Like a lot of biennial species, Common Evening Primrose has a lifecycle affinity for disturbance and is prolific in both flowering and seeding.
They are quick to make themselves at home in physically disturbed soil and on gravely roadsides, where their taproot will both anchor them and allow them to reach down for moisture.
In rich garden soil those taproots can become quite robust, enough that they can be grown as a native root crop if you harvest them at the end of their first growing season. Their seeds and young seed pods are also edible.
Their first-year foliage is a ground-hugging rosette that can come in a range of sizes. In the second year they reach upwards into a tall, narrow stalk that, in a garden or meadow setting can either be a single stem all the way up or a sturdy, multi-branched bush depending on how windy or crowded the space is and how much nibbling they may receive from deer or other critters.
As a true biennial, these will spend all of their energy maturing their, often, 1000s of oil rich seeds and then fade. This doesn’t mark the end of their aesthetic presence in the garden though. Their stems and seed pods are very sturdy and will hold up well into the winter, often still standing tall the following spring.
I generally see these thriving in hot, sunny locations, where they seem to be entirely unbothered by dry spells, but some of the pictures today are of a plant that was shaded from about 2pm onward and did just fine.
Their size is mostly defined by how much energy they are able to gather in their first year, but don’t be surprised to see them extend to over 6’ in height if they are particularly pleased with their setting.
An early succession species, these fit well into newly planted spaces and will eventually fade away as the ecosystem fills in and there is less exposed soil and fewer open spaces for them to grow their large, first year, ground hugging rosettes.
Some other species that can fill in quickly to start repairing an ecosystem after disturbance include Nodding and Crowned Beggarticks, Strawberry-Blite, Fireweed, Canada and Virginia Wild Rye, Lance-leaved Coreopsis, Annual and Daisy Fleabane, Pennsylvania Smartweed, Black-Eyed-Susan and Blue, Hoary and White Vervain.