Hello everyone,

Unlike previous plant of the month posts, this post will be focused on Kentucky bluegrass. Like most grasses (Poaceae), Kentucky bluegrass is wind pollinated, and does not require insect pollinators for its survival. Therefore Kentucky bluegrass does not support pollinators. However, we thought it would be a good idea to focus on this grass this month given the commonality and ecological impact Kentucky bluegrass has.

Kentucky bluegrass is a threat to biodiversity, a drain on resources, and a sign of conformity and status. Kentucky bluegrass is typically not worth the cost and the trouble.

Kentucky bluegrass (Poa pratensis) is a perennial grass that is native to Europe and Asia, but was introduced to North America by early settlers who wanted to use it as a pasture grass for their livestock. It is now the most commonly grown crop in the United States, covering millions of acres of lawns, golf courses, and parks. However, Kentucky bluegrass is a harmful plant that has many negative impacts on the environment and society.

One of the main problems with Kentucky bluegrass is that it outcompetes native plants. This reduces biodiversity. Kentucky bluegrass can spread rapidly and form dense monocultures, which, in addition to having negative impacts to biodiversity, can also negatively impact soil health. In Alberta, transforming natural landscapes with Kentucky bluegrass is of special concern as North American grasslands are one of the most endangered ecosystems in the world.

Another problem with Kentucky bluegrass is that it requires a lot of resources and maintenance, which can be quite costly and time consuming. Kentucky bluegrass needs more water and more nutrients than native grasses. This is especially concerning, considering the droughts and water shortages that many places are facing. Lawns require the equivalent of 200 gallons of drinking water per person per day. Additionally, fertilizer used on the grass can end up in waterways when it rains which harms the water ecosystems as it leads to algal blooms that use up the oxygen in the water causing the other organisms to die (eutrophication). This also impacts water quality. Kentucky bluegrass is also frequently mowed to maintain its appearance, which consumes fossil fuels and emits greenhouse gasses. Mowing lawns also gets rid of important nectar resources for pollinators.

The popularity of Kentucky bluegrass is likely due to its historical ties to wealth and status. As Kentucky bluegrass was becoming popular it could only be maintained by those with enough leisure time or money to take care of this crop. People still grow yards to fit in with their neighbours, which can be mandated by various homeowner associations. However, Kentucky bluegrass does not provide any useful functions, such as supporting pollinators or producing food.

Instead of having a Kentucky bluegrass yard, try planting a native wildflowers or native grasses as plants native to Calgary require less resources and have ecological benefits. If you undergo the process of naturalizing your yard make sure you are looking out for invasive species that can crop up, and make sure the plants you are planting are actually native to Calgary as many stores sell wildflower packs that include non-native species. Alberta Native Plants ( https://alclanativeplants.com/ ), Wild About Flowers ( https://www.wildaboutflowers.ca/ ) and the city of Calgary ( https://www.calgary.ca/water/programs/yardsmart.html ) are excellent resources to learn more about plants that are native to Calgary!

What is preventing you from naturalizing your yard?

The margined calligrapher (Toxomerus marginatus) belongs to the order of flies (Diptera), which is one of the most diverse groups of insects. More specifically, they belong in the hoverfly or flower fly family (Syrphidae). The name hoverfly comes from their ability to hover when flying, which is used during mating or feeding. The name flower fly may come from the fact that they are commonly seen pollinating flowers. There are about 900 species of hoverflies in North America.

Hoverflies typically mimic bees or wasps with their yellow and black striped abdomens. This is a form of Batesian mimicry, where a harmless organism resembles a harmful one to reduce its risk of predation. Hoverflies can be distinguished from bees or wasps as they only have one pair of wings, whereas bees and wasps have two pairs of wings. Hoverflies also have bigger eyes that are located at the front of their heads while wasps and bees have smaller eyes that are located at the sides of their heads. Hoverflies also have shorter antennae than wasps and bees. Hoverflies do not have stingers, and they are actually beneficial insects that eat plant pests and pollinate flowers.

The margined calligrapher (Toxomerus marginatus) belongs to a genus commonly referred to as the calligrapher flies, named for the fine black etchings found on their abdomens. These markings on the margined calligrapher form a closed margins around the sections of their abdomens. These markings help them mimic wasps or bees, however they are smaller than bees as they are typically only 5 to 6 mm. The female margined calligrapher can be distinguished from the males as the females eyes do not touch but the males eyes do. The margined calligrapher is found throughout North America, including Canada, the United States, and Mexico.

The adult margined calligraphers eat nectar, which gives them an incentive to visit and pollinate flowers. They visit flowers such as spiderwort, calico aster, groundsel, and whiteweed. The larvae, who are a light yellowish green, eat soft bodied insects which tend to be plant pests, including aphids and thrips. As the larvae feed on pests, the margined calligrapher can be considered a biological control agent.