Center for Pollinator Research, an Interview with Dr. Harland Patch

Dr. Harland Patch is Assistant Professor in the Department of Entomology and Director of Pollinator Programming for The Arboretum at Penn State. He was a key research science advisor in the development of the arboretum's Bird and Pollinator Garden, which opened in 2021. With Joan Jubela, Master Gardener from Wayne County, Dr. Patch discussed the ways he and other stakeholders and scientists are working with the Center for Pollinator Research to understand declines in pollinator populations around the world and address those declines through innovative horticultural practices.

Jubela:  You wear a lot of hats, and it's difficult to decide which area of your expertise to investigate, but I want to focus on gardening. What would you like to say to gardeners in Pennsylvania?

Patch:  Pennsylvania is a special place. Pollinators are doing pretty well in Pennsylvania compared to other parts of the world. We have lots of bees. We have a diversity of bees, a few hundred species, and, of course, butterflies, flies, and other pollinators like the ruby-throated hummingbird.

Interestingly, in Pennsylvania, because it's a forest, we have two seasons for bees. Most people think of the summer to fall season, which is open meadow plants, fields full of flowering plants for pollinators. Our high time of diversity for pollinators and flowering plants is July. Pennsylvania, in the springtime, it is not these open field plants that are important; it's the trees and shrubs. So, we should plant for two seasons, trees and shrubs, which basically go from the very end of winter until the end of May. And if you're lucky, understory flowering plants like Virginia bluebells (Mertensia virginica) or native columbine (Aquilegia canadensis). Then the canopy of trees and shrubs closes, and the rest of the year are the plants most people think about. So here in Pennsylvania, to support pollinators, gardeners should think about both of these two seasons.

Jubela:  Are there two or three top plants that every pollinator garden should have across the Commonwealth?

Patch:  That's a great question. In talks, I focus on how to make a fly garden or how to make a bee garden, and these conclude with plant lists. These lists can be found at the Center for Pollinator Research. We have something called the pocket guides. But if you want to have pollinator diversity, if you want to have bees or flies but also a lot of pollinating wasps and butterflies, then you can't go wrong with the native mints, often called the mountain mints (Pycnanthemum spp.). Everybody knows about garden mints (Mentha spp.), which mostly come from Europe and Asia. We know a lot of pollinators go to those, but our native mints, those attract the greatest number of pollinator species of any plant you can buy. I would add common boneset (Eupatorium perfoliatum), and if you want to attract both bees and flies, then anything in the carrot family (Apiaceae) could also be very attractive to pollinators.

Also, go to the Master Gardener Pollinator Friendly Habitat Certification Program. I've worked very closely with Connie Schmotzer and other Master Gardener leaders to help develop that program, the certification list, and the plant suggestions. It's like one-stop shopping for any gardener. Every garden is an experiment, as you know, but they offer a long list of plants that bloom throughout the seasons. It has all the resources that you need, including information about reducing pesticides and removing invasives. These are big issues.

Jubela: There are lots of tools and resources offered on your website, and I would like some clarification on which of those tools is really meant for gardeners, such as Beescape.

Patch: We work with a lot of different constituencies, including beekeepers, gardeners, and land managers. And we work with landscape architects. They work on a large scale, and so, of course, we try to influence them, and they can become quite sophisticated in the way they create gardens and manage landscapes.

Jubela: Like the beautiful Pollinator and Bird Garden at the Arboretum that Claudia West worked on with you.

Patch: Exactly. It's interesting. Many gardeners know about the New Perennial Movement, Piet Oudolf, and folks like that, the famous designer who did the Highline in NYC. It's always struck me that their flower vocabulary for formal gardens was initially so amenable to pollinators and wildlife generally. Their aesthetic is more bushy and more wild and more natural, but those designers did not create that aesthetic for those reasons for pollinators. It was not until this generation, Claudia's generation, that they really tweaked [their practice] and worked with biologists to create gardens that are both beautiful and support biodiversity. So, at the Center for Pollinator Research, we work with a lot of different kinds of folks. Beescape started off as a beekeeper tool, but it has grown and changed and will continue to change. It will become a tool for gardeners as well.

Jubela: What are some of the projects between gardeners and scientists through the Center for Pollinator Research?

Patch: It's multifarious because we have 40 scientists in the center working on many different levels. We work with beekeepers, many of whom maintain landscapes for their bees. They send us pollen. We have an identification system that DNA barcodes the pollen, and from it we can learn which plants bees are going to.

We also have new AI devices we're working on to monitor pollinators and other insect populations; an example is FloraCount. We're working with Master Gardeners this summer at the flower trials in Manheim. They look at new varieties of plants to see how long they flower and what diseases they get, and such. We've created an app for gardeners and others that we’re piloting at these flower trials. It allows the user to score how attractive a particular variety of plant is to pollinators, and you don’t need very much training to use it.

Jubela: So FloraCount is an app.

