A sterile hybrid, Giant Miscanthus is a tall-growing grass that is most commonly planted from rhizome pieces when the soil temperatures have reached 50 F. "But there are some things to consider if you are propagating and/or planting rhizomes this spring," says Emily Heaton, an Iowa State University agronomist who works with this crop as a potential source of bioenergy. Heaton and another ISU agronomist, Nicholas Boersma, provide the following information.
Giant Miscanthus (Miscanthus × giganteus) is a perennial warm-season grass used for bioenergy, and is being planted on thousands of acres in Missouri and Arkansas this spring. There are some farmers in Iowa who are planting it, just on a few acres to try it out. "Given the warm spring, and the high level of interest in Miscanthus this year, we have been getting lots of questions about propagation and planting," says Heaton.
A sterile hybrid, Giant Miscanthus is most commonly planted from rhizome pieces when the soil temperatures have reached 50 F, she says. Most farmers get their rhizomes from a commercial supplier. but those people who just want to play around with the new crop have been planting small plots that they can then dig up and propagate into larger stands at their leisure. Here are some things to consider if you are propagating and/or planting rhizomes this spring.
- If you want to dig up rhizomes from an established stand, it is best to do this while the stand is dormant, that is, after it has died back in the fall and before in emerges in the spring.
- If you are not replanting immediately, dig and separate the rhizomes, then keep them cool (approximately 40 F), making sure they don't dry out.
- If your Miscanthus has already emerged, you can still dig, but if you have expanded leaves, it is getting too late. Once the shoots get over 10 inches tall on average, you will start losing plants, and it is best to wait until the following year to dig. A rule of thumb might be that for every inch the stand is over 8 inches, you will lose 5% of the potential plants.
- Plant rhizomes in a weed-free row (can use strip tillage), making sure that all of the rhizome is covered, but not too deep; at least part of it should be within 2 inches of the soil surface.
- Good weed control is essential at establishment. Planting on a grid will allow for cultivation after the Miscanthus has emerged. Bicep, Harness and Harness Xtra are all labeled for use on Miscanthus for pre-emergent weed control.