July 25, 2021

Kreith: Consider containers to support pollinators

Pollinators are responsible for an estimated one in every three bites of food that humans consume, so it’s no wonder they’re getting a lot of buzz these days. For those who want to support these hard-working environmental contributors, but don’t have a large yard or space for a garden, containers may be the answer.

There are many factors to consider when creating a container garden that will attract and support pollinators throughout the growing season.

Identify a location for your container that receives full sun and fill it with numerous plants that will thrive in that condition. You will have the most success with plants that are drought tolerant. That way, you will not have to water as much. Annuals are a good choice, but you can also select Illinois native perennial plants.

One combination may be a short variety of zinnia — profusion series or pinwheel mix — as a border and cosmos as a centerpiece. Another option is lantana as a border and a shorter, 3 to 4 foot, variety of sunflower as a centerpiece. Marigolds serve as a border plant for annual blue salvia. I’ve had great success in attracting hummingbirds with “Black & Blue” salvia.

Native perennials that perform well in containers include purple coneflower, prairie blazing star, bottle gentian, lanceleaf coreopsis, prairie smoke and field pussytoes.

Herbs also can be planted in containers and some serve as pollinator host plants. Dill, fennel and parsley, for example, are host plants for the black swallowtail butterfly. Other herbs that work well in containers and have significant blooms include lavender, chive, nasturtium, thyme, basil, borage and hyssop.

Group herbs in containers based on their mature size and watering needs. Lavender and thyme are both fairly drought tolerant, so that would be one recommended combination.

Borage and nasturtium are another suggested combination. Borage will fill the bulk of the pot while a trailing variety of nasturtium will spill over the side of the container.

Choosing the appropriate container is important. It should be large enough to support the number of plants you wish to include and have drainage holes at the bottom.

When it comes to soil, Kreith recommends selecting a soilless potting mix that is peat or coir based and includes a mineral, such as perlite. This will allow for better drainage than a medium like topsoil, which clumps together. Add fertilizer or use a potting mix that already contains it.

Water the container as needed until water drips out of the bottom. If the pot is on the smaller side, watering requirements will be higher. During hot months, daily watering is typical. Larger containers will not dry out as fast, so every other day watering may be sufficient.

Be sure to deadhead spent flowers to encourage reblooming and avoid unwanted reseeding. Monitor your perennials for stress levels and replace if they become unsightly or die.

Once the season is over, containers can be brought indoors and overwintered in a garage, shed, or basement. If you’re going to leave them outside, group containers together in an area protected from wind, then water them and cover with a thermal blanket, straw, shredded leaves, or other mulch.

Nancy Kreith is a University of Illinois Extension horticulture educator.