Milkweed for Monarchs

Posted on February 24, 2021 by Brad Guhr

In Kansas and throughout the central U.S. corridor, we need to plant more milkweed for monarchs. Because of human-caused reductions of host plant milkweed species through the monarch migration corridor, this butterfly is in decline. I will summarize the current plight of the monarch, review its life cycle and why it is in decline, and recommend seven milkweed species we should be planting more frequently in our urban landscapes to attempt to aid monarch recovery.

*Monarch on swamp milkweed in the Arboretum greenhouse. Photo by Barbara Beesley.*

Plight of the Monarch

Experts monitor monarch populations by documenting the extent of area they occupy annually in their Mexican oyamel fir forest overwintering sites. While the numbers are variable from year to year, the overall downward trendline seen in the following graph is discouraging.

*World Wildlife Fund monarch data cited in a blog post by Cornell University’s Anurag Agrawal*

The following recent announcement highlights that the monarch warrants protection to stop its decline, but that too many other species needing protection are taking priority at the moment.

Monarch Life Cycle

From March to November, eastern populations of monarchs migrate from Mexico to Southern Canada and back every year. It usually takes four generations of monarchs to make this journey – two going north and two going south.

*Monarch generations over a typical year from Journey North*

Various species of milkweed (Asclepias spp.) throughout the migration corridor of the central U.S. play host to hungry larvae as an essential element of the monarch life cycle.

*Monarch life cycle from the U.S. Department of Agriculture*

Adult butterflies completing the first northern leg of the journey from Mexico to the south central states of the U.S. including Kansas are conditioned to find milkweed plants to lay their eggs in spring. Later generations returning south in late summer are doing the same.

Human Impacts

In a 2013 presentation at Dyck Arboretum, Monarch Watch’s Chip Taylor expressed that a loss of milkweed throughout this migration corridor is one of the top reasons for the monarch’s decline. The advent of no-till agricultural practices has been great for the efficient production of crops, but its broadcast spraying of generalist herbicides like glyphosate (i.e., Roundup) has also been very efficient at killing milkweed throughout the Plains and Midwest.

*Acres converted of prairie converted to cropland in monarch flyway from Monarch Watch*

Loss of monarch nectar sources through habitat destruction, widespread use of insecticides, and climate change pose additional challenges to the monarch.

More Milkweed Needed

The monarch butterfly evolved along with the presence of prairie milkweed species throughout the Great Plains and Midwest during the 10,000 years since the last Ice Age.

*Presettlement extent of prairie from Michigan State University*

Just as humans have rapidly reduced the presence of milkweed in the last couple of decades, we should be able to find ways to re-establish milkweed.

In a recent presentation, I promoted the planting of milkweed for monarchs and highlighted the diversity of 19 milkweed species found in Kansas. These species are well-documented in the book Kansas Wildflowers and Weeds by Michael John Haddock, Craig C. Freeman, and Janét E. Bare. Compiling information from Chip Taylor and a 2018 Iowa study in Frontiers of Ecological Evolution on milkweed preference by monarchs, I landed on promotion of the following seven yellow-highlighted species. With high monarch larvae survivorship, and being relatively easy to establish from plugs, these seven milkweed species are good selections to grow in any sunny garden spot.

To make a dent in the recovering milkweed presence throughout the monarch flyway, seeded milkweed re-establishment should be boosted in large-scale habitat areas like in between agricultural fields, along roadsides and in Conservation Reserve Program land just to name a few. But such efforts will require coordination with governmental agencies and lots of planning. What I will propose with the rest of this post will be what we can each do with our own plots of land. Consider planting plants in native plant gardens and collect and spread seed if you have areas that are larger and less manicured.

The following seven milkweed species offer aesthetically pleasing milkweed species that are good larval hosts for monarchs and good nectar sources for a variety of insects. All milkweed photos are courtesy of Michael John Haddock (Source: Kansas Wildflowers and Grasses Website)

Common milkweed can get to be weedy in the garden, but it is easy to pull, so I don’t mind a little weeding because of the immense benefit this monarch favorite offers (prefers dry to medium soil, grows 4-5′ tall, and blooms in June to July with a very sweet fragrance).

*Whorled milkweed prefers dry to medium soil, grows 1-2′ tall, and blooms in June to July*

*Butterfly milkweed prefers dry to medium soil, grows 1-2′ tall, and blooms in June to July*

*Green antelopehorn milkweed prefers dry to medium soil, grows 1-2′ tall, and blooms in May to June*

*Showy milkweed prefers sandy loam dry to medium soil, grows 3-4′ tall, and blooms in June to July*

Smooth or Sullivant’s milkweed prefers medium to medium -wet soil and can be commonly found in the bottom of roadside ditches. It grows 3-4′ tall, and blooms in June to July. While a bit similar looking to common milkweed, smooth milkweeds differs with its smooth, non-hairy leaves that clasp the stem, and with more flat rather than rounded flower cluster.

