April is a busy month for a dedicated naturalist in Maryland (and I suppose probably the rest of the Northern Hemisphere). It’s when one can expect to start seeing early spring wildflowers and trees in bloom. It’s amphibian breeding season, so it is an excellent time to find frogs, toads, and salamanders and observe the various stages in their life cycles. Snakes and turtles rouse themselves and begin their ritual basking. Butterflies can be found on the wing with increasing frequency. It’s peak migration for a lot of migratory birds and begins the return of summer residents. For gardeners it’s time to start thinking about prepping beds, pruning, taking those seedlings outside, sowing, weeding… the list goes on. It rains a lot – and often unexpectedly – but it’s otherwise the perfect time to be outside.
It’s still winter, but in mid-February it’s already about time to start planting some seeds. I couldn’t be more excited to get started on my butterfly garden’s third year. I’ll be digging new beds, prepping some annuals to add color and beef up the variety, and starting a few new perennials as well. Now seems like as good a time as any to recap the process so far and talk about the ways I hope to improve on the garden for 2017.
2015 saw a modest beginning to the garden. Some of the plants flourished and by summer I had a few lepidopteran visitors, but there wasn’t a ton of activity. I’m sure part of that is due to nature needing some time to adjust to the presence of my little island of native plants, but part of the problem was certainly also due to my rookie mistakes. I started with some common milkweed (Asclepias syriaca) and tried some butterfly milkweed (A. tuberosa) as well but didn’t plant enough of the former and had no success growing the latter. My New England aster and golden alexander (Zizia aurea) did not really thrive, neither making it much past seedling stage. I left the Japanese honeysuckle the previous owner had allowed to grow up the fence, and this attracted hummingbirds to the yard but not butterflies (that I spotted, anyway). Partridge pea, bee balm, and green coneflower (Rudbeckia laciniata) were really the stars that first year, alongside a couple of nice sunflowers. It was a nice start, and by June it added some significant beauty to the yard, but hindsight tells me it had a long way to go.
Last year was a lot more rewarding, with the wildlife seeming to explode into the yard from April all the way through October (as discussed in my first post about the garden). Of course, most notable were the butterflies and moths. I also started to see other insects I hadn’t before in great number and variety: beetles, flies, bees, mantises and more. I found a cool-looking green crab spider hiding in the coneflower and welcomed some small orb-weavers as well. I had a visit from a juvenile gray treefrog, and the number and variety of birds visiting my yard has already begun to increase. So what did I learn or accidentally do differently to see such a dramatic difference?
Lesson 1: More!
This lesson applied to everything: more space, more plant variety, more of each plant, more maintenance. It was great to establish some native plants in the garden, but one or two per species isn’t really enough to support a solid population of butterflies or attract them in enough numbers to make a difference. That said, the greater the plant diversity the greater the animal diversity will become. The only way to achieve both is to expand the physical space of the garden and that in turn requires more time and energy. The payoff has been well worth it. I guess one last “more” is more non-plant features. I’ve added a home-made puddler and a bench and expanded the rock pile, with more little changes to come.
Lesson 2: Barriers
Full disclosure: it was mostly the dogs who taught me this lesson. I put up a small fence within our existing fence to stop them from a) shitting in the garden and b) digging up my plants. It’s also helped with the deer. I have bird netting up to keep them out of the back yard, but that doesn’t always stop them. However, since I put up the inner fence I’ve seen no evidence of them breaching that second perimeter. I caught some eating whatever sunflower and morning glory leaves and flowers grew up over the fence, but last year that was the extent of it. In this immediate area, that is a major and hard-won victory.
Lesson 3: Go Natural, Go Native
This was the general intent all along, but it took some doing to fully implement. For example, there was a massive quantity of Japanese honeysuckle in the back corner when we bought the house. It was pretty, and smelled nice, but it’s an invasive species that’s ridiculously hard to control. So throughout the second year I systematically and with prejudice removed it. It did do a good job attracting hummingbirds to the yard, and after I took it down I hardly saw any, even at my feeder. But it did virtually nothing else except try to choke out my plants, my fence, my neighbor’s trees, the dogs, and the universe at large. In late 2015 we had to have a dead tree taken down, and that gifted me with an abundance of natural wood. I made a large bench (mostly) from it, and used more of it to border our fences and for benches around our fire ring (not inside the garden, but nearby). I used bark and twigs mostly from that tree as natural mulch underneath the bench and it has performed better than I’d hoped. By collecting leaves in the fall I’ve been able to mostly replace purchased straw as a winter cover for the beds.
