"In every gardener there is a child who believes in The Seed Fairy." 

~Robert Brault

'Tis the season for the annual ritual of pruning back tropical and exotic perennial milkweed plants to mere sticks. Gadzooks, that sounds extreme!

Yup. It is, but beneficial. And the consensus among those in the know are starting to lean strongly towards it being the right thing to do for our Monarch butterflies.

*For those of you who grow Tropical Milkweed or are planning to do so and normally skim through the newsletters, PLEASE take the time to read this post thoroughly. ¡Es muy importante por Monarch butterfly health!

Before we get into pruning, let's inform ourselves why we should. It's increasingly becoming clear that pruning perennial milkweed species in mild winter areas where Monarch butterflies live (especially along coastal overwintering site zones) is imperative to their long term health and population viability. For those that are new to the newsletter within the last year, the question is: "Why?"

Answer: Ophryocystis elektroscirrha, Oe for short. Oe is a parasitic disease affecting Monarch butterflies, which is exacerbated by perennial milkweed plants surviving winter's cold. I don't expect everyone to follow all of the links below, but take for face value the need to prune back exotic perennial milkweeds. 

Below is part of a previous post regarding Tropical Milkweed, also known as Mexican Milkweed, and Oe:


April 4, 2015:

On the continuing saga of Tropical Milkweed and Oe spores:

-monarchbutterflygarden.net

Is Tropical Milkweed Killing Monarch Butterflies?

You be the judge. Personally, I see no reason to castigate A. curassavica for its association of harboring Oe spores more so than native species, and may be causing SoCal, south Texas, and southern Florida races of Monarchs to overwinter in their spring and summer stomping grounds without migrating to traditional Monarch overwintering sites, if these faults are mitigated by following the advice of the article above.

Two opposing views on planting Tropical Milkweed. One is by discovermagazine.com, the other by onearth.org:

Gardeners' Good Intentions Are Killing Monarch Butterflies

Don't Stop Planting Milkweed

From the January 25, 2015 newsletter: 

Continuing on the subject of Oe spores from the previous post, an article by the Monarch joint Venture, titled Q&A about research related to tropical milkweed and monarch parasites gives us more information on the disease, some of the latest research findings, and some tips on how to mitigate the unintentional support and spread of the spores to local Monarch butterfly populations from our well intentioned gardening actions.

 Photo courtesy of University of Georgia, Athens, Georgia

Microscope photo detailing Oe spores found on the body of an adult male butterfly.

From the October 18, 2014 newsletter:

The time is approaching soon that the Mexican Milkweed, also known as Tropical Milkweed (Asclepias currasavica) in the Container Butterfly Garden will be cut down to mere 4 to 6 inch stubs.

"You're kidding: why?!" you may ask. Not to reinvent the wheel, Is Tropical Milkweed Killing Monarch Butterflies - Grow or No Grow? pretty well covers the topic. The container garden is home to Mexican Milkweed, plus several other California and North American native species. These native species are deciduous, meaning they go dormant during the winter when the plant parts above ground die back, only leaving the roots to regenerate new top growth in the spring. This drastically reduces Oe spores that have been wreaking havoc in certain sectors of Monarch Butterfly populations.

Oe infestations are mostly identified with regions of the U.S. where Mexican Milkweed overwinters, meaning, it doesn't die back or go dormant. Hotspots for Oe are found on the west coast strain of Monarchs, and the Florida nonmigratory race that has come into existence due to the large amount of perennial milkweeds now growing there. What is OE? gives a good description of this parasite and why it is so prevalent on the west coast and Florida. Cutting back Asclepias curassavica helps to severely curtail or eliminate Oe spores from overwintering on the leaves of Mexican Milkweed.
 
The best solution to curtailing Oe in our gardens is to only plant native species, but that is not as easily done as said:

• Native milkweeds are not very glamorous in appearance as is A. currasavica.

• They "go away" in the winter, many times leaving gaping holes in the landscape until the following spring when they pop up again.

• Availability in standard nurseries is pretty much nonexistent.

• Mail order of small plants or seeds of native milkweeds is about the only way to acquire natives which definitely precludes them from being an impulse item.

If one has A. currasavica planted in their gardens, be it in the ground or in containers, it would be advisable to trim them way down soon so as not to propagate next season's Oe spores, and will also stimulate adult butterflies to traditionally migrate to their ancestral overwintering sites like God originally intended. I will cut mine back around the beginning of December; that will give any adult Monarch stragglers enough time to pack it up and head to their nearest overwintering grounds.

Let's move on to actually cutting back exotic, perennial milkweeds. The Container Butterfly Garden is home to three nonnative perennial species of milkweed; one from the American tropics, the other two from Africa and Asia. Because of the threat of Oe spore infestation, I will hopefully, over time, replace most of them with native or deciduous milkweed species. I'll keep some Tropical Milkweed (Asclepias curassivica) around to feed any Monarch cats I may put in my cat nursery, as it grows fast and can be kept small in order to place inside the mesh enclosure. Besides the threat of Oe, watering requirements for native plants are reduced vs. thirstier exotics.

