Wild violets for lawns

Violets for lawns poster
From left to right: Viola sororia var. alba, V. sororia cult. “Freckles”, V. pubescens

 

In an earlier post on violets (Spring flowers – wild violets) I presented wild violets that typically grow in woods and fields. The violets shown here also grow in wild habitat but do very well in lawns. Two easy to grow species are shown. The first is Viola sororia, the sisterly violet, with two varieties. The white one is V. sororia variety alba and the speckled one is V. sororia cultivar “Freckles”. The usual color of V. sororia is deep blue and this color form can also be grown in lawns. It is tolerant of partial shade and likes average loamy soil that does not dry out too fast. In the wild V. sororia grows in moist to dry meadows and woodland edges from Manitoba east to New Brunswick and south to Texas and Florida.

The other violet shown is V. pubescens, the downy yellow violet. Like V. sororia it is easy to grow in lawns and has similar soil and moisture requirements. Wild plants grow in mesic deciduous forests across eastern Canada from Ontario to New Brunswick and the US south to Virginia.

Both species and their various cultivars can be bought from plant nurseries. You could also collect seeds from wild colonies and start plants that way. In about two or three years they will become established in the lawn and begin to spread to other places. You can take large violet plants and carefully divided them to plant in other areas of your lawn.

I do not mow my lawn until the plants have finished blooming. That way seeds will be able to mature and start new plants elsewhere. Additionally, these large-leaved violet species are larval host plants for certain species of fritillary butterflies.

Purple Prairie-Clover

 

This pretty flower is purple prairie-clover (Dalea purpurea) and is one of my rescue plants. I found this purple prairie-clover plant growing along the side of a road (which has experienced major reconstruction in recent years) on the bluffs overlooking Duluth, Minnesota. I had seen it growing there with several other prairie plant species for years and would even make special hiking trips just to look at it and the others in bloom. I’d also go there to collect flower tops and leaves of wild bergamot (Monarda fistulosa) and licorice mint (Agastache foeniculum) for teas. Not knowing any better at the time (it was 1993) I dug up a plant and luckily it survived my clumsy work. I watered it often and kept the plant protected from the sun with a sheet of cardboard. It has been a slow growing plant for me and from the one original I now have three plants.

Taxonomy, Distribution, and Description

Purple prairie-clover (Dalea purpurea) is a legume in the family Fabaceae but is not a clover (Trifolium) which is a genus of plants separate from this one. Purple prairie-clover grows in dry to mesic prairies, both tallgrass and shortgrass, other grassland types, and oak savannas from British Columbia and Manitoba in Canada south to Alabama and Arizona in the United States. Although considered an indicator of stable plant communities that have existed with little soil disturbance (such as erosion, plowing, heavy grazing) purple prairie-clover will colonize disturbed soils likeĀ along roadsides.

Purple prairie-clover is a perennial herbaceous plant from a deep woody tap root with several lateral roots thatĀ can be from 1 to 2 meters long in mature plants. New growth comes from buds at the crown of the tap root. There may be from 2 to 15 stems. The leaves with from 3 to 7 leaflets are small (1 to 4 cm long), numerous, fine textured, with translucent glandular dots, and scattered hairs along the margins. Purple flowers appear from late June to August on the 20 to 90 cm high stems and are later followed by grayish cones of small one-seeded or two-seeded pods.

In the garden

Purple prairie-clover will grow in any deep soil that is dry or well-drained and in full sun. Plants or seeds may be purchased from many sources that specialize in native plants. Sow the seeds where the plants are to grow or in deep pots to be transplanted later. If direct sowing remove any sod and weeds and plant in the fall at a depth twice the thickness of the seeds. Growth can be slow and weeding will be necessary for a few years.

The combination of purple prairie-clover’s fine-textured leaves and short spires of purple flowers is quite attractive when mixed with short bunching grasses such as little bluestem (Schizachyrium scoparium) and prairie dropseed (Sporobolus heterolepis) and low-growing herbs such as white sage (Artemisia ludoviciana).

References consulted

Cochrane, T. S. and Iltis, H. H. (2000). Technical Bulletin No. 191. Wisconsin Department of Natural Resources and University of Wisconsin-Madison Herbarium.

Gleason, H. and Cronquist, A. (1991). Manual of the Vascular Plants of the Northeastern United States and Adjacent Canada, Second Edition. New York Botanical Garden, New York.

The variety in wild iris

Iris versicolor

 

There is only one native wild iris in northern Minnesota and that is the northern blue flag (Iris versicolor). This iris prefers wet habitats such as sedge meadows, swamps, river banks, shores, and ephemeral ponds. On my land there must be several hundred plants and almost all of them have been in full bloom for the last three weeks. In some places the view is spectacular.

Northern blue flag spreads by seeds and rhizomes (cloning). I have been looking at the wild iris here for many years and have noted that each clone differs a little from its neighboring clones. Some produce flowers with very straight petals, others are more rounded. There are clones with flowers in shades of blue ranging from gray-blue to almost purple. A few have so little blue color that they are almost white. The greenish-yellow spot on the fall petal can vary, too, in its size and in degree of yellowness. This year I have made a special effort to look at the wild iris more closely in order to find more variations.

Downy Phlox

Downy phlox (Phlox pillosa)
Downy phlox (Phlox pilosa)

 

Downy phlox (Phlox pilosa) is an inhabitant of jack pine barrens such as those in Washburn County, Wisconsin where it occurs with other drought tolerant species on sandy soils with only a thin layer of organic matter. It is short plant (to 0.5 meter) with long-linear, fuzzy (“pilose”) leaves arranged in opposite pairs along the stem. The pale lavender to pink fragrant flowers are borne at the top of the stems and appear from May to early June.

Downy phlox is easily grown in gardens with rapidly draining coarse or sandy soil in full sun. New plants can be started from seed planted in the fall where the plants are to be grown. Stolons (the leaves are rounded on these) that have rooted can be carefully cut from the parent plant and replanted. Growth is slow whether propagation is by seed or divisions made from rooted stolons. Too much shade or competition from faster growing plants is not tolerated by downy phlox. Downy phlox does best along the outer edges of the flower garden or in prairie plant gardens with short grasses and forbs. In prairie gardens it is a good idea to burn the grasses every few years in the spring. Burning will create open spaces where downy phlox and other shade intolerant forbs may grow.

Phlox flowers are attractive nectar sources for hummingbirds, many species of butterflies, and white-lined sphinx and clearwing moths (Sphingidae). Besides being a nectar source downy phlox is also the exclusive larval host plant for the phlox moth (Schinia indiana) which is scarce throughout its range owing to the near destruction of native prairies. The larva of phlox moth bore into the flowers and eat them but later eat the developing fruit from the outside. Their development is slow and takes almost a full year from egg to adult moth.

I have planted a few purchased downy phlox in one of my flower gardens. Their increase has been slow and although sphingid moths visit the flowers I have not yet seen any phlox moths. This is hardly surprising given that I live far from any large populations of downy phlox and jack pine barrens habitat. But maybe some day they will arrive.