Hosta lilies are American gardeners favorite shade-loving perennials because they're so easy to grow and maintain. Established plants can divided and transplanted to other areas in the landscape or garden and shared with friends.
Here's some helpful tips on dividing and pruning hosta lilies...
Pruning Hosta Lily Plants
Except to remove spent flower scapes (stems) and damaged or dead leaves, hosta lilies do not require pruning. To remove a spent flower scape simply cut it off at its base. When plants have gone dormant in winter, dead foliage can be removed though this isn't necessary as we usually cover it with a fresh coat of mulch in spring.
Dividing Hosta Lilies
When given sufficient room to grow, there's really no need to divide hosta lilies. They naturally grow larger every year. So, I only divide hosta lilies when there's a reason to do so. Otherwise, I leave them alone. If you want more hostas to transplant to other areas of the landscape, or if your plants have outgrown the space they were intended to fill, these are good reasons to divide hostas. Keep in mind that when you dig a hosta lily to divide it, you'll be setting it back several years in maturity.
When To Divide Hosta Lilies
Hosta lilies can be divided in spring or fall:
Dividing Hosta Lilies In Spring
Spring is when I always divide hosta lilies. You want to divide hosta lilies in spring from a point in time when the eyes (spikes) start to emerge and before the leaves unfurl.
Dividing Hosta Lilies In Fall
In cooler, northern climates the time to divide hosta lilies is in September. In the South, it's October. You want the weather to be cool and moist.
How To Divide Hosta Lilies
If you want more hosta lilies to transplant to other areas, or to increase the size of the existing hosta bed, or you want to share some with friends, here is how you divide them.
If you just want to share a piece of a specific hosta variety with a friend, simply use a sharp spade or shovel to dig down and remove one or more of the outermost eyes of the plant. This is best done in spring.
If you want to increase the size of your hosta patch, dig the entire plant and quarter it, spacing the divisions further apart in the planting bed. How far you space the divisions will depend on the hosta variety and how wide it grows over a period of time. I usually space plants at a distance of the listed mature width of the plant. If the hosta grows to 3 feet wide, I space the divisions 3 feet.
Dividing The Plants
if the weather has been dry, it's best to soak the soil around the hosta lily you intend on dividing. Do the soaking the day before so you're not digging in mud.
When digging your hosta, keep in mind that the more roots you keep the better.
When digging, start by using your spade or round point shovel to dig a trench around the perimeter of your hosta lily. Dig at a good distance from the perimeter of the clump to get as many roots as possible.
After digging the perimeter trench start to dig under the roots. The roots of small hostas may only be 6 to 8 inches deep. The roots of larger hostas can be as deep as 18 inches. Dig around and under the roots prying as you go until you can lift the entire plant with root system in tact.
Dividing The Eyes
After having dug the clump, you can divide the eyes.
If you have a large clump of 20 eyes or more you can choose to third or quarter it, which won't set the plant back too much. Or, if you want more transplants, you can divide it into smaller sections, even down to individual eyes. Just know that the smaller the divisions the longer it will take for them to mature.
Some hosta varieties are easier to divide than others. To find out, shake as much of the dirt off the roots as possible. Then try to pull the eyes and their roots apart. If this doesn't work, you'll have to use a heavy knife to cut them apart to avoid damaging the hosta eyes.
Dividing With A Knife
Step 1
Top divide the eyes, place the hosta on a flat and solid surface.
Step 2
Then, using a heavy duty knife, make your cuts between the eyes. When making a cut, try to avoid slicing the eye itself.
Planting Your Divisions
When you are replanting your hosta divisions, plant them at the same depth they were prior to digging the mother plant. Plant them as you would when planting container grown hostas.