Defining Common Horticultural Terms, Part 2

We encounter many enthusiastic new gardeners at FloraKansas who have heard about the importance of planting native plants, but don’t yet have the knowledge base needed to establish a successful planting. If you’re dreaming of a flourishing prairie pollinator garden, let me unpack the why behind the what of a few more horticultural terms for you.

Host Plants

Often, the focus for our gardens is on blooms and succession of blooms, more so than host plants.  Beautiful gardens in full bloom are what we see in catalogs, magazine and books. It is natural to gravitate toward these flourishing gardens that nectar-seeking butterflies need to sustain themselves. However, host plants (food for butterfly caterpillars) will keep them coming back to your landscape for years to come.    

It’s important to plan for the entire life cycle of a pollinator. Butterflies need places to lay their eggs.  Think of host plants as the baby nurseries of the garden. Female butterflies will flit and flutter through your garden looking for the right plant to lay their eggs. Some will lay their eggs on stems, or on the underside of leaves, hidden from predators. If you have a variety of host plants, you will attract a variety of butterflies. 

Newly hatched monarch caterpillar on common milkweed (Photo by Brad Guhr)

Ultimately, the goal of any habitat garden is to provide everything those butterfly species need to complete their life cycle. Food for all stages of their life cycle, protection, and water are needed at different times throughout the year. The tiny larvae (caterpillars) will emerge and begin eating on the host plant. As they eat, they grow until they leave the plant and form a chrysalis. It is a fascinating process that you can watch unfold in your own garden. 

Here are a few host plants and the pollinator they attract:

  • Wild Lupine – Karner Blue butterfly
  • Golden alexander – Black Swallowtail butterfly
  • New Jersey Tea – Spring Azure butterfly
  • Columbine – Columbine Duskywing
  • Smooth Blue Aster – Crescent Butterflies
  • Little Bluestem – Leonard’s Skipper
  • Prairie Violet – Fritillary Butterflies
  • Pearly Everlasting – American Lady
  • Milkweeds – Monarchs
  • Paw Paw – Zebra Swallowtail butterfly
Zebra Swallowtail Butterfly on Pawpaw tree at the Arboretum, photo by Janelle Flory Schrock

Resource: Holm, Heather. Pollinators of Native Plants: Attract, Observe, and Identify Pollinators and Beneficial Insects with Native Plants. Pollination Press, 2014.

Sunlight Defined

Knowing how much light you have within your landscape is an important piece to a sound design. By simply watching sun patterns throughout the year, you will be able to determine how much sunlight your garden receives. Industry standards and labeling can then be used to assist in selecting the right plants for your landscape conditions. Here are some terms worth knowing since all plants require sunlight to grow, but differ in the amount and intensity of light needed to prosper. 

  • Full sun – Plants need at least 6 hours of direct sun daily
  • Part sun – Plants thrive with between 3 and 6 hours of direct sun per day
  • Part shade – Plants require between 3 and 6 hours of sun per day, but need protection from intense mid-day sun
  • Full shade – Plants require less than 3 hours of direct sun per day

Full Sun

Not surprisingly, this type of light describes what most prairie plants need. They enjoy open, bright sunny locations with direct sunlight for most of the day. This could also be morning shade/afternoon sun or vice versa, as long as there is at least 6 hours of continuous sunlight. Most of these plants have deeper root systems or adaptations that help them endure this light intensity for the growing season. 

Let experience be your guide when situating plants. Yes, some plants can handle full sun, but need protection for the hot afternoon sun. Or they can handle full sun with consistent moisture. This is the other reason to understand your site, including soil moisture, soil type, root competition and drainage.  All these factors directly affect plants too.  

Sun loving prairie plants

Part Sun and Part Shade

These light definitions are quite a bit different than plants for full sun.  Plants for part sun and part shade obviously require less light, more importantly, the light intensity is a key factor for their endurance and success.  Filtered sun for most of the day or morning sun afternoon shade fit the bill for situating plants.  Too much direct sunlight for too long a period will stunt plants needing part sun or part shade. 

