Butterfly Garden Plant Profile: Milkweeds

I thought I would try something new, and start profiling each of the plants (or plant groups) in my butterfly garden as a complement to some of the more macro-level discussions I started with. There seems to be no better place to start than with the milkweeds (Asclepias sp.) Plants of this genus are the only hosts for North America’s most iconic butterfly, the monarch. They also attract a wide variety of other insects, for a variety of reasons. Several species are native to the mid-Atlantic, and a few others grow well here. I haven’t found any of these on lists of invasives, so I have chosen to include a sampling of both native and non-native species in my garden. I can confirm anecdotally that monarchs will readily use all as host plants and that many species will take nectar from the natives and non-natives alike.

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common milkweed

Common milkweed (A. syriaca) is a native plant with lovely spheroid clusters of white-and-pink flowers. It can grow 5-6 feet (or more?) tall in good conditions. This is one of the first plants I started in my garden for perhaps obvious reasons. I have seen it in action hosting monarchs, milkweed tiger moths, swamp milkweed leaf beetles, small and large milkweed bugs, red milkweed beetles, and more. Seemingly every pollinator will make a stop at the flowers. It is fairly easy to grow from seed, especially if cold-stratified first. It seems to handle relocation well. This plant will thrive in moist but well-drained soils, but in my experience it will tolerate most conditions. I am always nervous about cutting back plants mid-season, but because monarchs prefer young leaves and breed in Maryland later than milkweeds emerge it is good practice to do so. The milkweeds can handle it.

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swamp milkweed (amid some partridge pea)

Swamp milkweed (A. incarnata) is quite similar. As its name suggests, it does prefer things a little bit wetter. Mine hasn’t taken off quite as well as the common milkweed, but it does return each year. Its flower clusters are smaller and not the same near-spherical shape, but do tend to a brighter pink. The leaves and seed pods are narrower. Other than the wetness, the same plant care notes apply to swamp milkweed. I know it hosts monarchs and the swamp milkweed leaf beetle and I suspect the other insects mentioned above can eat it as well. It’s a great alternative to common milkweed for a wetter space.

Asclepias tuberosa
butterfly weed (with oleander aphid infestation)

I am still trying to establish some butterfly weed (A. tuberosa). I had read that this species can take a little longer than the others to get going, and this is proving true. Butterfly weed has bright orange flowers and clear (as opposed to milky) sap. So far none of my seedlings from previous years has survived – I don’t know if I have been choosing the wrong location, experiencing a run of bad luck, or something else, but I will keep trying. The orange would really be a nice accent to the rest of my garden’s color pallette. It’s also reportedly a great nectar plant for many pollinators, and since biodiversity is my ultimate goal any native plant that fits the host/nectar profile is a plant I want.

The Maryland Biodiversity Project lists nine additional species (plus two subspecies of swamp milkweed) as Maryland natives. Some appear to be quite rare, and others are limited to the coastal plain. The remaining few species are on my list of potentials for future plantings – clasping milkweed (A. amplexicaulis) looks particularly attractive. I’ll have to balance diversifying the milkweeds with filling other niches, though, so they may have to wait in queue for a few years.

I did mention non-natives, and thus far I have tried two of these. Last year I added some bloodflower (A. curassavica), a more southern species that nonetheless grows well here.  I couldn’t resist the striking red-and-yellow flowers or the glossier green of the stems and leaves. I have observed monarch caterpillars munching on this plant and many insects taking its nectar, so I feel vindicated in sneaking in this non-native plant for variety’s sake. This year I am similarly experimenting with “showy” milkweed (A. speciosa), which is from the western half of the continent. I’m not sure if the seedlings survived the deluge we got earlier this month, but if they did I look forward to seeing if these perform as well as the bloodflower.

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Bloodflower

I haven’t had too many problems keeping milkweeds healthy once they’re established. One exception is the occasional infestation of oleander aphids. Perhaps coincidentally they have attacked my swamp milkweed most voraciously. The point of my garden is of course exploitation by animal life, but this non-native aphid does not contribute positively to the ecosystem so I don’t tolerate them. Fortunately they seem fairly easy to control. I have found manual removal to be very effective. I simply squish them by grasping the plant stems and rubbing, then rinse the gross yellow goo with a hose.

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All in all, milkweeds are low-maintenance flowers that add a lot of visual interest to a garden. They check a lot of boxes in terms of ecological niches as well, even excluding their well-documented relationship with monarch butterflies. There’s very little not to like.

Featured Species #5: Monarch

The monarch (Danaus plexippus) is the classic poster child of butterflies, at least in North America. There are plenty of good reasons for this. It’s large and gorgeous. Its annual migratory pattern is a stunning story. Its life cycle is easy to observe and study, making it ideal for classrooms and amateur naturalists alike. The monarch is also an object lesson in conservation, as it has been endangered by a once-systematic elimination of its only host plants (milkweeds). Its lookalike, the viceroy, is the classic example of Batesian mimicry. In short, the monarch is a biology and ecology lesson all neatly wrapped in a beautiful package.

Danaus plexippus (15)

The monarch also just so happens to be the only butterfly species I have documented in my garden through all of its life stages. I have also collected its caterpillars to raise. I learned (or possibly relearned?) the term “instar” by way of the butterfly garden, and had the privilege of viewing monarch caterpillars at each of these stages. If you ask me, the caterpillars are almost as attractive as the adults. It’s pretty astonishing to watch them eat and grow so rapidly from the moment they emerge from their eggs as tiny pinheads of life.

Eggs

Caterpillars, from first to fifth instar

Pupae

Adults

Danaus plexippus (57)

Danaus plexippus (58)

If you want monarchs, all you need do is plant milkweeds (flowers in genus Asclepias). Several species are native and/or do well in the Mid-Atlantic region. I have common milkweed (A. syriaca), butterfly weed (A. tuberosa), swamp milkweed (A. incarnata) and bloodflower (A. curassavica) in my garden. Bloodflower is not native in Maryland, but it  grows well here and the monarchs still eat it. Additional milkweeds for your area can be found here. The fact that “weed” is in the name must be what turns folks off, because it really is an attractive plant available in a variety of colors. Milkweeds support a wide variety of other native insects, as well, so they are an excellent choice for anyone desiring to plant natives.

As picky as the caterpillars are, adult monarchs seem to be pretty gregarious feeders. I have seen them take nectar from the milkweeds as a one-stop shop but also from joe-pye weed, butterfly bush, and zinnias. It seems the best strategy for helping monarchs find your milkweed is to plant a variety of perennials and annuals that flower at different times throughout the summer. With the right mix of plants you can expect to see several generations between their mass migrations. If you want to protect them from predators and watch them through a full life cycle, all you really need is a clear, ventilated box or jar, some sticks, and milkweed leaves.

Danaus plexippus (56)

Monarch Links

Wikipedia
Maryland Biodiversity Project
BugGuide
MonarchWatch

Butterfly Garden Year 3

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.

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About half of the garden in mid-2015

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?

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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.

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Apparently also “More Yellow”

 

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.

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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.

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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.