Hostas are one of the most versatile and easy-care perennials you can have in the garden, and dividing them is a great way to get more. Though they do have some needs and features to be aware of—for example, deer love to eat them, and most varieties won't flourish in full sun—they're generally very straightforward to plant and care for.
Hostas tend to increase in size each year and so they benefit from regular dividing. This is also one of their desirable qualities, as you can get many hostas from one plant over time, with plenty of extras to share with gardening friends. Dividing hostas is usually fairly easy, and doesn't require any special skills, but there are a few things to keep in mind.
When to Divide Hostas
Timing is an important consideration here; should you divide in spring or fall? While theoretically you could do either, or even in summer when the plants are in full growth, it's best to divide when the plants have gone mostly dormant. In spring, the young hosta buds and leaves can be easily damaged while dividing, and this affects how they look during the growing season. Dividing and replanting in fall also gives the plants plenty of time to adjust to their new location before forming new growth. The only drawback to dividing dormant hostas is not necessarily being able to recognize the variety. Creating a labeling system with bags, sticks or other markers will help.
Before Getting Started
Dividing hostas is pretty easy so you don't need any special preparations. Dividing not too long after a rainfall means the soil will be softer and make things easier, which is important if the clump you're dividing is big. You'll want to choose where you're replanting, and prepare those holes in advance, but it's not necessary to plant them immediately after division. Adding some new topsoil with compost will give them a good start, so make sure you have some on hand.
Equipment / Tools
- Garden knife
- 1 inch topsoil or compost
Dig Up the Clump to Be Divided
Some gardeners divide hostas by just digging out a chunk of them from the planted clump. This works, but it's easier to clean up the roots if you dig up the entire clump first. Using a shovel or pitchfork, go around the entire clump and sig in about 6-12 inches from the crown of the plant.
Divide the Clump
This is the main task in dividing hosta plants: the actual splitting of the clump into divisions. Depending on how large it is, you can make a number of small or large divisions. Try for divisions that are at least six inches in circumference, as these will produce a good sized beginning plant in its new location. You can divide this with your flat or rounded shovel, or try using a garden knife for smaller plants.
Trim and Clean the Divisions
Once you've divided the plant, you'll want to clean up the divisions. Make sure to remove any stray weeds that are intertwined with the roots. In addition to pulling them out you can hose off the roots to catch any tiny stray root fibers. Also remove large clumps of clay soil which can impede drainage. You can also trim off any dead leaves or damaged portions of the plant. But if you do damage any buds or leaves, don't worry: it won't cause any long term harm, it will just affect the current season of growth.
Replant the Divisions
Planting hostas is very easy, as they're just not very demanding. You can even leave the divisions out of the ground for a while until you decide where to plant them, but keep them out of the sun and keep them watered. When you're ready to plant, prepare the hole. Make sure there's plenty of room for the root system, and add a layer of compost or rich soil to give them a good start. Hostas grow fine in clay soil but it's much easier to divide them if they have loamy soil and good drainage, so keep this in mine when planting.
Fill in the hole with soil and give them a good drink of water. If the weather is dry or hot, water them regularly (every other day or so) to keep them vibrant. Your hosta divisions will take root quickly and, before you know if, it will be time to divide them again!