There is often a fine line between getting too much sun that the plants suffer and getting too little light that the plants don’t bloom. For either group, providing direct morning sun is often the best choice.

Full Shade

Most shade plants require anything from the dappled shade found under deciduous trees, indirect light found on the north side of the house or deeper shade found under evergreens. In our area, growing shade plants can be a challenge because we are trying to grow shade plants in what was once a prairie environment with intense full sun. True shade plants often perish because they get too much sun, too much hot dry wind and/or too little moisture.

To successfully grow shade plants in our area, they need protection and consistent moisture. Any shade gardens must mimic the woodland environment. Loamy soils with leaf litter, consistent moisture – but not too much! – and protection from drying winds. It can be a challenge, but shade gardens can be carefully created with the proper light conditions, too.

Dyck Arboretum woodland garden with columbine, woodland phlox, white woodland aster and solomon’s seal

Coneflowers: A Lesson in Host Plants

Coneflowers are so emblematic of the prairie. I love to include these prairie denizens in many of my designs. They are quite adaptable and I love the yellows, purples and pink colors of the true natives as they bloom during the summer.  The new cultivated varieties are attractive too. A mass of coneflowers with little bluestem make a nice combination by providing color and texture through the growing season. But right now, many of the plants are full of little black or brown caterpillars that are using Echinacea and Rudbeckia as their food.

Coneflowers as host plants

We are getting calls from our members and customers, and are seeing damage on our plants as well. Coneflower leaves are blackening, getting holes and disappearing. Contrary to how you may feel, this damage is an indication that your garden is functioning properly. Host plants are the vital food source that caterpillars live on. Adult butterflies will seek out these plants to lay their eggs on because they know that the caterpillar cannot travel far and will not survive if placed on a plant that they cannot eat. These caterpillars will eventually turn into checkerspot butterflies or a relative in that family. 

Think differently about your landscape

One of the goals of any garden – besides beauty – is to have pollinators in your garden. Sometimes they might not immediately be in the form you desire. Sometimes pollinators or their caterpillars may eat your plants or deform them.  Don’t be too hasty to spray or remove the culprits. They are doing what comes naturally to them and it is often better to leave the insect. These insects are fantastic food for fledgling birds as well.

Understand the life cycle

The caterpillars eating your coneflowers will make cocoons in a week or so and then turn into butterflies.  We must learn to embrace these caterpillars and accept some damage. The coneflowers will eventually recover. The tradeoff is that we create habitat suitable for butterflies to complete their life cycle. The “ugly, hairy” caterpillars will morph into beautiful butterflies that are equal to the beauty of the flower. 

The key to a successful butterfly garden is to plant both nectar and host plants, so that the butterflies will have a food source in all stages of their life cycles. We often design our landscapes as nectar sources and forget that these pollinators need host plants too. So as you design your landscape, include flowering plants that produce nectar and also double as host plants.

Other host plants

  • Black Eyed Susan (Rudbeckia hirta) Host plant for: Silvery Checkerspot, Gorgone Checkerspot, Bordered Patch butterfly
  • Aster spp. Host plant for: Pearl crescent, Painted Lady and more
  • Coneflower (Echinacea spp.) Host Plant for: Silvery Checkerspot and more
  • Hollyhock (Alcea spp.) Host plant for: Painted Lady, Common Checkered-Skipper and more
  • Golden Alexander (Zizia aurea) or Dill (Antheum graveolens) Host plant for: Black Swallowtail, Anise Swallowtail and more NOTE: The Black Swallowtail will feed on any plants within the Parsley family.
  • Sunflower (Helianthus spp.) Host plant for: Silvery Checkerspot, Painted Lady and more
  • Milkweeds (Asclepias spp.) Host plant for: Monarch
  • Mallow (Malva spp.) Host plant for: Common Checkered-Skipper, Gray Hairstreak , Painted Lady and more
  • Violet (Viola spp.) Host plant for: Great Spangled Fritillary, Variegated Fritillary, Meadow Fritillary and more

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.

