Late summer is a great time for dividing most perennials, and the perfect time to create a whole slew of new plants for your landscape.

And best of all, all for free!

Although many perennials can be divided anytime from early spring through fall, splitting plants in mid to late summer offers a few additional advantages.

how to divide perennials in the summer
Dividing perennials in the summer is a great way to fill you beds with plants for free!

The Advantages of Dividing Perennials In Late Summer

By splitting plants in August and early September, new starts have plenty of time to establish their roots before winter.

And that can make all the difference in a plant’s health and vitality the following spring.

Unfortunately, spring-divided plants sometimes lag behind in their first year growth.

They spend most of their energy the first few months on root development, and not on producing better foliage and more blooms.

You can easily divide over-sized perennials in late summer to create tons of new plants.

But by dividing in mid-summer, the plants have a few months to develop and store energy for the following season.

And that means they are ready to start growing and blooming as soon as the soil begins to heat up!

A Few More Reasons…

Another great advantage to dividing plants in the summer is that you are able to see a plant’s actual size at maturity.

This is huge in helping determine what plants need attention, and where!

oversized hosta plant
It can be hard to tell how large perennials will become in early spring. But as mid-summer approaches, it is easy to see what plants have become overgrown – like these hostas!

In the middle of summer, it is easy to see what plants are growing too big or thick. And, vice-versa, what portions of your flowerbeds and landscape need additional plants.

But that task can be difficult in the early spring.

Many plants haven’t even broken through the ground. And others have only reached a small portion of their final size.

But splitting and dividing in the summer makes thinning and filling areas in with more plants a cinch!

And by filling those empty spots with more plants, you cut down on future mulch costs – and more importantly, weeding! (see : How To Keep Flowerbeds Weed Free All Summer Long)

How To Divide Perennials In The Summer

Nearly all early to mid summer blooming perennials can be dug up and split after they bloom.

dividing perennials
As soon as they finish blooming, nearly any perennial, like this purple coneflower, can be dug and divided.

Here is a quick look at a few of the most common perennials found in landscape , and how to divide them in mid-summer.

Black Eyed Susans, Coneflowers & Daisies

All three of these commonly found perennials can be divided in the same method.

Cut spent bloom stems and foliage back to a few inches above the ground. Dig up and split with a sharp shovel or knife. And if you have never used a Hori-Hori garden knife, it is a great tool for this task!

dividing perennials in late summer
This large coral bell has finished blooming and is ready to be split and transplanted. Start by cutting back the spent flower stems.

Water the roots well when replanting, and every few days for the first few weeks after transplanting.

Although plants may not show much top growth during the final months leading up to winter, below the soil, their roots are becoming well-established for great spring growth!

Coral Bells

Once the tall wispy blooms of the coral bell plant have completed their cycle, cut the flowers and stems back to the plant’s base.

Keep the remaining foliage at the base, and simply dig around the edges of the plant base to lift out of the ground.

Next, split the roots and foliage with a sharp knife or spade.

splitting perennials
Split the plant with a sharp spade or knife to create new transplants.

Water the roots well at planting time and for the following weeks into late fall.

In some cases, the foliage may die back or die off, but the plant’s roots will survive and be ready to go next spring.

dividing perennials in late summer
Once split, the coral bell created four new plants

Hostas

In the middle of summer, it’s quite easy to see which hosta plant might be getting a bit too large!

Although you can dig up and replant hostas at nearly any point, waiting until after they bloom allows a little more beauty in the landscape.

Simply cut back all foliage and blooms to about an inch or two above the soil. Next, dig up the root area and split into multiple plants.

dividing perennials in late summer
Hosta plants can easily be split in mid to late summer.

Like with splitting any perennial, the size of the root split will determine the size of the perennial. Small splits will create smaller plants, larger splits, larger plants.

Water the roots well and replant into the landscape. Be sure to water every few days after planting for the first 3 to 4 weeks.

In most cases, you will see new growth begin to appear in about 3 to 4 weeks. And by next spring, it will be ready to take off.

Daylilies

Start by cutting back the foliage and all flower stems of daylilies to around an inch above the ground.

splitting daylilies
Daylilies are one of the easiest of all perennials to split and divide.

Split the plant into the desired size, water the roots, and replant. Daylilies are one of the easiest and hardiest of all perennials to transplant.

As with the hosta plant, you will see new growth appear from the base within a few weeks after transplanting.

Avoid Splitting Ornamental Grasses In Mid-Summer

One perennial to avoid splitting during the summer months are ornamental grasses.

They are simply unable to handle the stress and heat of mid-summer dividing.

fall's beauty
Ornamental grasses should never be split in the middle of summer.

Springtime is the best time to split ornamental grasses See : How & When To Divide Ornamental Grasses

Here is to dividing your perennials this summer, and filling your beds with loads of free plants!

Happy Gardening! – Jim and Mary.

As always, feel free to email us at thefarm@owgarden.com with comments or questions. To receive our 3 Home, Garden, Recipe and Simple Life articles each week, sign up below for our free email list. This article may contain affiliate links.

Dividing Perennials In Late Summer – How To Create New Plants For Free!
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