Wednesday, July 29, 2015
Sunshine Mimosa - Mimosa strigillosa
Sunshine mimosa is extremely hardy and spreads aggressively. It sends a great many stems (stolons) out in all directions from the main stem and they root periodically at the leaf nodes. The reddish stems and deep green foliage hug the ground and rarely stand more than 3-4 inches tall. In sunny locations, this makes a dense ground cover and this plant is often used as an alternative to turf grass. Sunshine mimosa is a legume and it exhibits the typical pinnately compound foliage. The leaves are not sensitive to touch as is that of sensitive briar (Mimosa quadrivalvis) - a plant it is sometimes confused with. The foliage also serves as one of many host plants for the Little Yellow butterfly.
Like other members of this genus, sunshine mimosa produces pink "powder puff" blooms. These are produced on single stems along the length of the runners and they stand about 6 inches above the foliage beneath. Flowering occurs from spring through fall and each bloom remains intact for more than a week. There are no petals; the pink blooms are composed only of the male and female reproductive parts. They are moderately visited by small pollinating insects.
Sunshine mimosa can be a curse or a godsend in the landscape depending on the setting and the goals you have for it. Though naturally present in moist soil habitats, it is extremely drought tolerant and adaptable to nearly any soil type. Its roots are stout and woody, and reach several feet deep into the soil column. Over time, its spreading habit and dense foliage (which is reduced in winter, but still present) form a dense cover that limits weeds and unwanted plants, but also out-competes most other desirable wildflowers. Therefore, it does not make a good addition to a mixed wildflower garden. Its aggressive nature also makes it difficult to contain unless surrounded by concrete or asphalt. The few plants added to our landscape by my wife over a decade ago, quickly left our yard and now comprise most of our next door neighbor's yard, from our property line all the way to his driveway, 50 feet away. As they are not gardeners, they are happy to have this low-maintenance "lawn". If it had been another neighbor, however, we might have caused problems. Sunshine mimosa can be contained also by shade. It greatly prefers full or half-day sun and fizzles out beneath a shady canopy.
In the right location, this is a very valuable and attractive ground cover. Because of this, it is widely propagated and should be easy to find at commercial nurseries - even ones that don't specifically carry native plants. Just make sure that your landscape goals will not conflict with this plant's growth habit.