Garden: The Perrenial Divide
The following is a regular column that addresses basic issues facing the ever-inquisitive back- and front-yard toiler, proffered by someone who knows best; one of the fertile master gardeners from the Berkshire Botanical Garden in Stockbridge. This week, Brian Cruey explains the importance of breaking up your perennials, at least once every few years, all for their own good.
Let’s face it—Labor Day was kind of a bust in the weather department this year. Rainy and muggy, it took all my will power not to just park myself on the couch and start a Breaking Bad marathon that would take me through to the other side of summer. Instead, I rolled up my sleeves and turned Labor Day weekend into actual days of labor. Particularly, I spent a lot of time dividing and moving my perennials.
Doing this to your plants has a lot of benefits. For one, it’s good for the health of the plant. Depending on the type, perennials should be divided anywhere from every other to every four years. Often, those that don’t get this treatment routinely won’t flower as profusely, or they’ll start to have bare spots in the centers and start looking like a doughnut. Some perennials will also start overtaking other plants by growing too large for their designated spot. All of these things can end up making your garden look tired and monochromatic. Not only is dividing necessary to keep your garden healthy and attractive–-it’s also essential in helping your garden grow in size.
For example; this weekend I seperated a lot of my hosta lilies. (Hostas can be a real bear to get out of the ground if they’re large–-be ready to sweat and curse.) One in particular was getting so large that it was encroaching on neighboring plants and crowding them out. I dug up the plant and split it into five, yes FIVE, smaller plants. I had about four hostas that were similar in size, and after dividing those as well, had almost 20 hosta plants and a desperate need for a beer. This is how you garden grows over time. You can plant the divisions in new beds or extend existing ones. It can also be fun to take split up plants and trade them with friends or family. This adds variety to your garden and is a very cost-efficient way to acquire new cultivars. OR (wait for it—here comes the plug) you can donate some of your divided plant material to the Berkshire Botanical Harvest Festival Plant Sale, which will happen this year on October 5th and 6th, with donations already being accepted.
No matter what you decide to do with your plants, routine division is an important part of your garden’s life cycle. I find that fall is the perfect time of year for dividing and planting new plants. Temperatures are cooler, days are shorter, rain is more abundant, and your plants are all getting ready to put themselves to bed for the winter anyway. Though necessary, plant division is a shock to a plant, so you want to be prepared to get your new plants into either the ground or a pot with soil as quickly as possible. For most plants, division can be done with spades of garden forks (put two garden forks in together and then pry the plant material apart). However, for things with much denser root systems, like ornamental grasses or those hostas I dug up, you need to be more aggressive. Use an axe or, my preferred method, an electric Saw Zaw. Of course, use extreme caution.
Exposing the plant’s roots by taking it out of the ground causes dehydration, so be sure to give your newly planted divisions plenty of water. Also, for things like day lilies, irises, and ornamental grasses, cut back the leaves by about a third. This reduces the amount of foliage that the plant is working to maintain, but still leaves plenty for energy production to get that new plant on its way.