The Amazing Life-sustaining Violet
By Kaila Pennock and Nicole Zehr
Spring is almost here, and an underappreciated ecological powerhouse is getting ready to bloom. Violets have intricate and unique relationships with wildlife and have the potential to help transform lawns and empty spaces into flourishing native habitats. We’ll explain how you can help encourage this transformation with little cost and effort at the end of this article!
Native Virginia violets grow in a wide range of habitats. They are an important part of their ecosystems and help support biodiversity. Violets provide food for spring pollinators and act as larval hosts for many different varieties of butterfly.
They have a unique life cycle involving two kinds of flowers. There are the familiar open showy flowers in the spring that are pollinated by insects. The pale and petalless closed flowers in the fall are hidden at the base of the plant and self-pollinate. The closed flowers produce most of the violet’s seeds and are spread by ants.
The open flowers attract various pollinators, particularly native bees who are docile and rarely sting. They keep to themselves as they do not have a hive or queen to defend. They seek out sunny bare patches to dig their burrows. Individuals often nest in close proximity to one another, forming communal aggregations which are much like bee apartments. There is a bee that gathers pollen exclusively from native violets, the violet miner bee, Andrena violae. This specialist aligns its life cycle to be active while violets are blooming, especially the common blue violet, Viola sororia.
Violets, like many woodland flowers, have an age-old relationship with ants known as myrmecochory. Ants, mainly those from the Aphaenogaster genus, do the majority of seed dispersal for violets. They collect and consume the elaisome, the fleshy nutritious outer part of the seed. The rest of the seed goes into their refuse tunnels which provides a nutrient-rich and protected environment for germination.
Violets are the primary larval host plant for a wide range of butterflies called fritillaries. Violets are as essential to fritillaries as milkweeds are to monarchs. During late summer, the butterflies lay eggs in areas with violets. It is thought that some species of fritillaries are able to detect the scent or presence of violets from a wide range, even after the foliage has died back. The tiny caterpillars hatch in the fall and overwinter in leaf litter. Once the violets emerge in spring, the caterpillars begin munching on the tender new leaves.
If you have violets growing in your lawn, especially where this is some shade, you can convert your lawn to a native plant conservation area by following these steps:
- Cut the grass as short as possible (0ptional)
- Cover the area with a thick layer of leaves or other natural mulch (4-8 inches). The fall is a great time to do this.
- Consider covering the edges of the area with untreated burlap held in place with landscape staples. This can lock leaves in place without covering the whole area. Unlike cardboard which is sometimes used for this purpose, burlap is permeable and allows for movement of moisture, air, insects and other soil organisms.
- In several months, pull aside some of the leaves if needed, and the burlap. In most cases you will find your violets have spread while the grass is mostly dead.* The leaves can mostly be allowed to biodegrade in place.
- Keep any leaves you remove to use as mulch nearby – as described above there may be small caterpillars living on them!
*This process will not kill invasive perennial grasses such as Bermuda grass (Cynodon dactylon)
Sources:
Digital Atlas of the Virginia Flora | Viola sororia Willd
VNPS Native Plant Profile: Violets
NC Extension Gardener: Viola sororia
Myrmecochory: How Ants Shape Plant Communities | Xerces Society
Plants for Pollinators: Violets | Xerces Society
Andrenid Bees (Miner Bees) | Missouri Department of Conservation
Creating Habitat for Virginia’s Native Specialist Bees
Photo Credits:
Violet Miner Bee – LundbergJ (CC-BY-NC)
Split Open Seed Pod – Kaila Pennock
Meadow Fritillary – Iona (CC-BY)
Great Spangled Fritillary – Eug 302, no rights reserved (CC0)