Here are some examples on how I cut back my exotics:

 

-Andrew Kliss Photography

Before: Tropical Milkweed, Asclepias curassavica

-Andrew Kliss Photography

After

-Andrew Kliss Photography

  Before: Balloon Plant, Gomphocarpus physocarpus

-Andrew Kliss Photography

After

-Andrew Kliss Photography

 Before: Sodom's Apple, Calotropis procera

-Andrew Kliss Photography

After

All foliage was cut off to eliminate Oe spore infection, and to discourage Monarchs from lingering and not migrating to overwintering sites along the coast as they normally should. Another side benefit to hard pruning is that your plants will come out thicker and bushier the following season!

Two main native milkweed species I'll assess in containers are Showy Milkweed, Asclepias speciosa and Narrowleaf Milkweed, Asclepias fascicularis. I'll be purchasing seed soon and keep you posted on how they fare in containers. In the ground, they grow superbly with reduced water needs. There is one of each growing in the garden at this time; dying back to the ground, having gone dormant. Only springtime will tell if they pop back up to resume growing.

"When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant."

~Author Unknown

Below is a little refresher video on the importance of milkweed in the garden, and a good intro for those new to the blog and butterfly gardening. The hostess is particularly amusing as she expounds on the generous, anthropomorphic male attributes of one particular milkweed plant species, Asclepias physocarpa, wrongly referred to in the video as Asclepias fruticosa, a closely related species:

A. fruticosa vs. A. physocarpa. For all intents and purposes, both are admiral candidates for a butterfly garden.

-Google

 (Also amusingly known as Family Jewels Plant.)

Asclepias physocarpa;   syn = Gomphocarpus physocarpus

-Google

Flowers of A. physocarpa

There is some confusion as to the taxonomy of this particular species, and is at times confused with A. physocarpa. I know it as A.physocarpa rather than A. fruticosa, and believe that the video is using the wrong nomenclature for the illustrated plant.

The Container Butterfly Garden is home to three rather large A.physocarpa that have been excellent host plant additions here. Monarch caterpillars seem to love it. I find this plant to be as popular a host as is A. curassivica. It's easy to grow, produces prodigious amounts of caterpillar food, and the seed pods are curious-looking enough to be a show stopper.

Easy to grow from seed. There are several volunteer seedlings that have popped up in the garden that I will share with anyone if they survive and want to try one. If you wish to try sprouting some seeds of your own, Joyful Butterfly sells packets of seeds for a reasonable cost. As with A. curassivca, A. physocarpa should be pruned way back in the early winter to minimize Oe spores and urge lingering Monarchs to begin their yearly migration.

Here is a graphical illustration of the Monarch annual migration cycle from a onearth.org article entitled: Wind Beneath Their Wings. Graciously brought to my attention by Karen Schwager of Laguna Beach, California.

-onearth.org

The illustration records the adventures of the Midwestern and Eastern race of Monarchs. Our Western race overwinters along the California coast vs. Central Mexico where Midwestern and Eastern Monarchs overwinter.

 On the continuing saga of Tropical Milkweed and Oe spores:

-monarchbutterflygarden.net

Is Tropical Milkweed Killing Monarch Butterflies?

You be the judge. Personally, I see no reason to castigate A. curassavica for its association of harboring Oe spores more so than native species, and may be causing SoCal, south Texas, and southern Florida races of Monarchs to overwinter in their spring and summer stomping grounds without migrating to traditional Monarch overwintering sites, if these faults are mitigated by following the advice of the article above.

Two opposing views on planting Tropical Milkweed. One is by discovermagazine.com, the other by onearth.org:

Gardeners' Good Intentions Are Killing Monarch Butterflies

Don't Stop Planting Milkweed

"On every stem, on every leaf,... and at the root of everything that grew, was a professional specialist in the shape of grub, caterpillar, aphis, or other expert, whose business it was to devour that particular part."

~Oliver Wendell Holmes

Continuing on the subject of Oe spores from the previous post, an article by the Monarch joint Venture, titled Q&A about research related to tropical milkweed and monarch parasites gives us more information on the disease, some of the latest research findings, and some tips on how to mitigate the support and spread of the spores to our local Monarch butterfly populations from our well intentioned gardening actions.

 Photo courtesy of University of Georgia, Athens, Georgia

"Weather means more when you have a garden. There's nothing like listening to a shower and thinking how it is soaking in around your green beans."

-Marcelene Cox

Winter has firmly set in and established itself in the container garden. Jack Frost hasn't left his calling card yet around here, but it's assumed that Jack will show up in the near future, as recent early morning temps have been hovering in the mid thirties. No sightings or evidence of butterfly presence for quite some time now. A few honeybees here and there; that's about it.

The milkweed in the container garden has been pruned back to minimize the spread of Oe spores, ready for next years influx of Monarch butterflies.

 

 

Oe is fairly pervasive now in Monarch populations that have become more localized and non migratory, meaning some individuals and even whole colonies are not migrating as they traditionally do. This shift in behavior is pretty much limited to segments of the west coast race of Monarchs and the Southern Florida strain due to local year round sources of  perennial milkweeds such as Tropical, or also known as, Mexican Milkweed.

