Digging up perennials is a rather simple task, although it does require a bit of “muscle.”
September is a great time to do some planning in the garden, to rearrange plants and garden structures, perhaps even to completely redo a flower border. Many of these fall endeavours involve digging up and moving perennials, and in doing so we often take the extra step and divide them both to rejuvenate and to obtain additional plants to use elsewhere in the garden. There are some experts who recommend autumn as the best time to move perennials since the soil is warm – and will stay that way for several weeks – so the new divisions are able to set their roots down and get firmly established before freeze-up.
Most perennials can be dug up in the fall except for iris, which should be moved and divided right after they bloom or a season of bloom will be lost. Another possible exception is hostas, although I know people who have successfully moved hostas in the fall. My personal experience has been less successful so I choose now to leave the digging up and dividing of hostas until spring.
Digging up perennials is a rather simple task, although it does require a bit of “muscle.” Choose a sharp spade and dig around the clump being sure to stay well enough away from the plant so the shovel does not damage the roots. Ease the clump out of the ground leaving the soil intact around the roots. If there has been dry weather before doing this task, it might be a good idea to water the perennials the day before so that the soil will stay in a clump and not crumble away.
If the clump is quite large it is usually best to divide it so as to rejuvenate the plant, and what better way to get some more perennials for the garden! The best way to divide the clump – unless there appears to be a natural division already existing whereby the clump can be eased apart – is to simply slice the clump in half with a sharp spade. The halves can be further divided in the same method if they are large enough.
Plant the clumps to the same depth as they were originally growing and amend the soil used to fill the holes if you feel it is required, although most gardeners annually amend the soil in their perennial borders with compost so the soil may be just fine. Fill the space
around the clump with soil and water thoroughly. The tops can be left on if they are still green and in good condition, to assist the plant in recovery, although very tall stems on plants such as delphiniums, ligularia, golden glow, filapendula, and monkshood to name a few should be cut back to a height of 30 to 45 cm.
Clumps of lily bulbs also can be dug up and divided in the fall. There will be some large bulbs and many, many small ones so the larger ones can be replanted in clumps of a dozen or so, placing them about eight cm apart in the hole. A decision will have to be made about how small the bulbs have to be before they are discarded, or you may end up with far more clumps of lilies than you want. Perhaps the excess ones can be given to a friend or donated to a garden club that is having a fall plant sale. Some gardeners have a “storage garden,” a spot somewhere in the back of the garden where excess and ailing plants are stored until the gardener decides where to put them or whether they are worth saving.
When deciding where to plant your new clumps of perennials, you may want to consider how the plants have performed in their present locations and judge accordingly. If a particular plant seems happy in its present spot, choose one with similar light conditions for any additional clumps. If a certain plant has struggled, however, you may want to move it to a spot with different light levels that better suit the plant. Finally, be sure to place sturdy labels which won’t fade and disappear by spring beside each perennial so that you know where things are when you start gardening in the spring!
– Albert Parsons writes from Minnedosa, Manitoba