Considerations in Carex Container Production

Key Points

Carex are relatively tough in the landscape but are more sensitive in production. They are well worth growing for their beauty, variety, and usefulness, and understanding how they are different from grasses is key. Unlike grasses, which can withstand unfavorable conditions for a while, Carex will show damage quickly when over fertilized or over watered. They tend to be more sensitive to soil moisture, salt concentrations, and temperature fluctuations. They’re slower growing than grasses, and take longer to finish and recover after being cut back. 

With their cool-season growth, you can get ahead by scheduling them for what are typically slow times in many nurseries' production cycle.

On this page, we'll share a few general guidelines for growing Carex in container production. These guidelines synthesize information from our growing team at Hoffman Nursery and articles on finished production from Paul Pilon of Perennial Solutions Consulting. Information on specific sedges can be found in their plant profiles; go to the Our Plants page to find them. 

Transplanting and Cultural Conditions

When transplanting liners, it's important to pot them at the original soil line and use well-drained media. Planting too deep or in media that stays constantly wet can lead to disease problems. When choosing what size to transplant, smaller liners tend to be better than larger ones, assuming you have time to finish them. Smaller sizes establish quickly and are less susceptible to transplant shock.

We grow Carex at slightly cooler temperatures than grasses, and we use partial shade on most of them. A 35% to 50% shade cloth post-transplanting and/or with intense sun works well. You can grow some Carex in full sun, especially if done early in the season.

Pests that might be typical on Carex (aphids, mealy bugs, and slugs) are rarely a problem. The most common diseases are rust and crown or root rots, which can usually be traced to planting too deeply or over watering. 

Water Management and Nutrition

Sedges have moderate water requirements. Most prefer to be kept moist, but several have average to below average moisture requirements. It's important to avoid over saturating them. Over watering can cause disease problems and discolored foliage. Using well-drained media and closely monitoring moisture levels will keep you ahead of problems. 

The Asian species are probably the most sensitive to water. If over watered, they may develop fungal problems, such as Rhizoctonia and crown rot. Keep New Zealand sedges slightly moist to dry. If you are overwintering sedges, keep them on the dry side to avoid rot. 

Carex are not heavy feeders and are sensitive to salt concentrations. We add a slow release fertilizer (SLR) at 2 lb./cu. yd. to our media at transplanting. The only time we add more is if we are overwintering a crop. Because granular feed can burn the crown, we only use it at transplanting. If we need to supplement feeding, we use a liquid formulation.

Early Season Sales

Pot up liners late summer or early fall.

Allow 6-8 weeks of good growing temperatures before dormancy and overwintering.

In spring, let the plants flush to market size.

With average temperatures of 60° F, plants typically finish in 7-8 weeks.

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Mid- to Late-Season Sales

Pot up during the same growing season as sales.

They will take slightly longer to finish than if they were overwintered.

With average temperatures of 70° F, a 72-cell liner would typically finish in 9-10 weeks. 

Click here to see a large version of the graphic.