MY 2 CENTS IS THAT EUPHORBIA PALUSTRIS is the best euphorbia, or at least for cold-zone gardens that cannot grow the really best ones of all (those Zone 8 types like E. rigida, for example, or handsome, tall characias subspecies wulfenii, a Zone 7-hardy beauty). Now that those words are out of my mouth I am thinking how much I love every Euphorbia, so maybe I am a big fat liar by saying one is best. Oh, dear. Want to know why I wrote that first sentence anyhow, and what I love about this plant?
E. palustris, as its species name reveals, is a marsh-type plant, so wet and heavy soils are no problem for it (though it doesn’t seem to require them). Most spurges are finicky about such conditions. Not this one. It gets to between 2 and 3 feet tall and at least as wide.
I grow seven or eight other Euphorbias, including the basic polychroma, its newer, red-foliage variant called ‘Bonfire,’ and the fiery-colored one called E. griffithii ‘Dixter.’ In California, mail-order Digging Dog Nursery has a good list of spurges, but not palustris. I swore I got my most recent generation of plants at Forestfarm, but I don’t see it in their current list. Hmmm….how about Annie’s Annuals?
The hardest thing about growing spurges is cutting them back, meaning forcing yourself to do it even when they still look OK. I have to confess I don’t like to cut back E. palustris (I do with the polychromas, after their bloom starts to fade, and they push up a new mound of freshness). I divide this lovely taller species every few years to keep the clumps vigorous, and cut it back in fall during garden cleanup, but that’s about it. Remember: the milky sap of Euphorbia (from poinsettias to the cactus-lookalike houseplants types to these garden plants) can cause skin irritation in some people. Keep your hands away from your face after working with them, and wear gloves.
Oh, and do you have a favorite Euphorbia? I almost forgot to ask.