When it comes to pollinator gardens, not all are created equal. In fact, we were surprised to learn that many plants advertised as “pollinator friendly” actually do more harm than good, either because they do not support the entire life span of pollinators and threaten native species that do, or because they are grown with toxic pesticides that can remain for years. For the conscientious garden, a chemical-free, native pollinator garden is the best choice.
With the help of New England Wild Flower Society, we are learning more about effective native pollinator gardens through the program Pollinate New England, an initiative made possible by a grant from the Institute of Museum and Library Services. I attended one of the society’s lectures and demonstrations to learn all about how to plant my very own native pollinator garden. (Though the organization is New England–based, their native gardening practices can be applied throughout the world.)
Photography by Justine Hand for Gardenista.
Why plant a native pollinator garden?
Pollinators are essential because they allow plants to reproduce. Yet, throughout the world this vital group is in crisis. Habitat loss, fragmentation, and the widespread use of chemical pesticides are threatening the insects, birds, and bats that are a crucial part of our ecosystems. Among these, native pollinators are among the most sensitive to these environmental and man-made pressures, because they require specific plants to survive, which are also threatened by habitat loss and invasive species.
Fortunately, even the smallest native garden can help. From urban rooftop gardens to vase country estates, all you need is a small plot to help struggling native pollinators.
1. Choose native plants to help native pollinators.
Unfortunately, many plants that are advertised as supporting pollinators are either ineffective or may actually cause harm to native pollinators for several reasons:
- They may only support the adult cycle, providing nectar for mature pollinators, but no food for the larvae of native species. Butterfly bush (Buddleia davidii) is such a plant. In the western hemisphere, butterfly adults may feed on the purple blooms of this Asian import, but their larvae cannot eat the leaves.
- Non-regional plants may support insects that supplant local pollinator populations. Most native pollinators require very specific plants in order to grow and thrive. For example larvae of Karner blue, Persius duskywing, and frosted elfin butterflies feed only on wild lupine Lupinus perennis, not the more common L. polyphyllus which has supplanted most native lupine throughout the region. As a result both these butterflies and the plant they rely on are critically endangered.
- Most insidiously, many garden center plants have been grown using systemic pesticides or neonicotinoids, water soluble chemicals that kill or harm pollinators. Not only do these chemicals kill pests in the area where they are used, they also kill pollinators. Furthermore the effects can be transferred to your garden, as these harmful chemicals have been shown to remain in the leaves and pollen of treated plants up to seven years after application.
Fortunately, your local native plant or botanical society often sells organically grown, native plants or can provide you with a list of plants that support native pollinators, and where to find them. For example, you can find which plants are native to your ecoregion on the New England Wild Flower Society website. Many of these plants are available at Garden in the Woods or Nasami Farms. A quick Internet search can reveal both local and online suppliers of chemical-free, native plants.
2. Know the components of a native pollinator garden.
The New England Wild Flower Society has published a list of “Pollinator Garden Best Practices,” which recommends including the following in your garden:
- Adult Food: A diverse selection of native plants with “abundant pollen and nectar across the growing season, planted in groups for easy foraging.”
- Baby Food: Host plants for butterfly and moth larvae.
- Water: Muddy spots where insects can access water and soil minerals, as well as well-drained places for ground nesting.
- Habitat: Nesting materials and other protective habitats such as hollow-stemmed plants, decaying wood, leaves, grasses, and bare soil, to help support the entire life cycle of threatened pollinators.
- Protection: Use only plants grown in chemical-free environments. And be sure to spread the word. Tell friends and neighbors not to use pesticides or to purchase plants grown with harmful chemicals.
3. Do your research before you plant.
I joined a group at the Wellesley, Massachusetts, police department for a native pollinator garden lecture and demonstration led by Annie White, an ecological landscape designer who teaches at the University of Vermont and performs research on pollinators, as well as Mark Richardson, the botanical director at New England Wild Flower Society. What follows is an abridged version of what we learned. For more complete information about planting your own pollinator garden, attend one of New England Wild Flower Society’s lectures or demos listed here.
