Question:
Our garden beds were taken over with a plant that grows from a white bulb and has purple bellflowers of a central stem.
Last year, I dug down a foot, pulled out all the bulbs I could find and filtered the soil I put back. But this spring thousands of new shoots are growing from deep tubers, bulb connectors or tiny minibulbs.
Is this a stick-with-it-obsessively-pull-up-every-bulb-you-see-for-the-next-five-years-and-they-may-go-away-maybe-situation? Or should I do as my husband says and just be thankful that there's something I can't kill?
Tess Trethewey, Coquitlam
Answer:
You've got the creeping bellflower (Campanla rapunculoides). It's just what you described - a "stick-with-it-obsessively" gardeners' nightmare.
It's a good-looking plant so you could try learning to love it - but it usually spreads into a dense mat that out-competes everything else.
There's no quick trick or magic potion to remove this.
Weed-killers remove only the upper growth - and those fat, deep-down tubers have lots of reserves that put up more stems.
It's crucial to deadhead the flower spikes so that they never get a chance to seed. But the real key to removing it is to dig up the tuberous roots. It sounds as if you didn't dig deep enough for the big roots. You may need to dig down about 45 centimetres (18 inches).
I'd recommend a Lee Valley Tools drain spade because it has a longer blade than ordinary spades. It's quite heavy, but it's helpful in retrieving many bulbs (such as snowdrops, camas, bluebells) that work their way down to China!
Trying to tackle all the garden beds at once is probably impractical.
You could select one war zone for digging and move your most precious plants somewhere else that's hopefully bellflowerfree. Wash their roots.
Don't move any soil over.
After deep digging, cover that area with black plastic. Then weigh down the plastic with something heavy enough to flatten any up-thrusting shoots and nice-looking enough to be a patio for a container garden. Any remaining mini-tubers should die out in a couple of years. Before reclaiming the bed, put a seven-centimetre (threeinch) mulch on top. This should prevent any old bellflower seeds from germinating.
With the other beds, deadheading the clumps, weeding seedlings and continuing to sieve soil to remove mini-tubers
should hold the situation static until you can begin a deep-digging battle in another conflict zone.
I wish I could help you more, Tess. This is a very difficult plant to eradicate.
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Question:
Many of my big sword ferns didn't die this winter. Should they still be cut back to let the new fronds grow?
Norma Becker, Tsawwassen
Answer:
It's still best to prune old fronds to ground level each year so that new growth has space to flourish.
This is because old growth will get shabby, and then you'll likely want to freshen up the plants.
But at that point, cutting back will be a problem because new growth will have joined old growth, and you'll need to cut the old growth selectively. This is a long, painstaking process.
News flash: The Bradner Daffodil Show will be held April 13, 14 and 15, from 10 a.m. to 5 p.m., in Bradner Community Hall, 5305 Bradner Rd., Abbotsford. It will include a plant sale. Admission is $2. For more, call 604-856-8441.
Anne Marrison is happy to answer garden questions. Send them to her via [email protected].