*As the name implies, swamp or marsh milkweed likes its feet wet, prefers wet to wet-medium soil like along a pond edge, grows 4-5′ tall, and blooms in August to September*

As tempting as it may be to plant tropical milkweed (Asclepias curassavica) in an annual bed or a pot, try to avoid it. Even though it can host monarch larvae and the flowers are attractive for insects and humans alike. The following article from Xerces Society provides compelling reasons not to plant tropical milkweed in non-tropical areas. Holding monarchs in colder places longer than they should, and exposing monarchs to the protozoan parasite Ophryocystis elektroscirrha (or OE for short) are two of those reasons.

Come check out our Spring FloraKansas Native Plant Festival, April 22-26, 2021. There you will find a wide selection of milkweeds and other wildflowers, grasses, sedges, shrubs, and trees to enhance your landscape for monarchs and all insects!

Keystone Natives for the Food Web: Part 3 – Shrubs

Posted on February 17, 2021 by Scott Vogt

Over the past few weeks, we have been listing native wildflowers that support the food web. Because many species of insects have suffered significant declines, any help we can give them will make a real difference in their life cycles. Our goal should be to provide habitat for the largest possible number of insects, pollinators and other wildlife. On that theme, here is a list of native shrubs to aid the food web.

Prunus

This diverse genus includes: sandhill plum, dwarf sand cherry, chokecherry, plum, and wild plum. These spring blooming shrubs attract many species of insects, and their fruit later in the season is a favorite of wildlife, including birds.

These plants support over 450 Lepidoptera species, including Eastern Tiger Swallowtail, Coral Hairstreak, Striped Hairstreak, Red-spotted Purple, Cecropia moth, Promethea moth, and Hummingbird Clearwing.

*Sandhill plum-Prunus angustifolia Photo courtesy of Craig Freeman*

Not all of these shrubs are garden worthy because of their spreading/suckering root systems and size. My preference would be to relegate many of these to the outskirts of my property so they can comingle with each other and form a nice thicket.

Prunus besseyi ‘Pawnee Buttes’s is a nice small shrub with excellent characteristics.

Side note: The black cherry (Prunus serotina) is a 35-45 foot tree with fragrant, pendulous flowers that burst open in spring, resulting in loads of fruit cherished by wildlife. This is one of the top choices among woody trees for its exceptional support of wildlife.

Dogwoods

Dogwoods support specialist bees, generalist bees and over 100 caterpillars. This too is a diverse genus of varying heights, forms and textures. These spring/summer blooming shrubs or small trees attract aphids, beetles, flies, grasshoppers, sawflies and wasps. The fruit are eaten by birds. Many species form thickets or have dense branching that provides shelter as well.

Of the native species, the Redtwig Dogwood is the most common. Its red and yellow stems stand out in the winter landscape. Cultivars include ‘Cardinal’, ‘Arctic Fire’, Arctic Fire Yellow’, and ‘Winer Flame‘.

Other dogwoods worth mentioning are Cornus amomum ‘Red Rover’, Cornus drummundii (rough-leaf dogwood), and Cornus racemosa.

Flowering Dogwood (Cornus florida) is difficult to grow in our area because most cultivars need acidic soil. They are more common in southeast Kansas and into the Ozarks. If you are lucky enough to see these bloom in the wild you will be awestruck. They are one of the most conspicuous and attractive flowering trees in our area.

Viburnum

Kansas is home to two viburnums, Blackhaw Viburnum (Viburnum prunifolium) and Rusty Blackhaw Viburnum (Viburnum rufidulum). They can be found in the wild, east of Wichita and into southeast Kansas. The creamy-white blooms in the spring attract all sorts of pollinators. Fruit in the late summer into fall is the first choice of birds. These are large shrubs or small trees that ultimately reach 10-12 feet tall and each has attractive fall color.

There are hundreds if not thousands of viburnums and viburnum cultivars. A couple others worth mentioning are ‘Allegheny’ which has semi-evergreen foliage and Viburnum dentatum cultivars (Blue Mufffin, All that Glitters, and All that Glows) with their abundant fruit displays.

Blackhaw Viburnum fruit-*Viburnum prunifolium*

Other shrubs to consider:

New Jersey Tea – Ceanothus americanus
black chokeberry – Aronia melanocarpa
Willows, Salix sp. – (#1 plant supporting bees)
Pussy Willow – Salix discolor
buttonbush – Cephalanthus occidentalis
elderberry – Sambucus canadensis
eastern ninebark – Physocarpus opulifolius
St. Johnswort – Hypericum densiflorum
spicebush Lindera benzoin
swamp rose – Rosa palustris
winterberry – Ilex verticillata
Witch-hazel - Hamamelis virginiana
Inkberry – Ilex glabra
Deciduous holly –Ilex decidua
Winterberry – Ilex verticillata
red chokeberry - Aronia arbutifolia
Fragrant Sumac – Rhus aromatica
Eastern Ninebark – Physocarpus opulifolius
Fringetree – Chionanthus virginicus

Among woody plants, these shrubs will add much diversity to your landscape and attract a diverse set of wildlife. By offering abundant food sources to insect and wildlife throughout the growing season, you will naturally expand what you see in your garden. We must consciously consider plants that fit both the insects’ needs and our longing for garden beauty. We can have the best of both worlds.

Side note: Of all plants studied by Doug Tallamy, he found that oaks support the most caterpillars. Obviously, these are not shrubs, but rather large trees. Oaks must be one of your first choices when considering shade trees for your landscape. Recommended trees of south-central Kansas.

*Mighty Burr Oak ready for spring and all those caterpillars.*

New Plants: Part I

Posted on February 10, 2021 by Katie Schmidt

There are no new plants; they aren’t flying in on a spaceship from a galaxy far, far away. But when it comes to Florakansas Native Plant Festival we try to keep the inventory fresh by always adding new offerings in our inventory. While we always offer the tried and true natives and adaptable we have come to love, we also want to offer a little something *new to you* every year. Sometimes this means finding a source of more obscure natives, or seeding them ourselves. We also work to get our hands on new commercial varieties of garden favorites.

And while February and March can seem long and cold, they also signal that FloraKansas is right around the corner! There is no better time to peruse the Native Plant Guide and get up to speed on all the goodies available.

Here are a few of the stand-outs (part II coming soon):

Geranium ‘Crane Dance’

Plant breeders cultivate most commercial varieties of Geranium from Geranium pratense, a species native to Europe and Asia. But this one, selected for its brilliant red fall foliage, is derived from the native G. maculatum. The blooms are an electric shade of blue.

Buddleia ‘Grand Cascade’

Easy to grow, with a thousand and one varieties, butterfly bush is a long-time garden favorite. ‘Grand Cascade’ boasts the largest blooms of any variety, with some 14″ long and as thick as my arm. It is not native to North America, meaning it is likely useless as a host plant for our invertebrates. But Buddleia is an undeniable favorite nectar source for many pollinators.

Plant your Buddleia near a window or patio to enjoy their sweet scent, and be sure to install true Kansas native plants nearby to complete the ecological garden trifecta: host plants for larval food, nectar for adults, and habitat to shelter and rest.

Thermopsis villosa

*Photo by Bob Gutowski, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons*

Better known as Carolina lupine, Thermopsis villosa is native to woodland clearings in the southern Appalachian mountains. Surprisingly drought tolerant once established, this plant will grace your garden with lemon yellow blooms reminiscent of Baptisia. Because its native range is the eastern US, we can assume it takes a bit more water than our dry, upland prairie species. Place this one in full to part sun, in an area that gets semi-regular watering.

Antennaria dioica ‘Rubra’

*Photo by Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons*

Pussytoes are ubiquitous, native all over the North American continent. In Kansas we most often see Antennaria neglecta, field pussytoes. They are short statured and white-flowered, a favorite for pollinators and a good groundcover, but not a showy garden flower. A. dioica ‘Rubra’ is a nice change of pace — it sports a bright pink bloom that you can’t help but love. Native to Alaska, this species is very cold hardy.

All of these plants and many more will be available at our spring sale. Peruse our Native Plant Guide to get inspired and make your plant list. Dyck Arboretum members may pre-order plants once the 2021 Native Plant Guide is made available. (Later in February.)

The second part of this blog post, New Plants: Part II is coming soon!

Keystone Natives for the Food Web, Part 2

Posted on February 3, 2021 by Scott Vogt

A couple weeks ago, we laid the ground work for enhancing the food web by listing some of the keystone species gardeners should include in their landscapes. When choosing plants to support insects, the foundation of the food web in our gardens, we want to make the most of our space.

Insects are typically not picky when it comes to food sources, but they do have their preferences. Here is an extension of that original list to give you more options to diversify your plantings and support a more robust food web in your habitat garden.

Grasses

Little Bluestem (Schizachyrium scoparium)

This native bunchgrass can be found throughout the Great Plains. It reaches two to three feet tall and prefers a medium to dry well-drained soil. Give it plenty of sunlight for best growth. It is the larval host for many species of butterflies including Ottoe Skipper, Crossline Skipper, Dusted Skipper, and Cobweb Skipper.

‘Twilight Zone’ is a nice cultivar with purple green foliage during the growing season and good fall color.

*Twilight Zone Little Bluestem. Photo courtesy Walter Gardens*

Blue Grama (Bouteloua gracilis)

Blue grama forms dense clumps and is extremely drought tolerant. Use in a sunny spot as a ground cover or mix with buffalograss for an easy-care lawn substitute. The flowers look like tannish eyelashes that are attractive well into winter. There are over 10 butterfly larvae that feed on blue grama, including many skippers, Ottoe, Leonards, and Uncas; but also Mead’s wood nymph and the garita skipperling.

My favorite cultivar of blue grama is ‘Blonde Ambition’. Several birds have been noted feeding on blue grama seed, including grassland sparrows, wrens and wild turkeys.

Blue Grama Blonde Ambition — Blue Grama ‘Blonde Ambition’

Wildflowers

Beardtongue (Penstemon sp.)

To see huge bumble bees crawling into these tubular flowers in the spring is fun to watch. The longer lower lip of the flower makes a perfect landing pad. Many of the species have distinct lines leading to the back of the flower known as nectar guides. These lines act like runway lights, leading pollinators to the back of the flower where the nectar is located.

Penstemons are a diverse species, but some of our native Kansas species like Penstemon cobaea, Penstemon grandiflorus, Penstemon tubaeflorus and Penstemon digitalis put on quite a show in the spring. My favorite penstemon variety is ‘Dark Towers’.

Black-eyed Susan (Rudbeckia sp.)

Black-eyed Susan is one of the most recognizable summer-blooming wildflowers. Its bright yellow flowers explode in the summer and are covered with all sorts of pollinator activity. Bees, flies, butterflies, and beetles feed on their nectar and pollen. The fruiting heads also provide seed for birds over the winter.

Missouri blackeyed susan and Rudbeckia ‘American Gold Rush’ are garden worthy perennials.

Coneflower (Echinacea sp.)

There are so many choices when it comes to coneflowers. Oranges, yellows, reds, greens, pinks and every shade imaginable. The options are endless, but I always try to include some of the true native coneflowers in my designs. Echinacea angustifolia, Echinacea pallida, Echinacea paradoxa and Echinacea purpurea are all pollinator magnets. Be sure to avoid any coneflowers with double blooms. They may look cool, but they do nothing for pollinators, because they either don’t produce nectar or pollen or, because of their double-decker nature, don’t allow bees access to it.

Native bees (bumble bees, sweat, mining and sunflower bees) along with honey bees and butterflies (monarchs, swallowtails, sulfurs, fritillaries and many others) glom onto these summer blooming (May-August) perennials. Coneflowers can be quite adaptable, but most appreciate at least 6 hours of direct sun.

American lady butterfly on purple coneflower at CSFL

Rattlesnake master (Eryngium yuccifolium)

The unique globelike blossoms of rattlesnake master attract many types of small native bees and syrphid (hover) flies. I have seen the tan hollow stems used by overwintering tunnel-nesting bees. Rattlesnake master is the host plant for rattlesnake master borer moth.

Narrow-leaf mountain mint (Pycnanthemum tenuifolium)

As a member of the mint family, narrow-leaf mountain mint has a tendency to spread, but it is a garden worthy wildflower because of the diverse pollinators it attracts. Bees, wasps, moths, ants, flies, beetles and many types of butterflies including Ladies and smaller Fritillaries, Hairstreaks, Blues, Common Buckeyes seek out this plant’s frosty white blooms. It also attracts beneficial insects for biological control of pests.

A few others worth considering

Campanula Bellflower
Cirsium Thistle
Claytonia Spring-beauty
Erythronium Trout-lily
Geranium Cranesbill
Helenium Sneezeweed
Heuchera Coral Bells
Hibiscus Rose-mallow
Monarda Bee Balm
Oenothra Evening Primrose
Packera Groundsel
Polemonium Jacob’s-ladder
Pontederia Pickerel Weed
Potentilla Cinquefoil
Uvularia Bellwort
Verbena Vervain
Viola Violet
Zizia Golden Alexanders

Solution gardening works to solve a problem with your landscape. These lists of plants should be considered first to curb the decline of threatened specialist insects. Our goal should be to provide habitat for the largest possible number of insect species and to support a healthy food web. Having most or all of these keystone species in your landscape will make your landscape part of the solution to reversing drastic declines of pollinators in recent years.