One FWG volunteer is reclaiming a wet meadow from invasive species and planting it with sedges, Swamp Milkweed, Meadowsweet, and other local wetland species. 

by Sandy Garland, photos and strategy by Catherine Shearer

Bumble bee visiting Comfrey flowers. Photo by Catherine Shearer.

Catherine Shearer, who received a volunteer recognition award from the FWG Management Committee this year (see The FWG loves its volunteers) is waging a war against the invasive species in what we call “the gully” at the FWG. Although this area is important – as one of our few damp areas and highly visible from Prince of Wales Drive – it was neglected for many years, as we just didn’t have enough volunteers to tackle it.

In 2004, when we received a grant to create a Monarch waystation, the gully was chosen as a prime spot for Swamp Milkweeds (Asclepias incarnata). However, lack of volunteers meant that attention was focused elsewhere and the gully slowly filled with our nemesis, Dog-strangling Vine (DSV; Vincetoxicum rossicum). Later, Common Comfrey (Symphytum officinale), which had grown docilely along our entrance road, suddenly invaded the New Woodlot and cropped up everywhere.

The good news: comfrey drives out DSV and is also very attractive to bees, especially bumble bees. The bad news: it spreads aggressively, has long roots, drives out everything else, and has the unfortunate habit of falling over and turning black after flowering.

But, slowly but surely, Catherine is digging out invasives and planting some of our many, many local native wetland species.  Her strategy:

Sedges, grow from seed and planted on a rainy Tuesday afternoon in 2017, are flourishing in the damp bottom of the gully. Photo by Catherine Shearer.

Week 1

  • clear comfrey and DSV in one section
  • turn soil to find/remove the deeper DSV root nodes
  • leave for a week
Week 2
  • clear and turnover a new section‎
  • in the section from week 1, remove the comfrey/DSV‎ that crops up
  • put in plants appropriate for sun / soil / moisture conditions. Each plant should be in a little depression to keep water from running away when watered
  • water newly planted plants – about a cup per plant – then do a second round of watering after 10 minutes
  • toss grass seed freely. Preference is for native grasses but cost is prohibitive.
  • if there is no rain in the next 2 days, water plants. Same “double watering” as before.
Week 3
  • clear and turn a new section
  • in week 2’s section – weed, plant, water
  • in week 1’s section‎ – weed, assess how well it is doing on its own, water if no recent rain and none in short-term forecast
Ongoing
  • keep adding new sections‎
  • prioritize which sections to focus on, e.g., ones that are predominantly DSV before ones that are predominantly comfrey
    OR
  • do ones with unique conditions like wet marshy vs sunny dry
  • in all replanted sections, monitor natural rainfall and be prepared to water twice a week if there is a drought

How to remove comfrey and DSV

Any digging or pulling should be done in the days following a soaking rain (either downpour or all day light rain), as this loosens the clay soil enough to release roots.

Comfrey (large, flowering) – ‎dig down at 45° angle at several places around plant, then one more strike deeper and pry out the huge tap root. The older the plant, the bigger the taproot – some are 4+” thick! Discard into a pile – they compost quickly. Little plants will generate from that taproot but you can keep an eye on the pile and stop them when you see them.

Comfrey (smaller) – one shovel and pry. Discard to a pile. These smaller taproots are less likely to generate sprouts.

DSV – single plants can be pulled and you should get a star shaped root system with it. For clusters of DSV, there will be a deeper root “node” that you need to get out or the plant will keep regenerating.

Prairie Cinquefoil (Potentilla arguta), growing on the sunny north slope of the gully. Photo by Catherine Shearer.

This year, we are very lucky to have help from 3 Algonquin horticulture students – Joey, Ahmed, and Thomas – who work with Catherine on Mondays and attend classes the rest of the week. They are a tremendous help when it comes to digging and scything and are opening up more space for Boneset (Eupatorium perfoliatum), more Swamp Milkweed for Monarchs, more sedges for skippers.

Last fall, we also had help from a crew of Carleton U students who spent a whole morning digging comfrey out of an area where we then planted White Meadowsweet (Spiraea alba) and Buttonbush (Cephalanthus occidentalis).

Thanks also to the people who donated plants for this part of the garden, notably Lyse for the magnificent Swamp Milkweeds, Lynn for mature meadowsweet shrubs, Renate for yarrow plants, and Trish Murphy for Big Bluestem (see photo).

Big Bluestem (Andropogon gerardii), grown from a single plant donated by Trish Murphy of Beaux Arbres.

When you visit, watch for large clumps of Wild Bergamot (Monarda fistulosa) on the north slope of the gully, along with Black-eyed Susans (Rudbeckia hirta) and Prairie Cinquefoil. Lower down, you might see tall-growing Big Bluestem and, on the south, shady slope, Sensitive Fern (Onoclea sensibilis) and Spotted Jewelweed (Impatiens capensis). Seeing the changes with the seasons, but also the transformation that volunteers are achieving in this part of our garden is a delight.


The rewards of growing native plants

July 4 – Meadowsweet planted last year is just blooming and already the bees have discovered it. A bumble bee is just visible on the right side of this flower cluster.

August 24 – A month and a half after we wrote this blog post, the rewards have multiplied many-fold. Every time we visit the area, we see Monarch butterflies flying back and forth from one nectar plant to another and laying eggs on Swamp Milkweeds and some Common Milkweeds.

Both of us (Catherine and Sandy) are raising Monarch caterpillars at home (to help the population recover by ensuring high survival rates). One week, we released over 20 adult butterflies in the gully, and they are now producing the generation that will fly to Mexico this fall.

The Meadowsweet has finished blooming, but asters are starting, Boneset is in full bloom, and the milkweeds just keep flowering and flowering. Lots of bees, wasps, and other pollinators are having a field day.