We have three kinds of milkweed, A. tuberosa(butterfly weed), A. incarnata(swamp milkweed) and A. syriaca(common milkweed). They all die back in the fall, and they all have roots that survive the winter and support new plants in the following spring. I think they meet the definition of a perennial plant. Are there varieties of milkweed that die back completely and have to be re-seeded every year?

There are 15 species of milkweed native to Ohio. If any are annuals, it would be news to me but I'm no expert on all 15.

Besides the 3 listed above, we also have:
A. amplexicaulis (clasping milkweed)
A. exaltata (poke milkweed)
A. hirtella (green milkweed)
A. purpurascens (purple milkweed)
A. quadrifolia (4 leaf milkweed)
A. sullivantii (Sullivant's or prairie milkweed)
A. variegata (redwing milkweed)
A. verticillata (whorled milkweed)
A. viridiflora (green comet milkweed)
A. viridis (green antelopehorn)
Ampelamus albidus AKA Cynanchum leave (honeyvine, sandvine)
Matelea obliqua (climbing milkvine)

Linda, as a beginner I would plant one or more of the perennial species that Eric mentions. They are the most common, and in my experience, the easiest to grow. You could also add Tropical milkweed (Asclepias curassavica) which grows as an annual in zones 8 or colder. It is native to the American tropics, but Monarchs love to use it as a host plant. While you're waiting for the perennials to "grow up" (if you plant from seed or a small nursery plant), you can enjoy the faster growing annual.

Of the perennial species that I've grown Swamp milkweed or Asclepias incarnata is the fastest growing. It's a wetland plant, so put it in a moist location.

Linda,
You live south of me and tropical milkweed is a perennial in my neighborhood. If you grow it, cut it to ground around Labor Day since it can mess up the monarch migration. I don't recommend growing it since it can spread and your neighbors may not feel like cutting it to the ground.

I recommend going with swamp milkweed. Monarch caterpillars have the best chance of reaching adulthood on it when compared to common, tropical, and butterfly weed.

KC

KC, the tropical milkweed is perennial for you in zone 6? That's interesting! I thought it was only perennial in zone 9 and above.

I have been planting tropical milkweed here for about 6 years and of all the years I've planted it (I usually plant an average of 6 ot 8 of them) I've only ever had ONE plant ONE year come back - and that was after an extremely (and unusually) mild winter. I would NOT consider that a very good success rate. I don't consider that a perennial, do you? Now - that being said, if I cut mine back around labor day I would lose most of the monarchs, eggs, etc that I raise each year. My tropical milkweed typically thrives well into November, long after many of the species around here have gone dormant due to the summer heat.

~Laura

I would cut it at the time, or even before your native MW dormant period. The Monarchs should be encouraged to migrate, not stick around until it's too late....
Transport your cats to natives and pull the curassavicas.
Plant late nectar to fuel their fall migration.

Ken, would you consider saving me a seed pod from one of your A. curassavica this year? I would love to be able to plant them inground and have them return from their roots. All of my tropical still growing outside die with the first frost. Right now, I overwinter potted A. curassavica in a heated greenhouse, so as to have MW blooming to provide a nectar source during the spring Monarch migration.

My native Milkweeds don't hold up well through the heat and humidity of summer. While they are still growing, only a few leaves are left on each plant and certainly not enough leaves to feed out the little cats that are found on them in the fall. Were it not for the tropical and now, the Asclepias Physocarpus Oscar, there would not be enough food for the little cats to survive if they were to rely on the native Milkweed I grow.

Mary

Mary, try overwintering cuttings in water. It's a lot easier than dealing with seeds and you start with much bigger plants.

I raise a last batch of monarchs (indoors) using tropical milkweed in late August/ early september and released them outdoors on warm, sunny, days. If you're willing to take on a little extra responsibility, tropical milkweed is an excellent garden-friendly plant.

It is also not invasive in northern zones. Sure, a few seedlings come up but they are easy to pull.

If you don't want seedlings, simply cut off the seed pods...problem soved.

I raised and released 53 monarchs in September....probably 2 or 3 would have survived on their own.

If that's the "negative impact" of my tropical milkweed, I'm OK with that, Tony

Well, I grow a few patches of tropical milkweed in the back garden, and this does not seem to affect when the Monarchs stop laying eggs in my garden and start migrating out of this area in the least. They seem to respond to temperature cues, because the nights around here start to cool significantly in late August. In my gardens, egg laying comes to an abrupt halt by end of August, and males no longer patrol the gardens.

Last year I did find a few eggs a little later than usual in the "milkweed field" a mile away in early September . This is a meadow with a nice population of wild A. syriaca where I collect eggs and milkweed leaves, that has significantly greater sun exposure and probably warmer average temps than does my yard.

My last release was around October 2nd.

KC thanks for your input, but I haven't had any problem with the Monarchs staying around too long or anything... just because the tropical milkweed is here until November doesn't mean the Monarchs were. I'm sure we don't get nearly as cold as you do in the winter time so I'm just very surprised you are having such a problem with the tropical. I have not had one seedling ever come up here. Ever.

Sandy - are you here? Do you usually raise late summer Monarchs? Because in the five years I've been doing this, that's the *only time I've had them really lay eggs. The summer before the drought hit, almost every native milkweed I selected for food had cats on them, so I'm pretty sure it's *normal* for the Monarchs to be laying eggs as they travel back south. However, with the severe drought and excessive heat here the last few years, without a doubt the native milkweeds have died off far earlier than they normally would have.

~Laura

I have observed the same in Minnesota. In fact, two years ago they could have easily used our tropical milkweed for WEEKS after I saw the last monarch, but they still moved on.

Since it gets cold faster up here, I do raise the final generation indoors so cool nights don't slow down the metamorphic process.

