"God made rainy days so gardeners could get the housework done."

~Author Unknown

Good golly Miss Molly: more point/counterpoint on Oe and whether overwintering perennial milkweeds such as Asclepias curassavica encourages Oe spore transmission, yada-yada...

• Point: Loss of migratory behaviour increases infection risk for a butterfly host

• Counterpoint: Tropical Milkweed and the injurious effects of well-meaning people 

What's a conscientious butterfly garden enthusiast to do? Vacillate. The Container Butterfly Garden will still prune back its curassavicas and other perennial milkweeds until an accord is reached. This way, potential of Oe infection is minimized, plus, plants come out bushier and healthier-looking in the process.

Since we've been touching upon winter pruning and cleaning as of late, for those who grow Butterfly Bush (Buddleia davidii), severe pruning (Yikes!) is recommended to encourage abundant blooms and keeping the plant within bounds, especially the standard varieties that can reach 8-12 feet tall if not maintained.

There isn't a consensus as to how drastic one should prune: to each their own. Some leave 3-4 foot stems. Others prune buddleia down to 6-12 inch stubs. I'm in the 6-12 inch camp regarding standard growers.

The Container Butterfly Garden is home to B. davidii 'Nanho Blue', a dwarf that if left to its own resources would reach only about 4-6 feet. It's not cut as drastically as standards are (doesn't need it), as 'Nanho Blue' and other dwarfs grow more compactly. 

Here in SoCal, winter/late winter pruning is recommended, although, they can be pruned back into mid spring without too much negative impact. The earlier buddleias are pruned, the less chance of retarding spring bloom later in the season. Once those leaf buds start to swell and unfurl leaves, it's time to prune, if it hasn't been done already.

The video below demonstrates how to cut standard buddleias almost down to the ground. Chris in the video lives in Michigan and cuts his back in April, most likely due to later spring arrivals his region experiences. Here in SoCal, pruning is recommended at a much earlier date. By April , they are already growing vigorously, getting ready to set blooms in the coming months.

Here's a little diagram detailing how to Prune and Shape Buddleia.

BTW: buddleias are super easy to propagate via softwood and hardwood stem cuttings. If you have a favorite plant you wish to add more of to a garden or give a plant to a friend for the price of a bit of time and a little bit of potting soil in a container, cuttings are a perfect solution. With cuttings, the plants you create are mirrors of the mother stock, whereas germinating seed can produce genetic variability, especially when using seed from hybrids and cultivars:

• This guy is not a sheila. Love that thick, square, iron-jawed stance mate! HOW TO GROW PLANTS FROM CUTTINGS. Everything about this guy is bold, even his YouTube video title.

• How to Propagate a Butterfly Bush details making one's own cutting soil and how to take softwood cuttings. 

• And finally, Propagating a Butterfly Bush (and other Herbaceous Plants).

 

"Gardening requires lots of water — most of it in the form of perspiration."

~Lou Erickson

-Google

Well, we needn't worry about perspiration as of late. The El Niño that climatic prognosticators have been threatening us with has finally arrived it seems. If you've visited the blog recently, you'll notice something new residing up at the top of the pages: tabs. I've been a busy little beaver creating pages populated with pertinent butterfly and butterfly garden information one can glean from. Most, if not all of the info can be found at Attracting Butterflies in So Cal, a web site that has been up for several years now. This was done with the intent of making it easier for one to access basic help with butterfly garden questions without having to leave the blog. Outside links are provided for those requiring greater depth.

As to be expected for this time of year, garden activities have slowed to a crawl, even completely shutting down. Some things to consider are hard pruning your evergreen, exotic milkweeds if you haven't already done so. There may be a bit of accumulated garden schmutz that needs cleaning around the yard. When all is in order, that's a good time to cradle a hot cup of coffee in one's hands, go outside, take a deep, deep, cleansing breath (savor it), and refamiliarize oneself with creation. Yes, there are vestiges of the spirit of Eden still about; we just have to be receptive to them.

After growing for a couple of seasons, the Cassia bicapsularis in the container garden has reached a size where it was time to perform a major lopping. C. bicapsularis can take a hard pruning, even to the ground, and it will pop right back up with the advent of warm weather.

-Andrew Kliss Photography

Monarch Joint Venture: Q&A about research related to tropical milkweed and monarch parasites [A good read. Mea culpa: I want to broach this topic one more time regarding Tropical Milkweed (Asclepias curassivica) and Oe, and how to nip it in the bud. Literally.]

"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.