Insects: The little things that run the world

They pollinate 90% of the flowering plants on earth; and they eat plants, the crucial first step in changing plant energy into the fats and proteins that feed hosts of other animals. In so doing, insects sustain Earth’s ecosystems.  They truly are, in E.O. Wilson’s words, “The little things that run the world.”

Yet globally, insect populations have declined by 47% since 1974, a loss that translates into a decline in the very ecosystems that sustain all life on earth, humans included! 

https://www.audubon.org/news/yards-non-native-plants-create-food-deserts-bugs-and-birds

What can be done to reverse this trend? By restoring native plant communities in yards and gardens, we can help reverse insect losses and restore ecosystem health to our yards and gardens. 

Why native plants? In study after study, it has been shown that native plants host many times more insect species than do non-natives. 

Which insect groups are most important? In Nature’s Best Hope, author Doug Tallamy suggests selecting native plants that support two important insect groups: large, nutritious insects (think caterpillars of butterflies and moths) and bees. Caterpillars are the mainstay of most bird diets; and native bees perform the lion’s share of pollination. 

https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/halictid_bees.shtml 

Where can I find resources for host plants native to my area?

Planting a diversity of native plants chosen for their ability to provide food for caterpillars and flowers for nectaring bees, ensures not only a prairie garden filled with a diversity of insects and birds, but also a garden that contributes to a healthier environment. And it is all happening right outside our door! 

Reference: 

Tallamy, Douglas W.  2019. Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard. Portland, Oregon: Timber Press.

Butterflies in the Greenhouse

One of the best parts about my job is working in the greenhouse. Yes, it is usually hot and humid in there, and yes my feet are always wet. But none of that seems to matter when I am surrounded by butterflies! With little wind and lots of native blooms, the greenhouse attracts butterflies of all shapes and sizes.

Viceroy butterfly (Limenitis archippus) on Agastache ‘Blue Boa’
Queen butterfly on Agastache ‘Blue Boa’

Anise Hyssop

In the greenhouse and in the garden, Agastache (aka anise hyssop or hummingbird mint) is a fan favorite for butterflies, bees and wasps. Sometimes they are so full of pollinators I don’t want to water and disturb them! ‘Blue Boa’ is a great garden variety, and grows best in hot sun and well drained soil. Agastache foeniculum is better for less formal spaces, as it tends to spread readily by seed.

Grey hairstreak (Strymon melinus) resting on my thumb; my favorite butterfly! It may be small, but the contrast of orange and grey make this one unforgettable.
Bordered patch butterfly, Chlosyne lacini

Will Sweat for Butterflies

While working in the greenhouse during the summer months, it isn’t hard to break a sweat. Butterflies will occasionally land on my skin and get a taste of the water-soluble minerals in my perspiration, giving me a great opportunity for up-close viewing and sometimes even a photo. Remember to avoid touching their wings when handling butterflies; this can damage the delicate scales and structures that allow them to fly.

Monarch (Danaus plexipus) sipping on some Verbena canadensis

If you want more butterflies in your life, consider planting a native pollinator garden. (Order one of our Pollinator Nectar Garden Kits for curbside pickup HERE.) If you don’t have the time or the yard space, find a natural space or Monarch Waystation near your home where native plants grow and plan a visit!

Rethinking Garden Clean Up

It may not feel like fall yet, but it is coming.  I am ready for some cooler north winds to blow and the leaves to begin changing on the trees. In the back of my mind, I am grudgingly starting to think about garden clean up.

Things are winding down in the garden, except for the asters.  ‘Raydon’s Favorite’ aster, New England asters and ‘October Skies’ aster are a bright spot in the October prairie garden. Pollinators are covering these nectar rich flowers during the warm afternoons. It is fun to watch so many happy pollinators in the garden.  The grasses are spectacular this year too.   

