A Switchgrass Followup

In yesterday’s post on propagating switchgrasses I left out the picture of the ‘Northwind’ Switchgrass (Panicum virgatum). Also I didn’t post any details about the two switchgrasses that I mentioned. So here’s a little more about switchgrasses!

Switchgrasses are native to the United States and flourish during the warm season. In my observations they are later to emerge from winter dormancy than other grasses like miscanthus. ‘Shenandoah’ Switchgrass grows between 3 and 4 feet tall and is one of the shorter varieties of panicum available for ornamental use.

The two ‘Shenandoah’ switchgrasses I have in our backyard gardens are different sizes even though the plants started out the same. The taller of the two fits in the between 3 and 4 foot range but the other one is much shorter and also has a smaller width. I believe this is due to the sun conditions which favor the larger ‘Shenandoah’. It receives about 1.5 to 2 hours more of natural sunlight than its companion. The more sun the switchgrass receives the more vigorous it grows.

The ‘Northwind’ switchgrass is near the road in the mailbox garden (which really needs some work!) It gets full sun but has grown as tall as they say mostly because of the hard compacted clay soil where it is growing. The roadside area is one of the worst spots in our yard to grow plants because when our community was created some areas were completely scraped of any soil during the grading process. What was left was the clay and gravel leftover from construction. I’ve gradually added mulch and compost to the area but “Rome wasn’t built in a day”!

Update from 2020: The one key to growing switchgrass successfully is sunlight. As your garden changes (trees grow making more shade) the conditions may change. Switchgrass absolutely needs a good day of sun to thrive. At a minimum 6 hours of sunlight but preferably 8 or more in the summer. Switchgrass will fail in the shade.

The poor soil doesn’t prevent this switchgrass from performing well but does keep it from its potential. ‘Northwind’ should eventually grow between 4 and 5 feet tall but our second year plant is just a little over three feet in height. As the soil loosens, compost is added and rain resumes conditions should improve for my ‘Northwind’.

One switchgrass that is on my radar is ‘Prairie Fire’ which resembles a ‘Shenandoah’ on steroids. The red coloring that emerges in summer seems much deeper and darker than ‘Shenandoah’. It’s height varies depending on where you look and could be anywhere between 3-6 feet (according to Fine Gardening Magazine).  I haven’t seen it sold near me yet but I’ll be on the lookout!