By Patrick Greenwald
Some might be confused when they find out that I recently planted Collinsia verna, spring blue-eyed Mary, seeds along the Dogwood Path at Mt. Cuba Center. Summer is not usually the time you typically think of sowing seeds outdoors, but for this winter annual, late–spring to early–summer is the perfect time to sow fresh seeds in preparation for fall germination.
The seeds of many early spring–blooming native plants, like Collinsia verna, naturally drop to the forest floor in late spring, lying dormant in the soil until temperatures cool in autumn. After seeds falls off the parent plant, the plant quickly dies and disappears from the landscape by summer until the next generation of seeds begin to sprout in autumn. Once the seeds drop off the parent plant in late spring, they go through a process of after-ripening, in which seeds continue to develop in warm summer temperatures and appropriate humidity under forest leaf litter. This is when seeds begin the process of breaking dormancy; sprouting the moment temperatures are ideal.*
Collinsia verna is native from the Midwest to the northeastern United States, with a natural range stretching from Oklahoma up to New York state. It is happiest where there is sufficient soil moisture during its growing season. The plants themselves do not take up much room, only standing up to 15” tall. It can be found in rich, bottomland deciduous forests, in places where it annually carpets the forest floor. I have seen photos from a park near where I grew up, where the forest floor was covered in adorable blue and white flowers.
When planting spring ephemeral seed in summer, it is crucial to sow fresh seed. Improperly stored seed for longer periods of time can adversely affect germination percentages. For a few years now in my home garden, I have successfully planted spring blue-eyed Mary in summer in a woodland garden setting. One of the earlier wildflowers to bloom in my garden, they now annually seed themselves back into the landscape, popping up in random places. To ensure future years of enjoyment, make sure to allow the plants to mature and scatter their seeds before removing any dead foliage from the garden. It is always so exciting to see the tiny seedlings sprout in November.
If all goes well, I look forward to seeing Collinsia verna seedlings develop here at Mt. Cuba this coming autumn, when it can join the glorious display of spring-blooming native wildflowers here in the gardens. If you are fortunate enough to find seeds for this amazing native of the eastern deciduous forest, try it out; you will not be disappointed.
*Germination ecology of Collinsia verna, a winter annual of rich deciduous woodlands. Jerry M. Baskin and Carol C. Baskin. Bulletin of the Torrey Botanical Club , Jul. – Sep., 1983, Vol. 110, No. 3 (Jul. – Sep., 1983), pp. 311-315