Dividing Perennials

Dividing Perennials

Part of Ep. 402 Planting Beauty for Your Yard and Garden

Divide your perennials in the spring for best results. Master Gardener Ann Munson demonstrates how to successfully separate the plants.

Premiere date: May 31, 1996

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
This is the perfect kind of day to be dividing perennials. It's cloudy and overcast, so you won't stress out the plants. Joining me is master gardener, Ann Munson. You said, in general, you prefer spring to divide perennials. Spring is an excellent time to divide perennials. The weather's cool and plants are growing vigorously. If you try it in the fall sometimes your plants don't make it through the winter. You've already started some of these. You've got this massive ball of aster, here. And you said that this shows us a very good reason of why we should divide perennials.

Ann:
There are generally three reasons to divide perennials: control the size, rejuvenate the plant and make divisions to give away to friends or to plant in your garden in other places.

Shelley:
What is this showing us?

Ann:
This plant has died out in the center. So, by dividing it, you'll be rejuvenating it. The center has died out, but it's growing towards the outside where there's fresh soil.

Shelley:
Now, I think of an aster as having a tough, fibrous root system. What else would... Phlox would also be like that. So, day lilies, over here, are more tuberous?

Ann:
Right. Some tubers are easier to pull apart--

Shelley:
I think of hostas. This particular day lily, I dug up previously and you can see that these roots are very, very dense and grown together. You had a real massive root ball. Do you just cut into it?

Ann:
I dug out about three inches from the center of the outside of the plant and got as big a root ball as I could. We've hosed down a piece so we can get a closer look at what the roots are actually doing, which is a great idea for beginners so you can see what's happening below the soil. You can see how dense those tubers' roots are. This would be a very tough one to pull apart. You're going to have to use a very sharp cutting tool. I used the lawn edger. Or, a knife would work. Don't worry about hurting the roots of the day lily they're a very tough plant.

Shelley:
Now, you just sliced the side? So, you just kind of cut right through it?

Ann:
Take your edger and slice right through it. We're being pretty tough.

Shelley:
Would you plant it, then, at this size?

Ann:
I might divide this one more time. This particular clump of day lilies I could make eight divisions. I'll put one of the divisions right back in the hole that I dug it out of. The other ones, I'll dig other holes and give away to friends or share with people.

Shelley:
What about the aster? Let's see what you've been doing.

Ann:
That one is harder to see what's happening, there. I would take my lawn edger and...

Shelley:
This is for edging lawns not really for dividing perennials?

Ann:
It's a great tool because it's very sharp and this is a very tough, fibrous root system.

Shelley:
You dig right down through it.

Ann:
Don't worry, you're not going to hurt the plant.

Shelley:
So, very brutal is what I'm seeing here, then?

Ann:
Yeah, and then just take your division...

Shelley:
Now, that's quite a chunk.

Ann:
Just put it back in the soil, back in the hole.

Shelley:
Is that a good size?

Ann:
Keep it about this size.

Shelley:
Now, I've got a lot to do in my yard. I may not get to 'em all today. Can I leave 'em sitting outside?

Ann:
If it's a day like this, you could. If it was sunny, cover the root system up so they don't get too hot. Make sure they're moist until I get 'em back in the ground.

Shelley:
Thanks, Ann. Remember, like any other new plant make sure that they all get an inch of water a week throughout the entire growing season.

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