Horticulture Magazine

When (And How) To Split Hostas

close up of hosta leaves

Hostas are incredibly useful plants to grow in your garden and knowing how and when to split them makes it easier to keep them healthy and increase your collection.

They are a well known ornamental shade plant. This plant is commonly grown for its attractive foliage, which can come in a range of different hues and with variegation.

Fewer people are aware that hostas are also a very useful (and tasty) perennial vegetable. All hostas can be eaten. The rolled-up leaves which emerge in spring are great in stir-fries, young leaves are great in salads and older leaves can be used as a versatile cooked green.

So if you have some shady or partially shaded spots in your garden, hostas can be an excellent choice. Though beloved by slugs and sometimes troubled by these pests, they are generally relatively low maintenance and easy plants to grow.

Beautiful variegated forms bring variety and interest to shaded garden spots.

One thing to think about when growing hostas, however, is division. Splitting your plants serves two important purposes. Read on to find out more.

various types of hosta with green, white, blue, and yellow foliage and mulch in the foreground

Why Split Hostas?

Hostas are split for two main reasons.

The first is to prevent overcrowding in perennial planting schemes and keep mature plants healthy. Hostas spread to form large clumps over time, and may outgrow the position in which they were initially placed.

When a hosta plant grows large, it can become crowded, and may reduce in vigour as it outstrips water and nutrient resources available.

Other plants in the vicinity may also suffer when perennial plants in mixed plantings are not divided.

Like many other herbaceous perennials, hosta should be divided to keep the parent plant in good health.

But splitting hostas and other herbaceous perennials also serves a second purpose:

It allows you to propagate new plants – and is an incredibly easy and completely free way to do so. When you split hostas, you get free new plants to place elsewhere in your own garden, or to give, perhaps, to family or friends.

Dividing hostas and other existing perennial plants in your garden is also a more sustainable and eco-friendly solution when populating new beds or filling new garden areas.

Since you will not have to purchase any new plants in plastic pots, you can reduce your negative impact on the environment.

If you are new to plant propagation, then dividing perennial plants like hostas is a very simple, straightforward place to start.

When To Split Hostas

Summer-flowering plants, including hostas (even when flowers are not produced on all cultivars), are best divided in spring (March to May) or in the autumn (September to November).

If the autumn is particularly wet, it may be better to delay division until the spring. You can also split hostas over the summer, but the strain on the plants will be increased during hot and dry weather.

You can split mature hostas to make new plants any time after an existing clump is well-established. For health and to prevent overcrowding, you will usually split hostas every 4-5 years.

Hostas grown in containers may obviously outgrow their containers and need to be split more frequently.

How To Divide Hostas – Step By Step

hostas being divided by hand

To uproot and divide a mature clump of hosta:

  • Use a garden fork or other implement to gently pry the clump up from the ground or its container. Try to retain as much of its root system as possible.
  • Gently shake off excess soil so that you can see the root system more clearly.
  • Carefully tease the roots apart with your hands to separate it into sections. This is usually rather easy with a plant that has fibrous root systems like hostas. You should not need to use a spade or other sharp implement as you will do when dividing more woody rooted perennials. You may simply wish to split the clump in two, replanting one section and finding space elsewhere for the other.
  • If you are interested in making new plants, you might separate the clump that is not to be replanted into a series of smaller divisions. If you do this, make sure each section has some roots (as much root system as possible) and 1-3 good buds in the above ground portion of the plant.
  • Replant the division that will remain in place, carefully placing it back into the soil and firming the soil around it. Mulch around it with organic matter.
  • Plant out or pot up the portions you have split from the parent plant as soon as possible, taking care to make sure they do not dry out.

If you have a large hosta clump, you can also consider leaving the bulk of the plant in place.

Rather than uprooting the whole lot, you can simply use a spade or fork to separate off a healthy portion at one side of the plant.

This portion can then be split as above, and the soil and mulch placed back around the remaining portion.

using a trowel to split hosta plants

Replanting Divisions

Once you have replanted the parent, or settled it back in place, you can turn your attention to the new plants you have made. You can replant hosta divisions in pots or containers, or replant them right away into another part of your garden.

Be sure to keep your hostas well-watered, especially until they become established. And remember that they will require more water when grown in containers, or when placed in full sun.

Remember that while some hostas can be placed in full sun, most will prefer a moist and somewhat shady site.

They can work very well in the dappled shade below fruit trees, and are an interesting edible ground cover option to think about for a fruit tree guild or forest garden. Hostas can work well when grown in mixed planting schemes beneath an apple tree, for example.

You might also grow hostas in a shady perennial border. It can work well both in ornamental schemes and in beds or borders with other perennial vegetables and herbs.

Learning how to split hostas does not take a lot of effort. As you can see from the above, it is an easy process, which will allow you to keep existing plants happy and healthy, and get more of these useful plants for your garden.

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