Lesson 4: What’s a Weed?
The last thing I’ve picked up is how to tell a seedling weed from a desired plant. Of course, part of this is marking and remembering where you planted but it’s not quite that simple. Some perennials like to move around, and often one will find volunteer annuals coming up. I don’t know that I can really teach this skill – it’s just something I’ve picked up. I suppose it starts by learning the most common weeds in your area: for me ground ivy and garlic mustard are two big ones. The other side of the coin is to recognize the seedlings of the species you want. This is easier than you might think, and this way you can safely discard something you don’t recognize. That said, I’ll leave a lot of native “weeds” like violets, dandelions, and clovers alone where I can. I tend not to pull something until I have a fairly good idea what it is, unless the plants around it are particularly sensitive to the wrong neighbors.
With all of that said, what do I want to do with the garden this year? Well, it starts with lesson 1: more! I already dug some more beds in the late summer and fall of last year, and will begin digging more within the next week or so. Eventually the goal is to have no lawn within the fence I’ve put up, but I don’t think that will be doable in one more year. I’ll fill the space I do clear with more of a few existing plants (milkweeds, joe-pye weed, and purple coneflowers, in particular) and some new plants as well. I’d like to go big for some of the new plants – bushes like viburnums and/or buttonbush. I may also try adding some Dutchman’s pipes, though I hear they come with a foul odor. If I feel ambitious I may build a butterfly house from some of that remaining natural wood. I certainly plan to add a fruit feeder (haven’t settled on bought vs. home-made). I look forward to sharing the results.
The eastern tiger swallowtail (Papilio glaucus) is quite common in our region. It’s no less beautiful for its abundance. These beauties can be seen in virtually any meadow, stream bed, or other open area from Spring through early Fall. They are one of the more photogenic butterflies because of their size, coloration, and relatively relaxed movement. Along with the cabbage white, they are some of the most frequent visitors to my butterfly garden.
I recall referring to them decades ago as “yellow swallowtails” as distinguished from “black swallowtails.” I’m not sure if this was a regional colloquialism or my own failing; either way it’s confusing. The eastern tiger swallowtail has both a yellow and a black morph, and several local species of swallowtail are predominantly black. Black swallowtail is actually the common name of one of them. In parts of the Mid-Atlantic, it overlaps with the similar Appalachian tiger swallowtail (Papilio appalachiensis) and the giant swallowtail (Papilio cresphontes). The latter is fairly easy to identify by multiple characteristics, including its giantry. The former is a bit tricky and requires close observation of the trailing edge of the ventral forewing. The row of yellow dots found on the eastern is more of a continuous bar on the Appalachian.
Host plants include a variety of trees and bushes: tulip poplar, common lilac, black cherry, and species of ash and willow, for example. Many of these are common in the mid-Atlantic both as naturally occurring plants and as native ornamentals.
The adults will feed on just about any plant for nectar. I frequently find them on my butterfly bushes (my one non-native concession inside the butterfly garden) and they seem to love buttonbush (Cephalanthus occidentalis) as well. I’ve also seen them feeding from coneflowers, bee balm, thistles, Queen Anne’s Lace, and more. They seem willing to give a chance to any flower large enough to support them while they feed.
Planting a butterfly garden was one of my first landscaping priorities after moving into my home in 2014. On one level, this was motivated by the idea that butterflies are pretty, and it would therefore be cool to see a lot of them often. This is true, and a perfectly fine motivation, but “butterfly garden” is a bit of a misnomer, at least in terms of the endgame. Butterflies (and the other pollinators attracted to the same plants) are hugely important to the ecosystem. Butterfly larvae are a major food source for birds and small mammals – some birds feed almost exclusively on caterpillars of a single species. Increasing local butterfly diversity and population will thus increase the local overall biodiversity and biomass, and sometimes dramatically. It doesn’t have quite the same ring, but I like to think of my garden as a “biodiversity garden.” Some call them “native plant gardens,” or a similar variant. whatever the term, the idea is to support the ecosystem by planting plants that have naturally evolved with other life in the area over millennia.
