It seems that, along with deadheading, dividing perennials is one of those tasks that prove intimidating for many gardeners.
Division simply means digging up the plant, splitting it into two or more smaller portions and then returning those sections to the garden (or giving them away).
Although generally low-maintenance, most perennials will eventually need to be divided after a few years. You can tell that a plant needs division when:
There is a “hole” in the center of the plant, where nothing is growing
Flowers are smaller than the year before
The plant has fewer flowers than the year before
The plant has become too large for its home.
You can divide a plant at any time but it will be least traumatic to the plant in fall and spring (I prefer fall). The weather, for one, is cooler – resulting in less transplant shock when the plant is returned to the garden. Stress is also reduced at this time because the plant is winding down for the season and not busy producing new foliage or flowers. All the plant has to do is take root for the winter so that it will be ready to go come next season.
Fall is also a great time to “take stock” of what worked and what didn’t over the last season, so dividing and spreading around your perennials can be an effective means of making some needed improvements in your garden.
So, how do you divide?
Here’s how, using nepeta as an example.
Nepeta is one of my favorite perennials. It is easy to grow, deer-resistant, and if given a good “haircut” after blooming is finished, will re-bloom up to 2-3 times in one growing season. I noticed this summer (the 3rd year that it’s been in my garden) that there was that distinctive “hole” in the center of the plant. Time to divide.
The first thing I did was cut the entire plant down, which I would be doing at this time of year anyway as I prepare the garden for winter. It also makes the base of the plant easier to see and dig up.
Next I smoothed down the roots and decided how many divisions I wanted to take. The root ball was relatively small so I decided on two divisions. How you divide is up to you (and the density of the root ball). I probably could have used my hands but chose my trusty folding saw instead (do you have one of these? It’s one of my very favorite gardening tools).
I cut the plant into two equal portions and returned one to its original home. The other I planted in a bare spot around the side of my house.
As with all new transplants, regular watering is important – even in the fall.
That’s it! While it doesn’t look like much now, next year this plant will have renewed vigor, produce more flowers and look less straggly. And what a great way to get “free” plants – right from your own garden!!
Not all plants respond well to dividing. Books and the web are great resources for determining your plants’ needs, as well as offering more information on how to divide. And I’m always happy to answer your gardening questions here.
Should be a great weekend in our area to get outdoors – happy gardening!