How to Divide Hostas
Hostas are the workhorse of the shade garden. These extremely hardy perennial plants can add a punch of green, yellow, blue or white to the shadiest areas of the garden. Hardy in Zones 2 – 10, they are quite flexible when it comes to soil type. They require little fertilization, and annual maintenance is almost non-existent. In all honesty, there are few perennials that are easier to grow. They are also one of the easiest to propagate by division.
Should You Divide Your Hosta?
Hostas can go for years without needing to be divided, but if the center of your hosta begins to die out or if the plant doesn’t seem to be thriving, it is a good sign that it needs to be divided.
They can also be divided if you want to add more of the plants throughout your garden or if you’d like to share the plant with friends and family. Division is a free easy way to make more of these hardy shade tolerant plants.
When to Divide Hostas
There are several schools of thought as to when it is acceptable to divide your plants. Some say in the spring when the plants first start showing their eyes, others say in the fall as they get ready to become dormant for the winter, and others say anytime with in the growing season. So when IS the best time to divide them? I cast my vote for the spring, when it’s the easiest, for several reasons:
- The plants leaves aren’t open to get in the way while digging.
- The rain in the springtime will make the soil easier to dig.
- The spring rain will also help give the new plant plenty of water to help them to establish after division.
- Any kind of manual labor is easier in the cooler temperatures of spring then in the hot months of summer.
How to Divide Hostas
You will only need one tool: a flat spade. If you are interested in making multiple plants, you may also need a heavy kitchen knife. Keep in mind though, the more divisions you make from your plant the further back in the growing cycle you set it. Although the divisions will all grow, it could take several years to create the mature hosta you had before division.
As stated earlier, division is simple, but for a higher success rate you may want to start by cutting out the outermost eyes as to not disturb the main clump of the plant. So before you begin, you need to decide where you will dig. The photo has a circle in the center of the plant where it has died out. The arrows show the plant’s eyes emerging around the hosta's center. The best place to divide it is around the outside of the plant and through its now dead center.
Once you’ve decide where you will dig, just put your spade into the ground around the outside of the area and dig down and around the area. Depending on the plant’s cultivar the roots can be anywhere from 6 – 18 inches deep. Dig a circle with your spade around the part of your plant as you attempt to loosen it from the soil. Basically you are using the leverage of the spade to slice into the ground around the area you will transplant until you are able to pull out the plant.
Now that you’ve removed your hosta, you have a couple of options as to what to do with it.
If you are just going to replant the division somewhere else in your garden, prepare the soil where you are going to put it by digging a hole that is twice the circumference of the division. Plant the division in your hole, cover with mulch, and water.
If you want to make multiple propagations of your plants, you should rinse the dirt from the roots. First try to separate the individual rhizomes by hand. If you can’t, divide them with a kitchen knife, try to make as few cuts into the plant as possible. Once you have all your divisions, you can then plant them individually or put them in a pot with some soil to give to friends.
Tips and Tricks
- Make sure to water the newly planted hosta frequently or the plant may not establish into its new space in the garden. A good rule of thumb is about an inch of water a week for the first 2 weeks.
- If you notice that your new plants beginning to wilt at any time in the first few weeks following division, water them more frequently: once or twice a day.
- If you don’t have time to plant your new hosta right away, make sure the roots of the plant stay wet. If they happen to dry out a bit, soak them is a bucket of water for a couple of hours before replanting.
- Hostas between 3 – 8 years old make the best divisions. At 3 the plants are mature enough to be divided, but by 8 the clump will be so dense that dividing will be difficult.
- The window for dividing them in the spring is about 4 weeks long. When the eyes start to emerge and the soil is warm enough as to not damage the roots.
- If you are dividing them at a time when there has been very little rainfall, water the plant a day before you divide it.