How to divide Spiderworts – and lots of other perennials

Spiderworts in their May and July glory.

by Susan Harris

The violet flowers were no more, the foliage was looking ratty, and it was time to prune these Spiderworts (Tradescantia virginiana) and prune ’em hard.    With any luck, they’ll grow new foliage and look good again in a couple of weeks or so.   Anyway, it beats letting them look ratty for the rest of the season.

But while they have their new haircuts it’s a great time to also divide the two larger clumps in order to cover some bare ground in my perennial border and simply produce a larger, fuller mass of this perennial favorite of mine.

Newly pruned

These clumps are big enough to divide into four pieces each.

How to Divide Spiderworts, Hostas, Tall Sedums, Liriope, etc.

1. Dig up completely, as in the picture above.

2. Slice through the root mass with a knife to produce good-sized chunks. My favorite perennial-dividing knives are steak knives from the dollar store – 4 for a dollar.  They gradually get dull, so I have to buy another 4-pack every few years but it’s still the cheapest tool in the shed.  All the perennials listed above are easy to cut through but none easier than this Spiderwort, which I’d never divided before. After the first slice I declared aloud: “Cuts like buttah” (with apologies to a famous Saturday Night Live sketch).

3. Place the new divisions in the garden where you want them, then step away from those plants!  Literally – step back so you can check to make sure that’s where you want them. (This step is especially important for plants that are harder to replant – like trees and shrubs. unfortunately, it’s a step I’ve sometimes ignored it in my haste.)

4. Plant, and mulch around them.

5. Water well. In this heat, I’ll keep watering daily for a few days, then keep an eye on them for the rest of the season. Mid-summer is a terrible time to move or divide anything, but I think these guys will survive – thanks to good watering and the severe haircut they’d already received. That’ll keep them from losing lots of moisture through the leaves.

Divisions placed where I want them, before planting.

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