How you run your garden depends a lot on the state of it. If your plants have plenty of room to breathe, look happy and healthy and are flowering profusely, you can treat them gently, singing sweet serenades to them and pandering to their every need. If, however, your garden has become rowdy and overgrown and is simply not behaving, you need to put your foot down and slam down an iron fist. You need to cut out the weak links, separate the men and the boys, 3 words: Divide and Conquer. Signs that you need to get in touch with your inner dictator are:
· Plants are outgrowing their space
· Plants are starting to look “leggy” or ratty
· Plants have become donut-shaped with bare holes in the center of the clump (happens mostly with grasses, salvias and some other spreaders)
While you want to put those plants in their place, you also want them to be a part of better, improved garden, not kill them. When to divide depends a lot on the plant but there are a couple rules of thumb to follow to ensure that they will tow the line:
1. Do not divide them in the hot part of the summer (Late June-August). The reason is that plants are already under stress at that time due to the heat and lack of water and you decrease the chance of survival by inducing more stress. If necessary, some tough plants (day lilies, hostas, etc) can be divided at this time but you need to be extra diligent about watering so do this at your own risk.
2. Divide them only when actively growing. If divided in fall, make sure they have enough time left in the season to get some root system established, 3-4 weeks minimum.
You need to be strategic when it comes to taking back your garden. The spring and early to mid-fall are the best times to divide. Much of what you read says that plants that bloom early (spring to mid-June) are best divided in fall and those that bloom later (late-June to fall) are best divided in spring. The reasoning behind this is that it takes energy to produce blooms and if you don’t give plants time to recover after dividing, they may not bloom or the bloom display may be diminished. That said, many gardeners, including myself, break this rule and the plants themselves will more than likely be fine and bloom the next year. The seed head on grasses can be considered their “flower” so they are best divided in spring.
The technique for dividing is fairly simple and many tutorials can be found online. Begin digging at the plant’s dripline which, for perennials, is usually from 3-6” out from plant’s base but could be more. Generally, the bigger the plant, the bigger the root ball you need to dig up. You want to make sure that you keep most of the plant’s root system intact to help it get reestablished. You want to lull the plant into a false sense of security that everything will be OK, but once you get the plant and root ball out of the ground, you are going to hack it into pieces. If the plant is large this is best done with a square point shovel so the cuts are straight and even. Some smaller plants can be divided with a trowel, soil knife or even by hand. When dividing, try to keep the new sections as equal in size as possible, otherwise the little ones will be complaining all the time about how they didn’t get enough roots and the big ones will be beating up the little ones. The exception to this is if you are keeping one and giving the excess plants away. Maybe cut in half or a third, keep the big one and give smaller ones away. As a general rule, the maximum number you want to divide a plant up is into thirds or fourths (plants with a large root ball, like Miscanthus, could be divided up more). Next, arrange the divided plants on the ground how you want them to look once planted. Dig a hole about twice the width of the root ball (this loosens up the ground around the new plant) and just deep enough so the base of the plant sits level with the ground (a little too high out of the ground is better than too deep). Fill in with soil around the root ball and make sure they are watered regularly until established. If divided in the spring, they may need a little more water than usual during the heat of the summer that first year (keep an eye on them for signs of drought stress like wilted flowers or leaves). You can now put your inner despot back deep down inside and treat the plants with the loving tenderness that is your true disposition…yeah, right…
