Hakonechloa ‘Aureola’ was a Perennial Plant of the Year and is still a great choice for shade mixed containers.
Photos courtesy of ECG

With the massive popularity of mixed containers today, chances are if you haven’t tried your hand at combinations, you’ve likely thought about it. And if you’ve tried it without some serious forethought and preparation, you may have ended up frustrated or less than satisfied with the results. It’s important to coordinate color, foliage and texture for an aesthetically pleasing combination, but the production requirements of each plant are equally important. Matching water, light and size requirements is critical for maximum salability and success with mixed containers. Here are a few tips and tricks we’ve compiled over the years.

Meeting light requirements

Coordinating the light requirements of the components in your mixed container is a must.

This is especially important with ornamental grasses if you’re creating containers for shady areas. It will limit the different grasses that you can use, but it’s critical. For example, many popular ornamental grasses such as Panicum, Miscanthus and Pennisetum need full sun to perform well. Low light can result in weak or leggy growth or reduced flowering. Therefore, combining them with containers of plants intended for shade will likely backfire and potentially lead to a dissatisfied customer.

If you’re making shade-tolerant mixed containers and need a grass, consider using a Hakonechloa or grass-like plants such as Acorus or Carex.

Here’s a great combination with Pennisetum First Knight, Carex Toffee Twist, Sedum Lemon Ball, Salvia Black and Blue and Ajuga Black Scallop. Tip: If you’re using a fast-growing pennisetum with slower perennials, you may want to let the perennials establish in the container with an empty pot where the pennisetum will go.

Managing water requirements

It’s important to keep each plant’s water requirements in mind so that you don’t end up with perennials that love good drainage mixed in with grasses that like wet feet. Adjust your planting mix to suit the drier plants; it’s easier to water more often than to have plants sitting too wet.

Establishing the container

If you plan on using an ornamental grass in a container, timing of planting can be important.

A good approach to consider: Establishing slower-growing perennials or grasses in the container with a placeholder pot for a faster growing ornamental grass.

For example, if you’re planning on using a fast-growing Pennisetum such as First Knight in your container with slower perennials, you may want to let the perennials establish in the container with an empty placeholder pot where the First Knight will eventually go. This will keep the First Knight from out-competing the slower plants while they establish and leave you with a healthier finished product.

Matching sizes

Many ornamental grasses will be slightly reduced in size when placed into a mixed container, but large grasses will still need a large container to perform well. For example, a 4- to 5-foot grass in a landscape may only be 2 to 3 feet in a container, but it will still need at least a container that holds 3 to 5 gallons of media.

Large aggressive grasses will also tend to outcompete slower growing perennials and should be planned for accordingly when used in combination. Increasing the size of the container can provide extra room for the perennials to grow. Again, this comes down to matching the container size to the application.

Josiah Raymer is head grower and general manager for Emerald Coast Growers, one of the country’s largest ornamental grass and perennial producers. www.ecgrowers.com