You posted an article today about cutting back Shasta daisies etc. when they’ve finished blooming. Can I do the same with Virginia waterleaf after it’s finished flowering? I realize it’s a native plant and in the wild it would never get cut back, but I have an enormous clump (which the bees love when it flowers) and it’s pretty much flattened at the moment – even with the rain we’ve had today. I think it’s just too big, whereas it would never get that large in the wild. I don’t do anything to it (water or fertilize), but every year it just gets bigger and then after it flowers, it just flops on the ground.
Thank you for contacting Toronto Master Gardeners.
The Virginia waterleaf (also known by its botanical name, Hydrophyllum virginianum) is native to Eastern North America and does prefer moist, well-drained soils in a light shady spot. This plant can grow aggressively when it is happy with its conditions, so I can understand your desire to cut it back. It spreads by both seed and rhizomes (underground stems). Virginia waterleaf blooms in May/June, so pruning it back now will not result in a second flowering this year (as it may do for some other herbaceous perennials); however, it may help prevent further spread by seed, so you should be fine to cut it back now.
Happy gardening!