Dividing Perennials

A client asked me about this today, and I thought what a great blogging subject. Because yes, in zone 4 & 5, now is the time to start thinking about what you want to divide. First, how do you know if you should divide? The obvious is of course, the plant that is a lot larger than you ever wanted it to be. The more subtle tell tale is to look at the inside center of the plant, is it still vigerous with strong growth?
Most experts will tell you fall really is the BEST time to divide, but a proper spring division should lend good results.
For a rule of thumb, let daffodils tell you when to transplant. About a week after they go to full bloom is when you should look at the perennials you want to transplant, when you see the first signs of growth, low to the ground, it is time.
You will need: garden shovel, spade, compost, bucket of luke warm water.
To start designate where the drip line is on the plant. That is the circle the roots tend to lie within. Mark it with a a shovel all the way around, then dig down. 18" should be good for most mid size plants, 12" for small low to the ground perennials.
Sedum, dianthus, and many others can be easily pulled apart or loosened into sections and pulled with your spade. Aim for clumps that are 20-25% of the plant. Example, one overgrown plant, should yield 4-5 sections to replant. If you find division difficult, setting the roots of the plant into the bucket of water and gently working the roots should help ease them apart.
When it comes to plants like day lilys and ornamental grasses, I have to be honest. I normally end up using an edging shovel and just chopping off sections. These plants are incredibly hardy, and gentle separation of those roots is usually out of the question.
Where ever you are planning to replant, make sure you dig the hole twice as deep as the length of the roots, and 2-3 times as wide. loosen the soil at the bottom of the hole so new root growth can get through. Now, add compost to fill half the depth of the hole. Plant your plant, add a good topsoil the rest of the way. Make sure the root ball is not buried, keep your plant base at the top of the new bed, just as it was before you dug the original up. Add 2-3" mulch, water well, water daily, and you are done! Let me know how it goes. And don't forget, if you have a question you can always contact us directly though our web page at www.paradisegrounds.com
Julia