Plants are triggered to flower from a lot of different things. Some are slowed down dramatically by the cold or rain, while others don't care at all. Lots of little factors can throw off the blooming of certain species. So this can all vary form year to year.
Often by the time the Mt. Cuba Center has their Wildflower Celebration plants like Hepatica, Twinleaf, Trout Lily (both white and yellow), Snow Trillium, and Trillium pusillum have all finished flowering. This year, though, these were all flowering, but most of the non Trillium ephemerals hadn't opened as much. Often the forest floor to their woodland gardens are covered by a mixture of Virginia Bluebells, Fernleaf Phacelia, and Woodland Poppy, which all spread almost thuggish in the gardens there.
A few years back all the stars aligned and pretty much every spring ephemeral was in full flower. The Snow Trilliums, Twinleaf, and both Trout Lilies were all bloom in good number along with vast carpets of Phacelia, Bluebells, and Poppies to the point that the forest floor could not be seen. Creeping Phlox, Foam Flower, Bluets, Ragwort, multiple species of Spring Beauty, a variety of trees including Redbud, Witch Hazel, and Dogwoods were all in full bloom as well. And this wasn't just a few patches here and there as it often is; it was everywhere! This was also the year I saw Wild Camassia there, a native bulb no one seems to recall planting and have either died out or been removed from the gardens since. I have an awful picture of them somewhere so I know I'm not crazy but none of the gardeners there seem to recall the species ever having been planted. (It was likely removed because Camassia is more of a midwestern plant).
This year's display wasn't as grand as that golden year. It's important to remember this isn't a flower show where plants are grown and timed in green houses and planted at the moment of perfection. These are plants left to grow in the ground all year so their flowering is largely effected by the weather. I would never say it was a disappointment to go. There are always tons of wildflowers in bloom just not in abundance throughout the gardens. And as always it's worth going for the Trilliums alone.
So here are a few highlights that I enjoyed seeing.
Phacelia bipinnatifida. The Mt. Cuba Center is where I first learned about this plant and I've wanted it ever since. Who knew an aggressive spreading, biannual, that's swarming with pollinators, and turns forest floors into cloudy carpets of purple would be such a tough sell to the nursery industry. No one sells this species except for one awful nursery online that only sells it in bare root form, and the occasional native plant sale. I have to drive all the way to Delaware to a place just down the street from the Mt. Cuba Center to buy this plant and hope and pray that it reseeds itself in my yard. Please someone, just sell the seeds to this plant online.
I'm reasonably sure the Mt. Cuba Center occasionally harvests the plants from the patch to use elsewhere in the garden. I've started seeing them growing in patches along the pond and in other moss rich parts of the garden.
Mertensia virginica. Both the typical blue form that is so common and a very rare red form. Normally these start to open up red and quickly change to blue when they fully open. The flowers stay that way a few days before falling off. With the red form though the flowers never turn blue.
Both fall in comparison to the blue which I've seen dominated the forest floor in years past.
Erythronium americanum. While I don't always see this plant blooming at the Mt. Cuba Center every year, when I do see them I normally see it flowering in large patches. This year though this one plant was the only one I noticed... odd.
Trout Lilies are notorious for not flowering though. They spend too much time spreading by horizontal roots to form new bulbs. Each bulb then works on sending roots deeper in the ground but they only flower after reaching a certain depth, which can take forever. The result is a huge patch of leaves but no flowers every year. I'm told though that planting them in pots or adding stones a few inches under the bulbs will help stress the plant into putting its energy into flowering. I have yet to try this trick out.
Helonias bullata. This is an endangered species I'm happy to see they still have there. On some years they have a dozen or so plants all blooming around the ponds but this year I only noticed this one.
Some nurseries have found out how to germinate this species in captivity and are making it commercially available. I've tried to grow it in my gardens though but found it too finicky to survive here. I suspect it's not drought tolerant at all and requires constant moisture year round which I wasn't able to give them.
They had tons more Trilliums and variations there of growing in their gardens but I wasn't able to photograph it all as I've done on years past.