hostas or a large hosta garden, these hardy perennials need a bit of care in the fall to make sure they survive the winter and come back strong next spring.
September is the ideal time to start preparing your hostas for the cold months ahead.
I’ve been growing hostas for years, and over time, I’ve learned that a little preparation in early fall makes all the difference in how well they handle winter.
From proper pruning to keeping pests at bay, there are a few key tasks to focus on.
This guide will walk you through everything you need to do to ensure your hostas make it through the winter healthy and ready to thrive again when the weather warms up.
Start by Cleaning Up Dead and Damaged Leaves
As September rolls in, one of the first things you should do is start cleaning up any dead or damaged leaves around your hostas.
Hostas are prone to leaf damage by the end of summer, whether from slugs, sun scorch, or just general wear and tear.
This is perfectly normal, but leaving these damaged leaves on the plant can invite pests and disease over the winter.
I always start by removing the worst of the damaged leaves.
Use a clean, sharp pair of garden shears or scissors to cut them off at the base of the plant.
Make sure you dispose of any infected leaves far away from your garden to prevent any diseases from spreading.
In my early gardening days, I didn’t realize how important it was to clean up around my hostas in the fall, and I paid the price.
One year, I left a pile of decaying leaves near the base of the plant, and it became a breeding ground for slugs.
Since then, I’ve always made sure to keep the area around my hostas clean and tidy as we head into winter.
Don’t Prune Hostas Too Early
While it’s tempting to start cutting back all of the leaves once fall begins, hold off on a heavy prune until your hostas have fully started to go dormant.
In September, your hostas are still storing energy for winter, and cutting the leaves too early can weaken the plant and reduce its ability to survive the cold.
Hostas will naturally die back as the temperatures drop.
Once you see the leaves turning yellow and starting to wither, you’ll know the plant is ready to be cut back.
I usually wait until the first frost has killed off the leaves before I go in with my pruners.
When you do cut them back, trim the leaves down to a few inches above the ground.
I find this helps keep the plant tidy and reduces the chance of rot setting in over the winter.
Back when I first started growing hostas, I made the mistake of cutting them back too early, thinking I was getting ahead of the winter prep.
The result was that my plants struggled to bounce back in the spring.
Since then, I’ve learned to be patient and let the plant naturally go dormant before cutting it back.
Mulch to Protect the Roots
Hostas are fairly hardy, but they still benefit from a good layer of mulch to insulate their roots through the winter.
Mulching helps to regulate soil temperature and prevents the freeze-thaw cycle that can heave the roots out of the ground.
In September, once you’ve cleaned up around your hostas, apply a 2-3 inch layer of organic mulch around the base of the plant.
I like to use shredded leaves, straw, or pine needles, as they break down over time and enrich the soil.
Just be careful not to pile the mulch directly against the crown of the plant.
Leave a little space around the base to avoid trapping moisture, which can lead to rot.
In my garden, I’ve found that mulching makes a huge difference in how well my hostas handle winter.
The year I forgot to mulch, I had several plants that didn’t come back as vigorously in the spring.
Now, it’s a step I never skip.
Water Your Hostas Deeply Before the Ground Freezes
Even though hostas go dormant in the winter, they still need a good amount of moisture in the fall to get through the colder months.
In September, make sure you’re watering your hostas deeply to ensure their roots are well-hydrated before the ground freezes.
I’ve found that a deep watering once a week works well in the fall, especially if the weather has been dry.
You want the water to reach down to the root zone, so give the plant a good soak, but don’t let it sit in standing water.
Once the ground freezes, your hostas won’t be able to take up any more water, so it’s important to get them well-watered before that happens.
A well-hydrated hosta is much more likely to survive the winter and come back strong in the spring.
Back when I was new to gardening, I didn’t realize how important fall watering was.
One particularly dry autumn left my hostas struggling through winter, and the next spring, they looked weak and sparse.
Since then, I’ve made a point to water them thoroughly throughout September and October, and they’ve been much healthier ever since.
Consider Dividing Overcrowded Hostas
September is also a good time to assess whether any of your hostas are becoming overcrowded.
Hostas can grow quite large over time, and if they start to crowd each other out, they may struggle to thrive.
If you notice your hostas are getting too large for their space, consider dividing them in September before the ground freezes.
