Phacelia has been a genus I've become more and more interested in with each passing year. The issue is most members of the genus I'd like to grow are not commercially available as I'd like to buy them. Most are annuals or biannuals making seeds ideal, so why is it that all the biannuals are sold already germinated and flowering as though they were annuals. The stress of getting planted out of a pot makes them suddenly invest in making roots when they should be pumping out seeds to no end. As a filler though I've been coming to like Waterleaf more and more.
They're generally easy to grow from seed in places lacking competition. They like moist soil and tolerate average soil with a little watering. It's harder to get them to self seed in dry places but it can be done. Shade to Part Shade is ideal, too much sun you'll have to water them almost daily. Rabbits, and one imagines deer too, like to eat them but in a diverse landscape their tastes venture from plant to plant.
Virginia Waterleaf, Hydrophyllum virginianum, was the first species I've grown. Each plant is only a couple of stems making them somewhat thin and scraggly. They've been described as aggressive spreading which I agree with but only from their constant habit of self seeding all in one place. Droves of new plants come up in one huge clump from where the flower head laid. They're supposed to spread underground too by an expanding rhizome but I've found seed spreading to be far more aggressive.
The rabbits did eat a few of my plants, but they only nibbled the leaves off, leaving the flowers in tact. New leaves grew back in a few weeks. This didn't interrupt flowering at all but they did look funny as just some stems with flowers on them. Bumblebees mostly go to them but there's also an Andrenid bee that's a specialized pollinator of Waterleaf plants, Andrena geranii. Though to be fair you'll also find that bee working Roses, Anemone, Raspberries, Geranium, Campanula and the occasional Violet.
By comparison Great Waterleaf, Hydrophyllum appendiculatum, is a robust flowering specimen that's full of foliage. The stems branch out making a single plant fuller looking almost like a small shrub.
This plant also goes by the name Broad-leaf Waterleaf becuase the leaves
superficially resemble those of an oak or maple tree. However they're
actually much much smaller than the leaves of any tree. An exception to this might be the early rosette of leaves that forms in late winter, which is absolutely spotted with little water stains members of this genus get their name from. New leaves formed in the spring and summer are lacking this trait and completely cover up the initial rosette.
I hadn't realized I'd already planted this species from a previous year, and some Phacelia spp. also have the waterleaf stains on early leaves. It's so easy to forget what's growing when you just throw out hand fulls of seeds mixed with dirt. So I already had a plant of this growing when I ordered more seeds to plant this spring.
This is what the two year specimen looks like having expanded from the rosette to flower. Most of the seedlings I tossed around didn't produce much more than just a leaf, however one of these first year plants has gotten a little bold and is flowering at only 6" tall.
My one regret with this species is not having planted it someplace where it would have more room. There's a few Indian Pinks, Stone crop, a patch of yellow Trilliums, Hepatica, and a Bleeding Heart growing there somewhere. And it's just shy of being as tall as the Rhododendron growing behind it. This is the perfect little perennial to put right up against a tree.
Great Waterleaf, along with having nicer flowers, also blooms longer than Virginia Waterleaf. Neither are a huge hit with pollinators but watch a plant long enough and bumblebees always seem to eventually show up. I'm not growing it in as grand a number to get honeybee attention but that should change in a few years.