Tony

Hi Linda;
I am not that far from you in the Dayton area. There are lots of milkweed to choose from. All have different properties. So you are wise in asking questions instead of putting any old thing in and regretting it later. I will give you the info I have on the "big four" that most people grow and we grow up here at the Butterfly house at Cox. I also have grown most of these in my yard.

1) Asclepias curassavica - a.k.a. tropical milkweed, scarlet milkweed, blood flower. For us, we consider it an annual. I have only had it reseed once during a very mild winter. It produces a lot of seeds and can be collected to replant every year. It is loved by monarchs and has a medium high cardiac glycoside (CGs) level (the chemical that makes monarchs distasteful). The levels are important for a variety of reasons. Too high, bad for caterpillars, too low, they are not protected from a variety of things, including parasitic wasps and flies. The only bad things this milkweed is that it is an annual, so you have to replant it. Also in some parts of the country, mainly Florida, it does induce some migrating monarchs to stop migration and start reproducing. Comes in a yellow flower form as well.

2) Asclepias syriaca - A.K.A common or field milkweed. This is the McDonalds of the milkweed world. It has medium levels of CGs. The pros; It has large profuse blooms that attract all kinds of pollinators. The fragrance is unbelievable at times. Monarchs use it fairly well. Comes up pretty reliably year to year. The cons; it is a beast in the home garden, meaning that it can easily take over your yard, your neighbor's yard, etc, through "runners". The sap is profuse if a leaf or stem is broken and some people are very allergic to the sap(as it has tons of latex). Not the best monarch host plant due to the sap (young caterpillars can die from it easily).

3) Asclepias incarnata - a.k.a. swamp milkweed, ice ballet, rose milkweed. Medium to low CGs. Pros: Favorite of monarchs. They will use this one over a lot of the others. Pretty pink blooms. attracts a lot of pollinators. Fairly reliable (some people have trouble getting it to return year to year). Reseeds reliably and does not form "runners". There are not too many seedlings and I can transplant them. Cons; prefers moist soils. If you grow it in full sun, in clay, you need to keep it watered. I have it in high organic soils in partial shade and it does well without me watering it. It can get a little funky as the plant ages. It may truly be a long lived perennial. meaning it really only comes back 2 - 4 years. I am watching that in my garden. Milkweed aphids seem to really like this one.

4) Asclepias tuberosa- A.K.A butterfly weed, shorter milkweed up to 24 inches. Medium CGs Pros; good color, prefers drier sites. great nectar plant. Cons; does not do well in wet soils ( I have lost many to wet winters and springs). Because it is a dry prairie plant, the leaves do not contain as much moisture as other milkweeds. Caterpillars have to consume twice as much leaf material as on other milkweeds to grow the same amount. That is one reason mom will lay her eggs preferentially on other plants.

Some of the others we have used are A. physocarpa (similar properties to A. curassavica), A. verticillata, A. purpurascens, A. viridis. If you have any other questions feel free to ask.

An excellent blog about Ohio milkweed was posted yesterday. It includes only the milkweeds in the genus Asclepias so two of the milkweeds I listed are not in the blog.

Here is a link that might be useful: A Guide to the Milkweeds of Ohio

KC,

Thanks for posting this. Most of the Ohio milkweeds grow here in Oklahoma. And after looking at the pictures, I think Docmom's photo is the Poke Milkweed.

Sandy

KC,
I know you! (chuckle) from Wildlife Gardeners. Fancy meeting you here. LOL
Katie

Having milkweed around late into the year will not encourage Monarchs "to stick around" the same for hummingbird feeders. Both the monarch and hummer use the location of the sun in relation to the horizon to determine when to move north or south. Stragglers will appreciate having something to feed on.

Elisabeth, Thank you for posting all that info about the milkweeds--did not realize that there were different levels of CGs in them.

If a wasp consumes a Monarch caterpillar, can one assume then the plant is a low CG producer.

Also, I was wondering if the wasp then harbors the CG and makes itself unpalatable to larger predators?

bernergrrl, the milkweed with the highest levels of CGs is (Asclepias physocarpa) goose plant, but I think these high levels might kill some of the monarchs too. Every once in a while I will find a small caterpillar dried up on these plants...but not our other milkweed varieties.

Last summer I found 6 instar 4-5 caterpillars on our goose plants. I brought them all in and NONE had been parasitized which was a pleasant surprise.

I am overwintering 3 goose plants....excited to see how they perform as MATURE plants in season two.

Tony

joeinmo,
Because of the introduction of tropical milkweed, there are populations of monarchs that quit migrating to Mexico and now hang out in Texas and South Carolina.

I have personally seen in my own yard monarchs breaking their migration sexual diapause, and using the tropical milkweed in my yard, which meant I had monarchs eclosing in November. The prognosis for their life was dismal because they were heading south so late in the year and monarchs raised on tropical milkweed have less stored fat to survive the Mexican winter.

Once again, my yard was overrun by "annual" tropical milkweed. I don't let it go to seed but it keeps coming back up and it keeps spreading.

Regarding the article I've linked below, you will notice that Tony (coolbutterfly) is everywhere. :D

Here is a link that might be useful: Can Milkweed be Bad for Monarchs

kcclark, thanks for posting the link: "Can Milkweed be Bad for Cats". Great link!

I raised 50 cats indoors taken from outside, starting in November, and all are eclosing heavily infested with OE whether they look beautiful or a mess. Those who release late season monarchs, you aren't testing your monarchs for disease before releasing them. If you did, you'd rip out the tropical and be glad that those eggs were never laid. Every OE butterfly that is released, likely creates 1000's of diseased butterflies.

I was reading how certain birds have learned to test the butterfly for CG content, expertly spitting out the ones with a high CG content.