Patch: Yes. You must have the patience to sit and watch your flower for 10 minutes. You take a picture of the plant, and it calculates automatically the floral area. That's important. The more flowers a plant has, the more attractive it is to pollinators. For instance, a young plant is not as attractive as an older plant, all things being equal. You also weight FloraCount to the landscape you're in. Obviously, in a habitat like a nature reserve, we will likely have a lot more pollinators than in the parking lot of a big box store. For that, we have models to predict pollinator activity, which is what Beescape does. And so, we're constantly working to improve FloraCount. In fact, the data that gardeners bring to us via the app will help us better improve our models because gardeners will actually be testing these landscapes in the real world.

Jubela: Can we be looking for FloraCount soon?

Patch: Not too far into the future. This is our big summer to do more testing with real people.

Jubela: I've read that, along with other scientists like Dr. Emily Erickson, you have studied what all the elements are in flowers that attract pollinators, elements like scent, color, and access to pollen, and how those essential elements might be bred into cultivars. Can you talk about that research? 

Patch: Yes, we're very interested in that. Emily's work is what led to us creating FloraCount. She sat and observed flowers for so long we were able to construct models on exactly the length of time needed to determine what kinds of insects were drawn to that flower. So, we have been studying cultivars, not native plants, but cultivars derived from native plants are called nativars. We know with the help of the Master Gardeners in Manheim that some nativars were more attractive to the pollinators than the so-called wild-type plants, which we should expect. Imagine a meadow, a natural wild meadow, where the plants of any one species are diverse. They're individuals, and some of these individuals will be slightly more attractive to insects than others. For instance, maybe one flower is producing a little bit more nectar than another. If you go in the field and pull out one of these plants at random to breed, you may not pick out one that's on average more attractive. It could be less attractive. It's not surprising to us that you could find nativars that are more attractive than the average native plant in a wild field.

 Jubela: That's interesting.

Patch: When you take a plant out of the wild, let's say a coneflower, a common plant used in pollinator gardens, they're usually bred to be shorter. Many people don't like super tall plants. The market doesn't. The flowers are bred to be bigger, and they are bred to be different colors, bright red, bright purple, because humans like that.

Jubela: Yes, a lot of people do like those bright colors.

Patch: That changes the plant, but we know from economists that those plants sell for more money because they are more attractive to people. If growers can breed more attractive plants, then we can also breed plants that are maybe more nutritious. Think about it, if you live in an urban place, or any place humans live, an anthropogenic landscape, these tend to be quite poor in flowering plants, so you could plant some super great plants for pollinators that are bred to be for urban landscapes where it's pretty depauperate of diversity and they could be better plants than even if we grew the wild plants. Does that make sense? This is in places that are particularly compromised.

Jubela: Does this go with the idea of how important it is to consider landscape context? Then, potentially, in urban landscapes, you could begin to create little islands of pollinator activity. Is that kind of the notion you're suggesting?

Patch: You've absolutely got it. There has been great urban research on pollinators in this country and particularly in Europe. It's clear that the insects that live in urban areas have changed, like the group of mammals have changed, right. You find things that live around humans—pigeons and English sparrows, whatever. And that's true of the pollinator community. The number or species of pollinators decreased. We should think about urban landscapes as distinct from more wild landscapes. And so, we should work with these landscapes and think about them as they are and not delude ourselves that we're going to return to something in the far past, because we've changed everything.

Jubela:  What are strategies that home gardeners can use to help sustain pollinators?

Patch:  For now, the simple rule is to plant more flowering plants because there are so few; just drive around and look. There are so few, and if you can plant more native plants, more native trees, shrubs, and field plants, that's what you do. And just keep ratcheting all that planting up. Get more people to plant native plants. That's what our goal is.

Jubela: Are there studies that suggest how these conservation and restoration attempts are working? Is the push to engage home gardeners to grow native, is that helping? Do we know, or are we still just kind of hoping and crossing our fingers?

Patch: There have been different kinds of studies in different parts of the world. There are too few. One of the reasons we're creating these AI-type devices is that we need more data from more parts of the landscape. There are not a lot of entomologists; there are not a lot of bee specialists. This is where Master Gardeners come in, those working with our app FloraCount, citizen scientists, and those kinds of projects. We've always liked to work with other folks, but it's becoming increasingly important because we need big data, we need more data from larger areas to really understand what's going on. So, you ask the question, though, are these things working? I can certainly say they're working in the United Kingdom, where there's been a very pronounced, well-documented decline in pollinators over the last two centuries.

During the last 20 years, they have really made efforts, increasing the numbers of flowering plants, putting back forests that didn't exist, for you know, centuries, not millennia, but in places that have been very denuded; they have seen positive effects. The basic principle of just putting in more plants, and more diverse plants, and more flowering plants, it does work, linearly in that the more diversity you put out, the more pollinators you get. That's very encouraging.

Jubela: Thank you, Dr. Hatch.

Patch: You're welcome.