Monarch on New England Aster

Soon these flowers will fade and the growing season will officially come to an end. The grasses that are so beautiful now will blend into the landscape.  It will be time for the prairie to sleep.  Before we settle in for the winter, there are a few things to take care of in the garden so that it’s ready for next spring.

Taking stock

I know we don’t want to think too much about the landscape, but if you don’t take a few notes now, you will forget by spring.  I know that will happen to me, so I like to spend a few moments reflecting on what has worked and what didn’t in the gardens. 

Do I need to add a few plants to fill or augment my current design? Should I move some plants to make them happier? I take note of plants that need to be divided and/or moved next February or March.  What areas am I going to focus on next year?  Do some of my trees and shrubs need pruning?  What plants have I seen that I believe would work well in the landscape?  What do I need to do to create habitat for wildlife? 

Fall is also a great time to appreciate what you have accomplished.  Even a few steps toward a more sustainable landscape should be recognized.  Your project may not be complete, but you can see progress.  Give yourself a pat on the back.  Your stewardship efforts are making a difference.  Hopefully, you know this and have seen evidence of it in your garden. 

Perennials

We have been rethinking how, when and why we do cleanup of our perennial beds.  It is generally better to leave perennials such as wildflowers and grasses as they are through the winter. The forms and textures of plants such as little bluestem and switchgrass provide movement in the garden and should be left standing. The dark seed heads and stems look great with a back drop of little bluestem.  Enjoy these autumnal combinations. 

Little Bluestem

Wait! Don’t clean up your garden too early.  Cleaning up beds often removes natural food and shelter that wildlife need to survive the winter months.   Coneflowers, black-eyed susans and coreopsis are important seed sources for birds.  Many pollinators and other insects overwinter in stems and tufts of grass in the landscape.  By prematurely removing all dead vegetation you are removing overwintering wildlife.  We have found that it is better to cut these plants down in February and March, but leave the stems in the garden as mulch.  Overwintering pollinators and insects hatch in the spring and these composted plants are a fantastic mulch that add nutrients back to the soil.  In our experience, overzealous cleaning often does more harm than good. 

Leaves

I love the fall color of the trees in October. However, once the leaves have fallen, what should be done with them? I purposely don’t remove some leaves in perennial beds so they can insulate the plants. Keep in mind that too many leaves or larger leaves tend to cake up and seal off the soil. This will keep the soil too wet through the winter for many perennials.

When you are dealing with large quantities of leaves you may need to remove them or shred them so they break down quickly. In a shade garden, they are perfect as mulch. Just don’t let them get too thick that they smother out your woodland plants, too. Remove leaves from your turf areas, but don’t haul them away.  They make great compost that can be used in your garden or flower beds.   

Tablerock Sugar Maple

Trees

This is the worst time of the year to prune trees. Trees are going dormant and pruning now will encourage new growth that will not get hardened off before cold weather. It is better to take note of trees that need pruning and remove suckers or limbs when the trees are completely dormant in November through January. Pruning now will only weaken the tree and reduce its winter hardiness.

Spring seems like it is so far away, but it will be here before we know it. By doing a few simple tasks in your garden this fall, you will save yourself time and effort next season. Why not put your garden properly to bed this fall so you can enjoy it more next year? It will be worth your time.

Planting for Pollinators

One of the hottest trends in horticulture is planting for pollinators.  In tending our gardens, we all want to do our part to make it easier for butterflies, bees, and other winged friends to find the plants they need for survival. 

September is a great time to plant wildflowers.  If you keep pollinators in mind as you plant, they will come.  Try a few of these summer and late-season wildflowers in your landscape.  They are pollinator-magnets. 

Rigid Goldenrod

Goldenrods get a bad rap.  They don’t cause hay fever.  However, they do attract all sorts of wildlife to their bright yellow flowers in late summer.

Rigid Goldenrod with Cheyenne Sky Switchgrass

Aromatic Aster ‘Raydon’s Favorite’ and ‘October Skies’

This is one of my favorite asters.  They each have nice lavender flowers in late-September into October.  These plants are abuzz with activity as pollinators seek the last sips of nectar before migrating or hibernating for the winter. 

“October Skies” aromatic aster

Swamp Milkweed

This milkweed is vital to monarchs as they migrate back south to Mexico.  The pink blooms appear at the right time to provide the energy they need to complete their journey. 

Monarch on swamp milkweed. Photo by Brad Guhr

New England Aster

This wildflower prefers a medium to moist soil.  The dark purple to pink flowers attract tremendous diversity of pollinators to the flowers in fall.  I like variety ‘Purple Dome’ with its shorter habit and dark purple flowers. 

Painted Lady butterfly on a New England aster

Coneflowers

There are so many varieties of coneflowers.  I love the new colors but have really come to appreciate the true native species Narrow-leaf coneflower, Pale purple coneflower, Yellow purple coneflower and Purple coneflower.  The rounded cones make perfect landing pads for all sorts of insects searching for pollen.   

Photo by Emily Weaver.

Black-eyed Susan

This easy to grow wildflower is one of the best pollinator plants.  The yellow flowers with the dark center attract a host of pollinators in including Great Spangled Fritillary. 

Rudbeckia ‘American Gold Rush’ Photo courtesy of Walters Gardens, Inc.

Liatris mucronata

Dotted gayfeather is blooming right now in the arboretum.  The lavender spikes lay lower to the ground than other taller forms but these late season wildflowers are still attractive to bees and butterflies of all shapes and sizes.   

Native Grasses

Don’t forget the native grasses.  Many pollinators overwinter in clumps of grasses such as little bluestem and switchgrass.  Besides their beautiful fall color, these denizens of the prairie provide great texture and structure in the winter garden, too.

Aster ‘October Skies’ with the dark purple blooms of ‘Purple Dome’ aster with a backdrop of little bluestem

Caterpillar Mania – Part I

This time of year is great for caterpillar hunting. I have been finding lots of amazing, colorful critters munching away on the foliage here at Dyck Arboretum. I am always eager to get a picture of them, if I can, so that I can properly identify them later using guides and help from the internet. In doing so, I become engrossed in their beautiful and strange anatomies – spots, stripes, horns, hairs and amazingly grippy legs. There is much to know and discover!

I get close up photos of insects on my phone using a clip on macro lens. By doing so I can see the tiny details on this white-lined sphinx moth caterpillar (Hyles lineata), like the yellow tips on his legs and the white spots on his head.

Caterpillars vs Worms

When a child sees a caterpillar, they might be tempted to point and say “Oooh, worm!”. But we must remember that caterpillars are not worms, they are larvae. Larvae is the immature form of an insect. A true worm, such as an earthworm, isn’t an immature form of anything. There are several other easy to notice differences:

  • Worms do not move on legs – Caterpillars do
  • Worms are not insects, and do not metamorphose into insects – Caterpillars change into an adult butterfly or moth
  • Worms can be microscopic or gigantic, up to 180 ft long!  – Caterpillars are visible, but not larger than 12cm

Also, caterpillars often sport wacky colors and patterns while most of the world’s worms are much more inconspicuous. Earthworms and some marine worms, roundworms, and tapeworms are usually sporting brown or tan skin. However, many types of ocean dwelling flatworms are incredibly colorful, though you won’t likely confuse these guys for caterpillars.

An adult black swallowtail caterpillar feeding on Zizia in our greenhouse. These swallowtails can only feed on plants in the Parsley/Carrot family.

This black swallowtail caterpillar is in one of its early ‘instars’ or phases of development. It will shed its skin as it gets bigger, and coloration changes during this process as well. In the top left, you can see a black swallowtail caterpillar farther along in its development.

Hairy and Scary

Caterpillars are genius defense players. They are so packed full of protein and delicious to predators, they have had to evolve many ways to protect themselves. Some caterpillars, like the monarch butterfly, make themselves taste bad by eating milkweed leaves with toxins in them. Others try to look intimidating with aposematic coloration – body patterns and colors that warn predators to stay back! And some, like the spicebush swallowtail, even grow fake eye spots on their bodies to fool their hunters into thinking they are snakes. My personal favorites are the hairy ones. Caterpillars will sometimes grow hairs to make them hard or unpleasant to swallow. What bird wants a mouth full of hair anyways? Sometimes these hairs are designed to fall off and lodge in the skin/mucus membrane of whatever is disturbing it, causing an itchy rash in some people.

 

This is a cycnia moth caterpillar feeding on Asclepias sullivantii in our plant nursery. This little guy needs milkweed just as much as the monarchs, but doesn’t get the same press for some reason. I made sure not to touch him because of all those potentially itch-inducing hairs!

In part II of this topic, I will talk a little bit about the specific parts of their body, special caterpillar diets, silk making abilities, and how you can design your very own caterpillar-attracting butterfly garden. Until then, keep a lookout for these special critters and do a little discovering of your own!






A New Way to Think About Spring Garden Clean Up

This time of year, we get excited about heading outside for some spring garden clean up. The warmer weather signals that spring in just around the corner. All of last year’s plants, including grasses, perennials and the mountains of leaves blown into the garden, have to be cut down and hauled away, or do they? There is so much to do, but before you clear cut the garden, look closely at what you are removing from your landscape.

Through winter, your garden has provided habitat for many different beneficial insects and wildlife. By removing everything above ground, you are removing nesting sites and the homes of the pollinators you have attracted to your yard. All the old stalks, stems and leaves have protected and sheltered these insects through the coldest weather. So how can you save them and still get your garden ready for spring? Here are some suggestions that will save most of the beneficial insects hibernating in your garden.

Coneflowers and Little Bluestem offer great winter cover for pollinators and beneficial insects.

Carefully remove old growth

Most native bees are solitary creatures that overwinter in the ground or in hollow stems of perennial and grasses. Because they make their winter homes in some of the stems of your plants, cutting these plants to the ground will remove their nesting habitat.

An alternative would be to cut them down to 18 inches now, remove the upper portion and spread it loosely along the edges of your garden or property. Then you can go back when temperatures are consistently above 50 degrees and completely remove the rest down to the new growth at the base. By that time the bees and beneficial insects will have emerged from their winter slumber.

Another option would be to remove the stalks completely just like you have done in past years. I would then bundle the stems together loosely and hang them along the fence or tree line. From there, the insects can emerge and fly to your garden area.

I didn’t realize how many of these stems and stalks harbored the beneficial insects I want in my garden. It is important that we allow the life cycle of these insects to reach completion. I want to encourage you to be patient and careful when you cut down and remove the old growth from your garden. Either keep those plants up longer into the spring or keep them somewhere in your garden so the pollinators and beneficial insects can come out and stay in your neighborhood.

Strategically clean up leaves

We all have piles of leaves that have accumulated over the winter in our gardens. Just like the hollow stems of perennials, leaves protect beneficial insects, including ladybugs, damsel bugs, and butterflies like commas, morning cloaks and question marks through the winter. Other pollinators overwinter as eggs or pupae in leaves. Holding off leaf removal until daytime temperatures are consistently above 50 degrees will favor the hatching of a new brood of beneficial insects to begin their lives in your garden.

Solomon’s Seal surrounded by leaf litter that protects pollinators and insulates the plants for winter.

This simple and thoughtful approach to spring clean up will have a positive impact on the overall health of your garden. Instead of clearing your garden of beneficial insects, you will be connecting your garden with the complete life cycle of these pollinators. Your garden can have a positive impact on the plight of these endangered species. It will be a landscape that supports the pollinators and beneficial insects we enjoy and need so much.






Are Bulbs Good for Pollinators?

