May 2021 Culture, Variety Info

Culture Report: Schizachyrium scoparium ‘Shining Star’ By Josiah Raymer

Little bluestems, along with being North American natives, are a favorite around our greenhouse, and this one strikes a chord for its big impact — it’s variegated! ‘Shining Star’ stood out immediately in our in-house variety field trials. It was one of those unquestionable selections, and one that helps put some cool into a native grass. It starts out sneakily subtle in the classic schizachyrium mounding habit, but then its fine, delicate foliage starts to surprise — and keeps the color coming.

Pretty with its variegated cream and green blades at emergence and into summer, it becomes truly striking with age and maturity. Cooler temperatures bring a deepening and blushing of pink and darker pink, starting at the leaf tip and progressing to stun into autumn. Small, puffy flowers on upright, variegated stems join the party in mid- to late summer to keep things even more interesting and textural.

Not familiar with the new schizachyriums? Get to know them for their
ease of production and equally great ornamental value. They’re one of those underutilized grasses that can do just about anything. Often with the species schizachyrium, we’d see issues with sprawl or lodging. This can happen with many grasses as a result of over-fertilization but also as a characteristic of the specific selection. Making new, improved selections based on an upright strong habit that is resistant to lodging gets rid of this problem for grower — and ultimately the end consumer. This cultivar checks that box and gives us lasting winter interest we didn’t know we were missing.

Added to that, the species did great on the prairie or in masses, where ‘Shining Star’ hits that perfect size range that makes it suitable for landscapes and containers alike. It works great in borders, as a screen or as the “thriller” in a great combination planter. Foliage reaches 15 to 18 inches; the plant tops 30 inches in bloom. Spread is about 30 inches as well, and ‘Shining Star’ stays sturdy, keeping a nice, compact form without lodging in foul weather. A couple added benefits: deer resistance and drought tolerance once it’s established.

TRANSPLANT AND GROWING ON

Production-wise, schizachyrium is all about moderation — moderate fertility, nutrition, and temperature water. The only thing it likes a lot of is light. Like most schizachyriums, ‘Shining Star’ suits a 1-gallon pot well. Plant one 38-cell liner per pot. You could go bigger if you have a market for the increasingly popular robust showstopper pots. If you bump up to a 2- or even 3-gallon container, you’ll want to increase to two and three plants per gallon respectively.

Choose a well-draining commercial media. Your optimum pH level is 5.8 to 6.2 — schizachyrium can tolerate an alkaline soil, but prefers a little acid. Your electrical conductivity (EC) level should be between 0.8 and 1.2 using the 2:1 extraction method. Consider a preventive fungicide drench at liner transplant. Plants should finish for spring sales in approximately eight to 10 weeks.

WATERING

This little bluestem doesn’t love to have its feet wet. Let plants dry between ample watering. Avoid over-irrigation. Using a well-draining mix will make this less of an issue.

GREENHOUSE TEMPERATURE

Maintain greenhouse temperatures at 65 to 75° F during the day. At night, temperatures should be in the range of 55 to 65° F. Watch humidity levels. No vernalization necessary.

LIGHT

‘Shining Star’ likes high light — aim for light intensity at 5,000 footcandles or more. You may want to add supplemental lighting as well, depending on time of year and greenhouse conditions.

NUTRITION

Like many warm-season grasses, schizachyrium likes a moderate fertility level. Start with mid-range levels of nitrogen in a constant liquid feed at 100 to 150 ppm, and continue through finishing. For periodic fertilization, go with a nitrogen level of 250 to 300 ppm, and apply as needed. Err on the side of less fertilizer when in doubt, to avoid stretching and increased disease susceptibility.

FINISHING

Follow a monthly broad spectrum fungicide control program to keep the foliage clean. With proper sanitation and prevention protocols in place, pest and disease should not be an issue. Scout and monitor carefully for the usual pests. Keep foliage as dry as is practical, and do not over water. Provide proper spacing and ventilation. This, along with managing water and fertilizer levels, should be enough to help manage plant height to maximize shipping efficiency. (Plant growth regulators generally aren’t needed on schizachyrium.) If you’re going to be overwintering or holding Schizachyrium for an extended time, you may consider adding a little bit of bark to the mix to help balance water holding and drainage.