Dividing Hostas: A How to Garden Guide for Success

If you want to make the most out of your hosta plants, dividing them can significantly increase their presence in your garden and keep them thriving.

In this article, you’ll learn the optimal times and techniques for dividing your hosta plants to promote healthy growth and maximize their visual appeal.

Understanding the best practices for hosta division is important for maintaining the health of your plants, and the information presented here will guide you in achieving that goal.

Why Do We Divide Hostas

Dividing hostas promotes their growth and rejuvenates the clumps, resulting in healthier and more robust plants.

This also allows you to multiply your hosta collection, as the process creates additional plants for your garden or to share with friends and fellow gardeners.

By understanding the importance and benefits of dividing hostas, you can make informed decisions on managing your plants and optimizing their growth in your garden.

How Often Should I Divide Hostas

Dividing hostas can help you maintain a healthy garden, but how often should you perform this task?

Dividing your hostas every three to five years is the most commonly recommended period. But is it good information?

Some hostas grow almost as well as the weeds, and 3 to 5 years is fitting here.

You don’t need to divide hostas too often, as they are resilient plants. Generally, hostas need to be divided every five to ten years. This is sufficient to maintain their size and promote healthier growth. This is fitting advice for most hostas.

What about large hostas, especially giant hostas 3 feet tall and 5 feet across? It takes time to get there, 5 years, 7 years, or more. These plants are most likely at their best at five to ten years old. Don’t you want to enjoy it as long as possible?

A set number of years for splitting the plants is a helpful guideline. But your plants will tell you when they need to be divided.

Divide your hostas when they get too big for the location when they start crowding other plants, when their shape looks bad, when sections start dying out…

Let them grow and flourish. When there is a reason to divide them, then do it.

When to Divide Hostas

When it comes to dividing hostas, timing is key. While some gardeners choose to divide their hostas in the spring, doing this task in late summer or early fall is often more beneficial.

While dividing hostas in spring and fall is ideal, these plants are generally quite robust. They can be divided at other times during the growing season if necessary. Just be sure to take extra care when replanting and watering the divisions.

Dividing Hostas In Spring

Overall, dividing hostas in the spring is an excellent way to rejuvenate the plant, propagate new plants, and control its size.

The timing allows for optimal growth and recovery. It reduces the stress on the plant, which can lead to a healthier and more vibrant plant.

From the time you first spot their “eyes” popping up through the soil until the leaves begin to unfurl, you have about a month to divide them.

This will provide you with smaller plants that are easier to divide and avoid damaging leaves. Remove the injured leaves if a few are damaged during the process.

Dividing Hostas in Summer

Although hostas are tough plants and can be divided at any time during the growing season, dividing them in summer is not recommended.

The foliage has increased water demand, and the root system may suffer from reduced moisture availability. Additionally, the larger, fully-grown leaves make dividing hostas more difficult.

Temporary man-made shade in a frame covered with shade cloth can reduce stress on the new divisions.

Dividing Hostas in Fall

Fall is an excellent time to divide hostas because the plant is starting dormancy, and the cooler temperatures and increased rainfall provide optimal conditions for root growth.

The cooler weather, combined with the warm soil temperatures and typically increased moisture availability, provide ideal conditions for root growth.

Yes, warmer soil. The sun has spent all summer slowly warming the ground.

Just finish splitting the plants at least 4 weeks before the first frost. I prefer to finish about 6 weeks before the expected frost arrives.

This time frame will give the divisions time to establish themselves before winter.

Best Time to Divide Hostas by Planting Zone

I briefly touched on how your location will affect the best time to divide your hostas, even though fall is the best. The following chart will outline the planting zones that are pertinent to hostas. There are more, but some aren’t suitable for supporting this plant’s growth.

How to Divide Hostas

In this section, you’ll learn the step-by-step process for dividing hosta plants. Understanding these tips and techniques will help ensure the success and health of your divided hostas.

Water the Hosta

Start by thoroughly watering your hosta plant one or two days before you divide it. This will ensure that the plant and its root system are well-hydrated, which makes the division process less stressful for the plant.

Dig Up the Entire Clump

Using a spade or fork, carefully dig a circle around the hosta, starting about 10-35cm (4-18 inches) from the base, depending on the plant size.

Gently slide the tool underneath the clump, avoiding damaging the crown and roots. Lift the entire clump out of the ground.

Remove Excess Soil

Shake, brush, or hose off any loose soil from the root system so you can clearly see the structure of the hosta. This will make identifying where to make the divisions easier and avoid damaging any buds or stems.

Cut the Clump into Pieces

Cut the root system into smaller sections using a sharp knife or garden shears, ensuring that each division has a healthy crown and roots. Be cautious to minimize any damage to the roots or leaves.

