December 11, 2024
How to design and plant your garden for pollinators

Last week, we published a story on Colorado pollinators that focused on the politics of how to support and get involved, including advocating for pollinator-friendly pest management. Here, we are focusing on how to design and plant for pollinators.

The summary: Pollinators need food, water and shelter.

Observe your microclimate to design

Much of the Denver area falls in the Plains and foothills life zones based on altitude and precipitation. As such, there are native plants that fit into each ecosystem, and some overlap. (For a deeper dive into this, check out the lists from the Colorado Native Plants Society of common and rare native plants per zone. Also, the National Wildlife Federation offers a free resource, Native Plant Finder, organized by zip code.)

One of the core principles of permaculture is to observe and interact, according to Jax McCray of Remedy Permaculture Designs, who conducts a Planting for Pollinators webinar hosted by People and Pollinators Action Network (PPAN). Observing your yard through the seasons shows sun patterns and other unique microclimate considerations to best plan out where and what to plant. It also helps you design a structure in three vegetation layers mimicking nature. Trees offer nesting, shelter, shade and food. Shrubs offer protection and food like chokecherry, woods rose, serviceberry. Then, filling in with perennials attracts pollinators with native plants like blue flax, yarrow, sunflowers, and Rocky Mountain bee plants, for example.

A moth on a flower
A cabbage moth on rocky mountain bee plant. (Tamara Yakaboski, Special to The Denver Post)

Reduce and replace turf lawn for pollinators

After moving into an old house with established grass, each year I reduce my turf by digging out a section and planting food or flowers. Slow and steady changes follows permaculture guidelines as it allows you to make it doable, see what works and ultimately have it be sustainable. Lawns use more resources such as water, fertilizer, pesticides and maintenance. And turf lawns offer no habitat or food to pollinators, whereas shrubs, for example, create food for birds and flowers, and shelter (as well as a block from our Colorado winds).

Good news for Colorado: House Bill 1151, the Turf Replacement Program, will allocate $2 million to financially incentivize replacing turf with water-wise landscaping. This promotes drought-tolerant plants, shrubs and bushes to divert less water from our rivers and reservoirs for landscaping.

If have turf grass, consider reducing lawn in areas where it is not used. Observe the use of all your areas of outdoor space. Perhaps there are corners or sides that are not used by children, dogs or humans. Removing the turf in those areas allows you to add in some select plants or even a Colorado wildflower seed mix.

If you want a ground cover to replace grass, creeping Oregon grape is a holly-like native flowering shrub. Or if you like the look of native grasses, Aaron Michael, founder and CEO of Earth Love Gardens, suggests blue gram grass as a full-sun ground cover (but it is not great for high traffic areas as it cannot hold up to regular stomping on). Buffalograss is another native warm-season grass that similarly goes dormant during droughts, although both it and blue gram grass have higher resistance when unmowed.

A black butterfly
A black swallowtail on dill. (Tamara Yakaboski, Special to The Denver Post)

Flowers feed the mind and stomach

Flowering plants capture the human imagination and fill us with joy while feeding pollinators with nectar and pollen. It’s a win-win situation. Evolutionary psychology shows that flowers elicit positive mood changes for humans. A pandemic study found that even certain colors — red and yellow, say, over white — boost relaxation and comfort. Green care or gardening benefits humans’ mental and physical health, medical research finds.

Just as flowers improve human health and wellbeing, native flowering plants and trees improve local pollinators’ health, too. While there are many flowering options, what is most optimal for the wide variety of pollinators are flowering native plants and trees. Flowers offer nectar and pollen to bees, moths, butterflies, bats and birds.

Keep in mind that pollinators that have a larvae stage also eat leaves of certain plants (think milkweed and monarchs, for example). The reminder here is to have plants that caterpillars like if you want butterflies and to know which pollinator likes what. The Western Tiger Swallowtail butterfly’s host plants for larvae are chokecherry and ash, yet the Black Swallowtail likes dill and carrot family plants.

Native plants are necessary to support local pollinator populations because they have specific needs for smells, flower shapes, nectar and pollen flavors not found in the typical box store varieties. Native plants tend to be more drought tolerant and less reliant on herbicides or synthetic fertilizers. Given rapid climate crisis weather shifts, we all need to select plants and trees that can tolerate less rain and warmer temperatures.

Finally, preliminary research in the UK shows that climate crisis impact on flowering plants leads to flower reduction, less nectar and fewer seeds. This means that we all must attend to our local areas and start to make up whatever difference we can in order to maintain pollinator populations.

A bee on a sunflower
A long-horned bee on a common sunflower. (Tamara Yakaboski, Special to The Denver Post)

Go for diversity of blooms for pollinators

Keep in mind that not all plants are visited by all types of pollinators. A selection of plants should be diverse in their offerings, bloom time, color, attractor  and the like.

Blooms throughout the season keep pollinators coming back to the same area, which is important for continuous support of population. Plant for blooms for early, mid and late seasons. Some of my favorite early-season options are blue flax, yarrow and Pasque flower. Mid-season ideas are milkweed and blanket flower. And late summer blooms delight with Blue Giant Hyssop, Rocky Mountain bee plant and the ubiquitous sunflower.

It is fun to geek out and have plants for specific pollinators, too. In keeping with the microclimate observations, see what visits your area first and what is missing. Monarch butterflies are a popular pollinator and important given their populations have seen a 80% to 99% decline and are facing extinction. Milkweed is one of those plants impacted negatively by a warming climate and drought. The Xerces Society lists the most common milkweeds for Colorado: spider (A. Asperula ssp.), plains (A. Pumila), swamp (A. Incarnata), showy (A. Speciosa) and horsetail (A. Subverticillata).

If you are a container gardener, many native plants work well in pots and even hanging baskets. There are dwarf varieties of sunflowers, but also goldenrod, blanket flowers and black-eyed Susan also grow in containers.

For more, the Colorado Native Plant Society offers an extensive list of low-water native plants for the Front Range and foothills. For birds, the Denver Audubon has a resource for native plants for them specifically.

Watch for People and Pollinators Action Network (PPAN) annual native seed exchange this fall. As a community effort, we all can pay it forward when we can and spread the message through free plants and seeds. This is a great way to participate in pollinator politics.