Dividing your hostas gives the plants more room to grow, and it can also give you extra plants to spread around your garden.
I usually divide my hostas every few years to keep them healthy.
Use a sharp spade or garden fork to dig up the entire clump, then carefully separate the roots into smaller sections.
Each section should have a good amount of roots and at least a few stems.
Replant the divided sections immediately, spacing them out to give each one plenty of room to grow.
Water them well after replanting, and apply a fresh layer of mulch to help protect the newly divided plants over the winter.
I’ve had great success dividing my hostas in the fall.
Not only do they come back stronger in the spring, but I also love having extra plants to share with friends or fill in bare spots in the garden.
Keep an Eye Out for Pests
Even though the weather is cooling down, pests like slugs and snails can still be a problem in September.
These pests love to feast on hosta leaves, and they can cause serious damage if left unchecked.
As you’re cleaning up around your hostas, keep an eye out for any signs of pests.
If you notice holes in the leaves or slime trails, it’s likely that slugs or snails are lurking nearby.
There are a few ways to deal with these pests in the fall.
You can hand-pick them off the plants, set out beer traps, or use an organic slug bait to keep them at bay.
I’ve found that a combination of these methods works best in my garden.
I remember one year when I didn’t bother checking for slugs in the fall, and by spring, they had completely shredded the new hosta leaves as soon as they emerged.
Now, I make sure to do a thorough pest check in September, and I haven’t had that problem since.
Protect Hostas from Frost Heaving
One of the biggest dangers to hostas in the winter is frost heaving, which happens when the ground freezes and thaws repeatedly.
This can cause the roots of your hostas to be pushed up out of the ground, exposing them to the cold and damaging the plant.
To prevent frost heaving, make sure your hostas are well-mulched in September.
The mulch helps to keep the soil temperature more consistent, reducing the chances of the freeze-thaw cycle that leads to heaving.
In areas with particularly harsh winters, you may also want to consider adding extra mulch later in the fall, especially if you notice any roots starting to become exposed.
One winter, I lost a few hostas to frost heaving because I hadn’t mulched thickly enough.
It was a tough lesson to learn, but since then, I’ve made sure to apply plenty of mulch, and I haven’t had any issues with heaving since.
Let the Leaves Die Back Naturally
As your hostas go dormant in the fall, the leaves will start to yellow and die back.
While it may be tempting to cut them back immediately, it’s best to let them die back naturally.
The leaves are still providing energy to the roots, even as they turn yellow.
By leaving them in place until the first frost, you’re allowing the plant to store up as much energy as possible for the winter.
Once the leaves have completely died back, you can cut them off and clean up the area around the plant.
I usually wait until after the first frost to do this, as it ensures the plant has fully entered dormancy.
In my early days of gardening, I used to cut back my hostas as soon as the leaves started to turn yellow.
I didn’t realize that this was cutting off the plant’s energy supply too early.
Now, I’m more patient and wait until the leaves are fully dead before cutting them back, and my hostas have been much healthier for it.
Protect Potted Hostas from Freezing Temperatures
If you’re growing hostas in pots, they’ll need a bit of extra care to survive the winter.
Potted hostas are more vulnerable to freezing temperatures because their roots are above ground and more exposed to the cold.
In September, start thinking about how you’ll protect your potted hostas once the temperatures drop.
You can move them to a more sheltered spot, such as against a wall or into a garage, where they’ll be protected from harsh winds and frost.
If moving them isn’t an option, you can wrap the pots in burlap or bubble wrap to insulate the roots.
I’ve had great success with this method in my own garden, and it helps prevent the soil from freezing solid.
Back when I first started growing hostas in pots, I lost a few to freezing temperatures because I didn’t realize how vulnerable the pots were.
Since then, I always make sure to provide some extra insulation, and my potted hostas have been thriving.
Final Thoughts
Hostas are tough plants, but a little care in September can go a long way in ensuring they survive the winter and return strong in the spring.
From cleaning up damaged leaves to mulching for root protection, these simple tasks will help your hostas thrive even through the coldest months.
Over the years, I’ve learned that the effort you put into preparing your hostas for winter is well worth it.
When you see those lush, green leaves emerging again in the spring, you’ll know that your hard work paid off.
So, as September arrives, take some time to care for your hostas.
With the right preparation, they’ll come through the winter healthier than ever, ready to beautify your garden for another growing season.