So You Want to Support Pollinators - Part 2

Leaf cutter bee on Rudbeckia fulgida

Last week I wrote about understanding the benefits of changing your landscape to support pollinators. I laid out the basics of the concept: knowing the difference between needing food (larval host) plants and nectar plants. If you missed that post, you can find it here. This post is about How to Start, specifically evaluating your space and choosing the plants.

For those of us in Georgia, now is a great time to be planning. Spring native plant sales start in about 2 weeks so you’ll have plenty of opportunities to pick up the plants you chose for your new space. Before we pick out any plants, however, we’ve got to understand the space. The two most important considerations are the physical conditions of light and moisture.

Light – the range of light varies with the location (North-facing, South, etc.) as well as any nearby tree canopy. Most pollinator gardens want to maximize blooms so we’ll want a location that gets good sunlight. Full sun conditions are defined has having 6 or more hours of fairly direct sun each day. Whether you get sun hours in the morning (the kindest of lights) or the afternoon (harsh light) or a combination of both, the total hours in the growing season (when nearby trees have leaves) needs to be at least 6.

You can measure your light in the area on a sunny day when you are around all day. A clever method that I read about has you put down a marker for every hour that you go outside and the area has full sun; you can use popsicle sticks, utility flags, marbles or even just mark it on a piece of paper. Go outside at the same time each hour and check. Then count up all your markers to get the number of sun hours. If the area varies (half of it gets 6 hours but the other half gets 5, for example), then make a note that you might be choosing part-sun plants for the shadier half.  You may have to re-evaluate during the blooming season if there are a lot of trees that cast more shade than you thought.

Moisture – while most basically broken down in wet and dry, we know that there are places in between those two extremes. There are locations that are consistently moist, others that are soggy after a rain (but dry out later), and some places that are generally average-to-dry all the time. This is hard to evaluate in a day; you’ll need to have a longer period (or perhaps you already know).

Turtlehead (Chelone glabra) is good for wet spots and bees love it

Once you’ve evaluated the physical conditions of the chosen site, it’s time to pick the plants based on those conditions and the pollinators that you want to support. My recommendation is that you choose your plants based on no less than 4 points: light requirements, moisture requirements, appropriately native to your area, and bloom time. If you have a specific pollinator goal (e.g., you want to support Monarch butterflies), then add a 5^th point for that goal.

Silver-spotted skipper on wild bergmot (Monarda fistulosa)

Two of those points need further discussion: appropriately native to your area and bloom time.

Appropriately native – these are plants that you know are native to your area whether it is the Piedmont region or the Coastal Plain or the Mountain eco-systems. These plants evolved with the insects in your area and, in the case of butterflies in search of larval hosts, will likely support what’s flying around. For example, gardeners in the Piedmont aren’t expecting to have the deep south-based Palamedes swallowtail butterfly visit so would not plan to include red bay (Persea borbonia) as one of their host plants. You can research ranges for certain plants using USDA, BONAP, and the Georgia Herbaria.

Bloom time – good pollinator support needs flowers during all 3 seasons: spring, summer, and fall. Luckily, we have a good selection of native plants that bloom in all those seasons. Please don’t forget the fall, especially if you want to support migrating butterflies like Monarchs. They need those flowers to power their trip back to their overwintering locations. Goldenrods, many of which are well-behaved, are an essential part of fall blooms.

Golden ragwort (Packera aurea) is an early bloomer

While I certainly put most of my emphasis on native plants, some non-native flowers are heavy bloomers and might be included as part of the mix in your garden to add extra floral power. These include plants like zinnias, tithonia, and pentas as long as they were grown without pesticides. Other people like to include the non-native herbs parsley and fennel as host plants for Black swallowtail butterflies (note: Black swallowtail is the only butterfly that uses it, not ‘all swallowtails’).

In March of 2014, I published a blog with 3 full lists of seasonal native plants for North Georgia. Here is the blog if you want to read it, or use these direct links to the 3 lists:

Spring

Summer

Fall

Here’s an example of a plant that I would choose for my garden with all 5 points considered: Black-eyed Susan (Rudbeckia hirta) is a full sun, average/dry moisture, native to my area, blooms in summer (late June into early August), and supports small bees and small butterflies.

I hope you are now on your way to evaluating your space and researching your plants. Here are some reference sources for determining host plants for butterflies and moths if you want to support the larval host needs of particular species:

Jaret Daniels’s book ‘Butterflies of Georgia’

David Wagner’s book ‘Caterpillars of Eastern North America’

Butterflies and Moths of North America

North American Butterfly Association/Georgia Chapter

Tiger swallowtail on Asclepias tuberosa

I love it when a plant can do double duty, something mostly unique about native plants. Here a dark Eastern tiger swallowtail butterfly nectars on orange butterflyweed (Asclepias tuberosa) which is the larval host plant for Monarch butterflies.

The next (and last) installment in this series will be about implementation and maintenance; look for that post next week. Link to Part 3.