Our native perennial milkweeds found growing throughout Monarch butterfly territories die back each winter, unlike tropical milkweeds that grow year round. Oe spores are scattered onto milkweed plants that infected adults visit to feed on nectar or deposit eggs. The eggs hatch, upon which they immediately begin feeding on milkweed leaves and in the process consume Oe spores. These spores germinate and multiply inside of the caterpillar.

If the infection is massive, the cat will die and rupture, releasing thousands and thousands of spores into the environment. If the infection is not so bad as to outright kill the caterpillar, it metamorphoses into a sickened and weak adult that carries the Oe spores on its wings and body, inoculating any plants it contacts, therefor repeating this deadly cycle. The longer the non migrating populations sustain themselves, the greater the chance of contracting and spreading the disease among their brethren.

Oe spores are not a big problem to the heartland races of Monarchs, as the more tender tropical species of milkweeds die back at the first sign of frost and snow. The native perennial species naturally die back to the ground, only to burst back up again in spring, interrupting the Oe life cycle.

Don't be afraid to cut perennial milkweed plants way back. They'll bush out even thicker and fuller next season!

Below are a couple of articles highlighting Monarch butterfly related news that may be of interest:

Monarch Joint Venture partners with National Park Service

MJV Welcomes Green Schools Alliance as New Partner

"I've watched you now a full half-hour;
Self-poised upon that yellow flower
And, little Butterfly!  Indeed
I know not if you sleep or feed.
How motionless! - not frozen seas
More motionless! and then
What joy awaits you, when the breeze
Hath found you out among the trees,
And calls you forth again!"
-William Wordsworth

The time is approaching soon that the Mexican Milkweed, also known as Tropical Milkweed (Asclepias currasavica) in the Container Butterfly Garden will be cut down to mere 4 to 6 inch stubs.

"You're kidding: why?!" you may ask. Not to reinvent the wheel, Is Tropical Milkweed Killing Monarch Butterflies - Grow or No Grow? pretty well covers the topic. The container garden is home to Mexican Milkweed, plus several other California and North American native species. These native species are deciduous, meaning they go dormant during the winter when the plant parts above ground die back, only leaving the roots to regenerate new top growth in the spring. This drastically reduces OE spores that have been wreaking havoc in certain sectors of Monarch Butterfly populations.

OE hotspots are mostly identified with regions of the U.S. where Mexican Milkweed overwinters, meaning, it doesn't die back or go dormant. Hotspots for OE are the west coast strain of Monarchs, and the Florida race that has come into existence due to the large amount of perennial milkweeds now growing there. What is OE? gives a good description of this parasite and why it is so prevalent on the west coast and Florida. Cutting back Asclepias curassavica helps to severely curtail or eliminate OE spores from overwintering on the leaves of Mexican Milkweed.

The best solution to curtailing OE in our gardens is to only plant native species, but that is not as easily done as said:

• Native milkweeds are not very glamorous in appearance as is A. currasavica.

• They "go away" in the winter, many times leaving gaping holes in the landscape until the following spring when they pop up again.

• Availability in standard nurseries is pretty much nonexistent.

• Mail order of small plants or seeds of native milkweeds is about the only way to acquire natives which definitely precludes them from being an impulse item.

If one has A. currasavica planted in their gardens, be it in the ground or in containers, it would be advisable to trim them way down soon so as not to propagate next season's OE spores, and also stimulate adult butterflies to traditionally migrate to their ancestral overwintering sites like God originally intended. I will cut mine back around the beginning of December; that will give any adult Monarch stragglers enough time to pack it up and head to their nearest overwintering grounds.

************************************

   The Gray Hairstreak butterfly can be a common visitor to So Cal gardens when one has Plumbago planted nearby. These diminutive little flyers, if visiting your locale spot Plumbago, they surely will come to linger. For a seemingly monochrome colored butterfly, Gray Hairstreaks are quite handsome.

Found throughout all of continental United States, their home range covers Central America, all the way down into Venezuela. Because of its ubiquitousness, some have suggested that besides the Monarch, the Gray Hairstreak butterfly should be considered the national butterfly.

 

Google

 Gray Hairstreak, Strymon melinus

Larvae feed on an almost endless variety of plants including those in the mallow family, malvas, various legumes and buckwheats. Coloration can vary widely depending what host plant they feed on, many times taking on the coloration of the host's flowers. For host plants in a garden, try Plumbago and Hollyhocks.

 

Google

 Larva

Gray Hairstreak chrysalides look more like fuzzy fly pupae than they do butterfly chrysalides. Thankfully, the adults are cuter and more beautiful than flies... although a choice specimen of a Green or Blue Bottle Fly can be quite handsome within its own right.

Google

Gray Hairstreak Chrysalis

I used to find Gray Hairstreaks at Alta Laguna Park rather frequently flitting about the blue Plumbago flowers in front of the tennis courts, especially in the latter part of July through October before the nights got chilly.