Little alpines will soon spread
Large plants can be divided with a spade or two garden forks held back-to-back
All photography TI Media
Red persicaria is an attractive plant
Planting bistort divisions and alpines to help keep rockery weeds at bay
Two jobs with one plant!
Ruth beats invasive rockery weeds with a split perennial
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OMPLETING two jobs in the time you’ve allocated for one is one of the most satisfying things about gardening. Our problematic rockery, overrun with weeds and rampant campanula, needs a complete overhaul and is one of the major projects earmarked for 2020. We also have a large clump of red bistort (Persicaria amplexicaulis) that is stunning when in full flower, but which has grown tatty and uncontained. In winter it resembles a tangled brown mat, but in summer it transforms into a mass of emerald leaves topped with attractive pink flower spikes that turn a glorious red as they ripen. The bistort’s spreading habit means
Step by step
it is excellent for suppressing weeds – and unregulated campanula! – so I decided to split it and plant the divisions in other areas of rockery. Although the plant is large and tangled, it was easy to remove a few plantlets as several of its many offshoots were lightly rooted and could be carefully dug from the soil without damage to their roots. I replanted these offshoots in an area of rockery cleared of weeds and campanula, and added a couple of little alpines that will hopefully spread and similarly help keep weeds and other unwanted plants at bay. Two jobs in one morning – and just in time for a well-deserved mug of coffee!
Tips for dividing A healthy start for new plants Perennials can be divided in winter and early spring as long as the soil isn’t waterlogged or frozen. Lift the parent plant, keeping as much soil around its roots as possible, then cut into divisions using a spade or two garden forks held back-to-back and levered apart. Make sure each new plant has healthy roots and top growth before you plant it, making sure it Protect roots while goes in the ground transplanting at the same depth as the parent plant. Water and keep weed-free. If there is a delay between dividing and planting, wrap the roots in damp paper and store somewhere cool for up to 24 hours.
Replanting perennial divisions to beat weeds
Clear the planting area of stones, debris, unwanted plants and their roots. Break up compacted soil.
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This soil is thin and undernourished, so I forked in lots of rich homemade compost and leafmould.
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Keep new plants watered and weed-free while they establish
I checked the roots to make sure they were healthy, and untangled those that needed it.
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8 AMATEUR GARDENING 1 FEBRUARY 2020
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When planting divisions, make sure Finally, water your new plantings they go in the ground at the same well to hydrate the roots and depth as they were before. Firm them in. settle the soil.
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