My volunteers and I have been spending many hours this fall planting daffodils and tulips around the Arboretum grounds. All told, we will have nearly 800 new blooming bulbs coming up next spring, down a bit from the 1000 we planted last year.

One afternoon my colleague Brad Guhr posed an important question:
“Are bulbs useful to spring pollinators?”

We all love the aesthetics of fat yellow daffodils and spritely crocus, but I had never considered whether they served an ecological purpose. Supposing (incorrectly) that most bulbs I order are native to the Netherlands, what good would they be to our local pollinator population?
I have now been down the rabbit hole of research and will summarize here how bulbs affect pollinators, which bulbs attract them and proper bulb planting technique.

Tulip humilis (aucheriana) is a wild-type tulip that does well in gardens and meadows alike.
By Bernd Haynold – selbst fotografiert – own picture, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4767022

Bulbs and Bugs

Long before people started admiring their blooms, most of our favorite bulb flowers were being visited by pollinators. Such is not the case for today: modern hybrids selected for the biggest bloom and brightest color sometimes become less useful to pollinators. Flowers that have been distorted too far from their original form may have less nectar or be entirely sterile, rendering them useless as a food source. Hybridization can also sacrifice the flower’s strong scent, leaving aroma-sensing pollinators (like nocturnal moths) lost without lunch. As humans try to improve flowers for our own eye, we  inadvertently disrupt their role in nature. Insects and flowers have an important relationship directly related to the flower’s form. If it changes drastically, certain insects may no longer be able to reach the nectar. Because of this, avoid buying highly modified ‘double’ and ‘triple’ bloomers or extra-petaled flowers that will likely inhibit a pollinator’s ability to feed.

Narcissus poeticus, Public Domain, https://commons.wikimedia.org/w/index.php?curid=907

Best Bulbs

Though we may associate the bulb trade with Holland, the native range of daffodils is the Iberian Peninsula and tulips grow wild in Turkey and Central Asia. Crocus were originally native to southern Europe, the Middle East and western China. There are some bulbs native to North America, such as Claytonia virginica and Mertensia virginica as well as the trout lily, but they are too often upstaged by fancy exotics. This link offers great options for North American native bulbs that will benefit you and the ecosystem. If you aren’t ready to give up your tulips and daffodils, never fear! By choosing unhybridized species, the flower retains its pollen and nectar, supplying much needed early spring feeding for hungry pollinators. Crocus, species-variety Tulips and Muscari all are well-loved by hungry bees waking up from their long hibernation as well as wild type daffodils such as Narcissus poeticus or N. jonquilla.

A bee visiting a purple crocus flower.
CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=660234

Claytonia is a lovely North American native. By Dcrjsr (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

Planting Tips

The first step to proper planting is identification – is what you are holding truly a bulb? Corms, tubers, rhizomes and true bulbs all fall under the category “geophyte” (a perennial that stores its food underground). Many rhizomes would not like to be buried as deep as a bulb but corms can be treated much the same. Sorting out the technicalities will ensure correct planting and big blooms!
When planting true bulbs, depth is essential. In general, plant bulbs 2 or 3 times as deep as its height. Example: a 2 inch tall daffodil bulb should be planted 6 inches deep. Digging too shallow is better than planting too deep since many bulbs have contractile roots. Over time, these specialized roots will pull it down to optimal depth. Planting root side down/pointed side up is always best, but if the bulbs are too odd-shaped to tell, plant them sideways to be safe. Thanks to geotropism, a plant’s ability to sense gravity and grow accordingly, they will eventually right themselves.

Bees love Fritillaria meleagris, a dainty and unique bulb native to Europe. By Пономарьова Алевтина (Own work) [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

So, after much scouring of the internet it seems there is no straightforward answer to Brad’s question. Many highly hybridized bulbs do not benefit pollinators, but other heirloom or species varieties certainly do. To benefit early spring pollinators in your bulb garden, install a few North American species or try to find unhybridized varieties that retain their full species name and their ecological importance. Get out your sweaters and garden gloves, now is the time to get digging!