Designing a butterfly garden, as any garden, begins with deciding what you wish to plant. The goal here is to include mostly native plants that will attract butterflies (and moths and skippers – I probably should be saying “lepidopterans”). Butterflies rely on plants for food during both active stages of their life cycle: the adults feed on nectar and the caterpillars feed on leaves. Like humans, the young of butterflies can range from not picky (generalist) to extremely picky (specialist) eaters. The monarch is the classic example of a specialist – its caterpillars will only feed on milkweeds (Asclepias species). Plants a given species will eat are called “host plants” for the species, and females will only lay their eggs on suitable plants. Adults are typically much more cosmopolitan in their tastes, but feed on nectar. A successful butterfly garden will feature nectar plants to attract the butterflies and host plants to keep them there and propagate them. Of course, many plants serve both purposes, making them ideal choices.
There seems to be some debate regarding the ideal ratio of host plants to nectar plants. My beginner’s take is that it probably doesn’t matter much as long as both are present in significant quantities. However, the more limited the space the more selective one must be. I have hedged my bets a bit by planting as many plants as possible which fill both roles and building around those. Additionally, it’s helpful to consider what is planted elsewhere in your yard and immediate neighborhood. Butterflies after all will not recognize the boundaries of your garden or your property, so plants nearby can also contribute. Many trees and shrubs which may not be practical fits in your butterfly garden space are host plants for a diverse mixture of butterflies and moths. Most common oaks, for example, host hundreds of caterpillar species. Spicebush (Lindera benzoin) is a host plant for the appropriately named spicebush swallowtail. Viburnums host many species and produce lovely white flower clusters.
Aside from plants, a number of other things can encourage butterflies to visit your garden or extend their stay. Many butterflies will feed on overripe fruit, so a suspended tray of fruit can be a nice feature. Some feeders include a sponge soaked in sugary water as well. Butterflies also engage in a behavior called “puddling” to soak up nutrients from wet soil, and providing them with a space to do so can entice them to hang around longer. You can purchase a puddler or make your own, or simply rely on mud puddles. Butterfly houses can also be bought or built as encouragement for your visitors to hang around. Rock piles and/or log piles can serve a similar function (providing shelter from weather and predators). It’s also a good idea to add a place for humans to sit and observe the wildlife; I built a bench from (mostly) natural wood for this purpose.
Much of the source material I turned to when planning my butterfly garden focused pretty extensively on monarchs and milkweeds. It led me to wonder why monarchs in particular get so much of the butterfly press, but the more I think about it the more it makes sense. Monarchs are beautiful, large butterflies that are well known. Because of the viceroy, they’re part of the definitive example of Batesian mimicry. They are also in trouble because milkweeds are in trouble. As I’ve mentioned, their larvae will only eat milkweeds. As one might infer from the name, these plants have long been regarded as, well, weeds. People have been systematically removing milkweeds from a lot of areas, unwittingly endangering monarchs in the process. It isn’t just a problem for monarchs, though. The milkweed tussock moth, small and large milkweed bugs, red milkweed beetle, and other insects all rely heavily on Asclepias. The relationship between milkweeds and monarchs is a very illustrative example, but far from the only example. Adult butterflies will feed on the nectar of non-native flowers, but virtually no non-native plant can host a native caterpillar.
This returns me to the butterfly garden’s true purpose: to contribute ecological functions to the local biosphere. The native host and nectar plants have evolved relationships with many local forms of life on a grand time scale. Restoring these plants to an area also restores those relationships. Alien plants can stand in and provide some of the ecological functions, but not nearly all. I won’t advocate for the complete removal of all non-natives from gardens and other home landscaping, and I make concessions in this area myself. Increasing the number and variety of native plants in one’s yard, though, is a noble goal and a butterfly garden provides an excellent framework for doing so.