Problem-Free Production Scheduling for Panicum

finished panicum roots

Pot Panicum up in time to establish roots before they enter dormancy. That head start on root growth will give you a stronger, faster-finishing plant than if you’d potted it in the current season. Photo courtesy of Hoffman Nursery

Warm-season grasses like Panicum grow best when soil and air temperatures are high. They are some of the last grasses to break dormancy in spring, and their greatest growth occurs in midsummer. That has implications for planning your production. So let’s talk about finishing time and scheduling for Panicum production.

Advertisement

Typical Growth Cycle

Panicum virgatum is a warm-season grass that grows strongly through the heat and long, sunny days of summer. It is photoperiodic, with flowering connected to the change in day length that comes with the summer solstice. It flowers in mid- to late summer (July and August for Hoffman Nursery) and will show fall color as temperatures drop and day length shortens. Switchgrass is dormant through the colder winter months and begins growing again in late spring when soil and air temperatures are rising.

In our cold frames, Switchgrasses typically break dormancy around mid-March. They are one of the last groups to emerge, and bud break often varies by cultivar. Moreover, we see variations within crops, particularly with plants on the edges or in colder parts of the enclosure.

Top Articles
Two Horticulture Podcasts You’ll Want to Check Out

Scheduling for the Finish

Production conditions vary across regions, so we’ve synthesized some rules of thumb based on our experience, feedback from customers, and articles by perennial consultant Paul Pilon. Assuming 65°F to 70°F throughout crop production, a 32-cell liner should finish in a gallon in seven to nine weeks. A 72-cell liner to gallon should take 10 to 12 weeks.

If you’re aiming for one-gallon sales in late summer or fall, you can pot up in spring or early summer of the same year. Panicum virgatum’s late emergence becomes a plus because you can schedule them for after you’re done with other perennials. They’ll grow quickly once soil and temperatures rise.

When target sales are for spring or for 2 gallons or larger, the best strategy is to pot during summer or early fall of the preceding year and overwinter them. Make sure you pot them up in time to establish roots before they enter dormancy. That head start on root growth will give you a stronger, faster-finishing plant than if you’d potted it in the current season. This timing works for 1-gallon containers and for larger sizes.

Suggested Timing for Liners

Ideally, you’ve got liners ready to go when you need them and on your schedule. To do that with Switchgrass, it’s important to understand timing.

We work with Panicum’s natural growth cycle and only do production rounds certain times of year. For example, we make early spring crops of Switchgrass in late summer of the preceding year. If you’re bringing in liners for spring production, and you’ve reserved that spring crop, you’re all set. But if that spring crop sells out, you’ll have to wait until early summer when the next crop is ready. That can throw off your schedule and add to your costs. The smart move is to reserve them ahead of time.

Here are some guidelines to make sure you’ve got liners when you need them:

Target Potting Window  Reserve Liners by 
January-May  End of Previous July 
June-October  March of same year 
November-December  July of same year 

 

Bring It All Together

Getting your production timing down and working with Panicum’s natural growth cycle can help you take advantage of all that switchgrasses offer. Remember that they’re very efficient with water, nutrients, and sunlight when temperatures are high. These beautiful, adaptable, warm-season grasses have great growth potential and knowing how to manage that is key.


Learn More About Successful Panicum Production
This article is part of a series produced by Hoffman Nursery on problem-free panicum production. You can check out all the articles, as well as references and background information, at HoffmanNursery.com/blog. Part one focuses on understanding the range and warm-season nature of switchgrass. Part two talks about the fundamentals of container production and common concerns like yellowing and rust.

1