Daylilies (Hemerocallis spp.) are reliable bloomers, demanding little from the gardener and rewarding with lasting color.
There are cultivars suitable for cultivation in Zones 3 to 9, and much of the time you don’t have to worry about them in winter – or at all.
But if you live somewhere with frigid or very wet winters, or you’re growing a cultivar that isn’t suited to your region’s USDA Hardiness Zone, it’s a good idea to do some winter preparation.
Ideally, you should dig up the rhizomes – sometimes referred to as tubers – and store them over the winter months, planting out again in spring.
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If you’ve ever purchased daylily tubers, they were probably stored for months before they reached you, so you don’t need to worry about the uprooted rhizomes surviving a few months out of the ground, as long as you prepare them properly.
Before we get our hands dirty, if you need a refresher on how to grow and care for dayliles, check out our guide. Then come back here, and we’ll get to business.
Are you ready to get your hands dirty? We’re going to dive right into the following topics:
How to Overwinter Daylilies
When to Winterize Daylilies
The only time you need to do anything for daylilies in the winter is if you are growing them in a USDA Hardiness Zone that they aren’t suited to.
You can find daylilies suitable for climates all the way down to Zone 3 and up to Zone 9, so in most temperate areas, they’ll do just fine.
You can add an inch or two of organic leaf litter or wood mulch over the area to help reduce frost heave and damage, but they don’t need any additional care beyond that.
But perhaps you picked a beautiful cultivar that is rated for Zone 6 and you live in Zone 5, you may be able to leave them in the ground, topped with three inches of mulch covered by a layer of cardboard, but it’s risky.
In this case, or if you’re growing them as annuals, it’s much better to dig up and store them for the winter months.
The other time it’s advisable to dig them up is if you live in an area with soggy, wet winters.
The nonstop rain can lead to saturated soil that drowns the tubers, causing rot and even death. So even if you live in a warmer region, it’s a good idea to lift them if you experience a lot of rainfall.
Don’t lift the rhizomes too early in the year. You want to wait until the first hard freeze is on the horizon. We want to remove the tubers before the ground freezes and winter takes hold.
Lift the Rhizomes
When you have the timing right, the first step is to dig up the tubers.
To do this, cut down any remaining leaves to the ground. Next, use a shovel to dig a wide margin around the leaves, at least four but preferably six inches, to ensure you don’t damage the root system.
Dig about six to eight inches deep and then take the shovel and gently wedge it upwards to lift the clump from below.
Once you have your clump out of the ground, gently knock or brush away the dirt surrounding the roots.
If your plants are over two years old, you may want to divide your daylilies at this point. To do so, gently tease apart the clump into equal sized pieces.
We have a guide to dividing daylilies if you’d like a more indepth look at the process.
Before setting them in storage, make sure you remove as much of the dirt as possible from the plant material.
Trim what remains of the foliage further if the leaves are longer than an inch. Inspect the rhizomes and cut off any diseased or rotting tissue.
If you used a hose to rinse the soil off the roots, make sure that the rhizomes are dry before putting them into storage.
Storage
Now that you have the tubers out of the ground, you need to put them in storage. Grab yourself a cardboard box and some straw or sphagnum moss.
Lay about three inches of the material in the bottom of the box and set the rhizomes on top, spreading them out if possible. Cover them with a layer of three inches of additional material.
If you wish, you can put another layer of tubers on top of the first layer, but in this case, cover the lower layer with an extra inch of straw or sphagnum moss to ensure the layers won’t touch.
You can keep three or four layers of rhizomes in each box. Just be sure to top the final layer with about three inches of material.
Keep the box in a cool, dark area. You want the temperatures to be above freezing but below 50°F if you can manage it. That means an attached, unheated garage or basement is probably ideal.
They will be quite happy all winter provided that you prepped and are storing them properly.
Spring Planting
When the last predicted frost date has passed and the ground has thawed, you can put the tubers back in the ground.
Don’t worry if they’ve started to sprout while in storage, that happens sometimes. Just make sure you get them into the soil before the leaves are six inches long.
If they start growing too long, and the conditions are still not suitable for planting out, put them in a container filled with potting medium and place it in a sunny spot near a window while you wait to plant.
Prepare the planting area by digging in some well-rotted compost and then dig a hole deep enough to bury the top of the tubers by an inch.
Gently lay the tubers in the hole with the leaf section facing upwards and cover with the soil you removed. Water well.
Container Care
If you keep your daylilies in containers, cut any existing dead or alive foliage back to the ground and move the container into an attached garage or basement.
Anywhere that stays below 40°F but doesn’t drop below 30°F and is protected from wind and excessive moisture is ideal. Let the soil dry out completely between watering.
If you don’t have extremely soggy winters, you can even leave the pots in place and just cover them with a few layers of frost cloth.
Just keep in mind that you should treat your container-grown plants as though you live in one Zone colder than where you are.
So if your daylilies are suited to Zone 5, you would need to live in Zone 6 to keep them in a container outside.
Daylilies for Days
As easy as daylilies are to grow in the garden, overwintering them is pretty darn easy, too.
Some plants need special care and pampering to survive winter indoors, but you can basically dig daylilies up and forget about them until spring rolls around.
What kind of daylilies are you growing? What Zone are you in? Let us know in the comments!
And for more daylily know-how, we’ve got plenty of guides to keep you busy! Have a read of these ones next:
