Insects – Motivation for Native Landscaping

Early September blooming plants are attracting loads of nectar-sipping insects right now. Host plants are green and thriving from timely rains and providing food for munching larvae. All this insect activity has led to great enjoyment for me in exploring the Dyck Arboretum grounds and my home landscape. It has prompted me to think more about my real motivation for landscaping with native plants.

Gulf fritillary nectaring on prairie dock

Plants or Insects?

For many years, I’ve claimed that my enjoyment of native landscaping was motivated by my love of plants. Indeed, their flowers, seed pods, seeds, seed dispersal mechanisms, and roots are all interesting traits and worthy of appeal. Getting to know their growth habits, moisture and light preferences all translate to the level of success I will have (or not) in establishing these plants in a given landscape. And early in their establishment, my focus is geared toward making sure they stay alive with my watering, mulching, and weeding efforts.

Common milkweed wind-blown seed dispersal mechanisms are cool to observe. But I am increasingly interested by the insects this plant attracts too (like the milkweed bug)

But as these long-lived perennials develop substantial root systems, become established, and begin to flower, I worry less about their survival. My perspective changes, turns towards what they can do for the local ecosystem. New questions arise. What insects are attracted to their flower nectar? Which insects are pollinating them and leading to seed production? What insect larvae are eating their leaves or other parts of the plant? What predators are in turn feeding on those insects?

Simple image of a prairie food pyramid (Credit: Mariana Ruiz Villarreal (LadyofHats) for CK-12 Foundation)

Plants, being at the base of the food pyramid, dictate the level of diversity that exists further up the pyramid of consumption. Small bases lead to small pyramids and bigger bases lead to bigger pyramids. So in theory, the more different species of plants I install in my landscape, the more species of insects I will host. I can specifically predict what insects I will attract to a landscape based on the larval host plants I establish. For example, milkweed species will draw in monarch butterflies. Golden alexander or other species in the parsley family will draw in black swallowtail butterflies. Willow species will draw in viceroy butterflies, and so on. HERE is a list of butterfly larval host plants.

The Insects Have It

When I stop and think about it, the most interesting parts of tours at the Arboretum are when insects are visible and busy doing their thing. Stopping with a group to watch a hatch of caterpillars devour a plant leaf and dream of what those caterpillars will turn into is pretty cool. Observing a huddle of school kids dump out a sweep net and squeal with delight at finding the baby praying mantis, massive grasshopper, or whatever other interesting insect they are not used to seeing, simply makes my day.

Milkweed tussock moth larvae feeding on common milkweed
Tour participants observing monarch caterpillars and milkweed longhorn beetles on common milkweed
3rd Graders investigating the contents of an insect sweep net

Many of the species blooming now around the Visitor Center at Dyck Arboretum are sometimes considered invasive and perhaps even uninteresting because they are common. But as I highlight in another blog post Finding Value in the Undesirables, they attract a load of insects which makes them interesting to me. Here is a collection of photos of insects taken just outside my office last week:

One particular plant, Leavenworth eryngo (Eryngium leavenworthii), is stunning due to its vibrant color and interestingly shaped features. It’s often noticed by visitors walking to the greenhouse during FloraKansas: Fall Native Plant Days. However, what most people say when they see it is “did you see the swarms of insects on that plant?!” Customers are eager to recreate such insect habitat at their homes. For this reason, I keep a bag of seed for this annual species collected from the previous year to give away.

Become An Insect Promoter

This subtitle may make many traditional gardeners cringe. I have recently followed social media groups of gardeners where the anti-insect sentiment is rabid. Pesticides are commonly recommended to get rid of insect hatches in home landscapes and the recoil response related to spiders in general can be disturbing. Even many of our dedicated members that love to buy native plants for their landscapes don’t like to see the plants they come to love devoured by caterpillars. I am on a mission to change that.

So, if you are not already an entomology enthusiast and in awe of insects, I encourage you to take on a popular motivation for landscaping with native plants. Become more open to welcoming insects. Choose native plants or native cultivars not only because you think they will be pretty, but for how they will eventually host insects, enhance the food web they support, and increase the wildlife diversity in your landscape.

Keystone Natives for the Food Web: Part 3 – Shrubs

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. 

Rough-leaf dogwood bloom

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
New Jersey Tea, Ceanothus americanus

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.

Keystone Natives for the Food Web, Part 2

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. 

Missouri Black-eyed Susan

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.

Rattlesnake master in full bloom

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.