Clean and Soak the Divisions

Once you’ve created the divisions, rinse off any remaining soil and remove any damaged or soft roots.

Trim off any dead foliage and remove any adhering weeds.

Soak the roots in a bucket of water for 5 to 10 minutes to ensure they’re well-hydrated before transplanting. This will help support new root growth in their new location.

Plant and Water the Divisions

Plant the divisions with the crown just above the soil surface. Remember, hosta roots like to spread out, not go down so much.

Water thoroughly, providing adequate moisture for the newly divided plants to establish themselves.

Post Division Care

During the initial weeks after transplant, monitor your hostas for signs of stress or issues caused by crowding, such as poor growth or yellowing leaves.

If you notice any problems, adjust the planting as needed or consider relocating the plants to a more suitable spot.

Quick Note About Hostas and Viruses

Most people don’t clean or sterilize their tools before they use them to cut through the hosta clump and divide the plants. However, doing so can reduce the risk of transferring diseases and viruses.

Should you sterilize your garden tools?

This is your decision. Critical times for introducing problems are when new plants are added or when working with struggling (sickly) plants.

If you sterilize your tools, the two easiest-to-use disinfectants are chlorine bleach and ethanol or isopropyl alcohol.

Use 10 percent chlorine bleach (1 part bleach to 9 parts water) and soak for 30 minutes. Rinse well afterward, as the bleach is corrosive. Works great for large tools.

Use 70 percent or stronger ethanol or isopropyl alcohol straight out of the container as a dip or wipe. Works great and is cost-effective on small tools.

Tips for Dividing Large Hosta

Dividing a large hosta is similar to dividing smaller plants. Mostly just more work.

First, it’s important to reduce stress on your hosta plant. Water it thoroughly if it hasn’t rained in the past day or two.

The work is much easier if you start by cutting back the foliage. Some or a lot is going to get damaged anyway.

Having a helper to get the plant out of the ground makes the job easier and can save your back.

As with any other hosta, work some of the soil out of the clump without causing much damage.

Take your time making the divisions. You usually have lots of choices. Soaking the divisions before planting is still important.

How to Divide Hostas in Containers

After digging and dividing hostas in the ground, you will find dividing hostas in containers a snap.

The same general rules for dividing hostas apply here. So, I will try to confine my remarks to what is unique to the division of hostas in containers.

The only tool you need for smaller pots is a pair of shears. If you have giant pots, you may need a spade or a fork and the more conventional steps above.

Knock the plant out of the pot. For stubborn plants, tap the container’s rim on a solid object.

 Shake the plant carefully to remove the potting soil from the root ball.

If that doesn’t work, lay the plant on its side and roll it back and forth a few times with light pressure on the root ball. Now most of the potting soil should fall off with a few shakes. 

Use your fingers and strip out the rest of the potting media and detangle the roots.

Now you can divide the hosta as you desire and repot similarly to a bare root hosta.

Frequently Asked Questions

As you learn about dividing hostas, you may have several questions regarding the process and how to ensure success. This section will address some of the most common inquiries, helping you understand why dividing hosta plants is important and improving your gardening skills.

How small can I divide hostas?

Typically, each division should have a healthy root system and at least one or two growing points or “eyes” to ensure successful growth. Small divisions can have a much lower success rate depending on your skills.

Can you divide hostas in their second year?

While it is possible to divide hostas in their second year, disadvantages exist. Dividing hostas in their second year may result in smaller divisions, which can take longer to establish and grow into mature plants.

How late can you wait to divide hostas?

Suppose you plan to divide hostas in the fall. In that case, it is important to do so at least 4-6 weeks before the first expected frost to allow the plant enough time to establish itself before winter sets in.

What tools do I need for dividing hosta plants?

Having the right garden tools is essential for dividing hostas effectively. You’ll need a sharp spade or a garden fork, a garden knife, a bucket of water, and a garden hose. Additionally, have a tarp on hand to minimize mess.

What is the proper depth for planting divided hostas?

When transplanting divided hostas, ensure that the planting depth is similar to the original depth of the root clump. This will promote good drainage and avoid exposing the roots to air pockets or drying out.

How do I prevent damage to the rhizomes during division?

Take care when dividing hosta plants to avoid damaging their rhizomes. Use a garden knife to make clean cuts, and if needed, soak the root clump in a bucket of water to soften the soil and make separation easier.

What should I do with the removed dead portions of hostas?

When you come across dead portions during division, remove them promptly to promote a healthier plant. Dispose of them carefully to prevent the spread of pests, such as slugs and snails.

What are the benefits of dividing hostas in the spring?

Dividing hostas in spring, when shoots are just emerging, helps prevent water stress by allowing the plant to establish itself in cooler temperatures. This also minimizes damage to the foliage, encouraging more robust growth.