4. Conduct a site analysis.
The first hands-on step to create a pollinator garden is to assess the qualities of your garden site to determine which native plant species will be most successful there. By practicing “right plant for the right place,” you will cut down on the time and resources needed to help your garden thrive. Consider the following:
- Sunlight: How much sun does your garden site get? Full sun is six or more hours per day (three to six house is part sun, and a few hours of sunlight is shade). Also note the timing of the sun. Midday sun and southern exposure will be much stronger than morning and evening light. Note that the sunnier the site, the greater diversity of plants it will support.
- Soil: Test your soil to determine its characteristics: composition (sandy versus clay), pH balance, as well as nutrient levels. Do not try to amend your soil with chemical fertilizers. Use only organic compounds, such as compost and mulch, to enhance your soil.
- Moisture levels
- Wind exposure
- Wildlife: Consider wildlife pressures such as deer and rodents. If these pests are present, opt for resistant plants or organic deterrents such as a liquid fence.
- Aesthetics: Native pollinator gardens have an informal appeal. Plant them where they will complement your landscaping scheme.
5. Prepare the site.
To prepare your native pollinator garden site:
- Remove all sod and other nondesired plants, especially invasive species.
- Till the soil to make it easier to work with.
- If necessary, add top soil.
- Add 1 or 2 inches of organic compost on top of existing soil. Select only fresh, local compost as this will ensure that the microbes are still active.
6. Lay out the garden and choose plants.
As with any garden, the next factor in determining what to plant in your garden is your hardiness zone. New England gardeners may visit Garden in the Woods or Nasami Farms for the best selection of New England natives. You also can purchase one of the New England Wild Flower Society’s three ready-made Pollinator Kits, which are designed to thrive in varied sun and soil conditions; $180. Each kit contains 50 plug-sized plants that will cover approximately 120 square feet.
Here are a few things to consider in your design:
- Select a variety of flowers that bloom throughout the season, as well as plants that support larvae, and species with protective habits (such as grasses and stocky plants).
- Consider the growing habits of the plants when making your selections. If you don’t want spread, reconsider that goldenrod.
- Plan for one plant per square foot. Denser plantings like these help lock in moisture and reduce weeds. Select plants in smaller containers versus larger gallon sizes, as these are more economical and are easier to plant.
- Plant taller plants toward the center of your garden so they are easier to reach.
- Create “massings” of four to five plants together. This practice not only makes it easier for pollinators to forage, it also creates what Annie calls more “legibility” in your wildflower garden.
- Group moisture-loving plants together to save on water bills.
- Disperse color and bloom time throughout your garden.
- Leave a border of several inches for spread and mulch.
Tip: When buying plants always ask for them by the botanical name so you don’t get a cultivar which is not as good for pollinators; they are less genetically diverse and the plants tend to bloom all at the same time.
Tip: Beware of pollinator seed mixes—which are often chock-full of annuals, non-natives, and even invasive species.
7. Plant the natives.
- Lay your plants out according to your design. This practice helps maintain even spacing and allows for any last-minute design tweaks.
- Break up the root system of your plant.
- Use a trowel or hori-hori knife (See My Most Versatile Garden Tool: Hori Hori Knife) to dig a hole that is deep enough to accommodate the existing root system.
- Place the plant in the hole and fill in with dirt. Repeat until all your plants are planted.
- Water the entire garden. A water wand is recommended for new plants, which can be more delicate.
- Add a layer of natural mulch such as pine bark. Avoid dyed mulch or mulch with big chunks. Don’t mulch right up to the plant.
8. Care for the pollinator garden.
To help your native pollinator garden grow:
- Water your garden often during the first year. You can buy a rain gauge to help maintain the recommended inch of water per week.
- Water smaller gardens by hand so you can keep an eye both on the weeds’ and the plants’ progress.
- Weed by hand.
- In fall, leave seed heads and stalks to provide food and habitat for birds and overwintering insects. You can also add a little leaf mulch in fall.
- Cut back in spring.
- Add compost in spring.
- Never use weed killers, chemical fertilizers, or pesticides.
To learn more about native plant gardening: