Q&A: Top ornamental grasses and sedges production tips

Growers are considering diversifying their crop mix more and more as the industry deals with young plant shortages due to the ongoing pandemic and its seemingly never-ending reverberations.

One of those crops that is being spotlighted more and more by ornamental greenhouse operations are ornamental sedges and grasses, which are also in high demand currently as landscapers and home builders are completing projects at a dizzying pace this spring and summer.

Read on for some of Cavano’s Perennials, a wholesale container nursery located on two properties in Kingsville, Maryland, just northeast of Baltimore, top tips for growers thinking about adding grasses and sedges to the production cycle.

Greenhouse Management (GM): What are a few of the more trending varieties of ornamental grasses this season, and are there any trends (pollinator friendly, vivid colors, interesting exotic shapes/compositions, drought-tolerant) that you can see that are driving these varieties popularity?

Cavano’s: “Grasses (including sedges and rushes) and their popularity have been project driven, native driven, eco-driven, and aesthetic driven. Since grasses, sedges and rushes are wind pollinated, they offer very little for pollinators. However, they are larval host plants for many Skipper species (like the Dotted Skipper which uses Panicum or Switchgrass as their main larval host). 

In the past few seasons, projects and the native movement have really made an impact on our choices. Andropogon virginicus, Deschampsia cespitosa, Sporobolus heterolepis, Nassella tenuissima, Sesleria autumnalis, and Juncus effusus have all seen increases. Panicum and Schizachyrium species and cultivars have been in great demand. We are particularly excited to see cultivars of these species with selections for color, habit, and size. For example:

• Andropogon cultivars from Intrinsic Perennial Gardens - Andropogon gerardii ‘Blackhawks’, ‘Dancing Wind’, and ‘Red October’.
• Schizachyrium cultivars continue to improve, Schizachyrium ‘Standing Ovation’ is one of our best sellers.
• Panicum ‘Cape Breeze’ from North Creek Nurseries is a favorite, too. It sells well and we have used it extensively in our own gardens across the nursery.

Sedges are also exciting, not for cultivars, but for sheer diversity of the species. Carex pensylvanica has always been our biggest selling sedge. Expansion of interest in sedges has seen us add Carex appalachica, Carex stricta, Carex amphibola, Carex flaccosperma and countless others. Cultivars like Carex grayi ‘New Moon Mighty’ and Carex pensylvanica ‘Straw Hat’ are being recognized and requested.

Hakonechloa is in massive demand, too, and our first cycle was sold out in just a few weeks this year. We are hoping that this grass boom sees not only an expansion of cultivars and breeding efforts, but also more diversity of the grasses, sedges, and rushes offered.”

GM: Production-wise, what are some practical tips for producing ornamental grasses in the greenhouse? I understand some of the varieties can be difficult at times to root, any suggestions there?

Cavano’s: “We begin by viewing any production as a manufacturing process. You do not build a car the same way as a computer, but you use the same principles. So, we approach production from the manufacturing side - how can we get the most production done at the highest quality level and scale.

We are then examining the horticultural and biological side of production. Proper timing of cool season vs. warm season grasses is one of our biggest factors. Sitting down with our team and making sure everybody involved truly knows the difference between warm season and cool season species and varieties.

Next would-be location and care. The diversity of the category is challenging to any horticulturist responsible for growing these crops; we have and continue to develop a modular based zoning process to assist our production and propagation teams. Our growing crews try and find the best compromise of scale and care. The standard location for a species might differ depending on the time of season; cool season grasses migrate into shade structures and houses while warm season plants move to field production. Our summer production cycle for warm season grasses is huge, a quarter of a million plants. So, division of labor and a proper production cycle/timing is essential to be successful.

The organization of proper irrigation, fertilization, and spray schedules is a must, as many of these plants have quite different needs. We also have been very devoted to rethinking the media we use. A few years ago, we added a member to our management team with a strong background in soil science. We have enlisted the aid of our media suppliers and their technicians and in addition to top experts at the extension service and universities, in hopes of growing better higher quality product.

We have been selecting the best media for grasses, sedges, and rushes we can find, using first principles to engineer better media for specific plants to grow. Schizachryium and Juncus have vastly different needs, approaching the production schedule starting with media has yielded better plants and less loss.

Lastly, we look at our care regiment. The placement and media help us eliminate issues such as over or under watering, poor nutrient uptake, and focus on root development. Healthy roots allow for a more robust healthy plant resulting in a better crop cycle.

The current market and demand give us some freedom as well; offering a diversity of sizing (quarts, #1s, and #2s), allows us to have more plants available for sale at different times throughout the season. Our expansion of quart production gives the customer access of purchase and allows us to grow product for turn. This has become particularly important in sedges and cool season grasses.”

GM: Are there any automation technologies (pot fillers, stickers, moving benches) that have proven helpful in ornamental grass production in the greenhouse?

Cavano’s: “Technology, like overhead irrigation and potting machines, play a massive part in our grass production. But again, we always look to our teams; developing strategies and structures that allow for proper use of these technologies. Without a proper production plan, a set of goals, and continual development of higher standards, we won’t produce the best crop. If we as a team set goals, we need to make quality decisions and execute well on them.

Technology frees our teams to make better judgments and reach for higher goals, otherwise we could not accomplish our scale or quality of production. We have been looking at updating much of our current equipment after the 2020 demand and the pace of the 2021 season. We have already begun the process of planning for the 2022 season and are in communication with our vendors for the 2023 season as well.”

GM: Any other big picture, 30,000 foot tips to leave the growers with?

Cavano’s: “We try not to be too myopic in our approach, but we start big; we look at the scope and scale of production and identify areas for special focus and specific approach. We make short term and long-term decisions and that takes time, balancing short term profits with investment in future growth.  Like the saying goes “business is 1% strategy and 99% execution”, you must continue to plan and adjust for both the short and long-term.

We look at the primary demands of growing grasses and look at specific needs of each species. This leads us to develop growing zones and collective areas for grasses with similar needs, allowing our growers better chance for success and more profitable crop cycles. So, planning and then more planning.

Observation after implementation of both mistakes and failures will always occur, but adaptation and realization of these issues require speedy well thought responses. “Our people succeed because we allow them to fail” is one of our president Ferenc’s favorite quotes. Give yourself room to improve in your production plans.”