Help with tropical milkweed
Hello! Two years ago, a GWer was kind enough to send me a generous supply of tropical milkweed seeds from his yard. A few plants sprouted in the springtime (SW facing bed that receives strong sun from morning til late afternoon). By the time they reached 5-7" tall, they were covered with aphids. I blasted with the garden hose several times for a couple of weeks, but the aphids returned. I left them alone, and the young milkweed plants all eventually died.
This past spring, I was happily surprised to see TWs sprouting yet again! A few of them reached ~ 18" tall, then the decline started. They lose most of their bottom leaves, and the tops slowly die.
Here's a morning shot of one of the older shoots:
Here's an afternoon shot:
Here are some of the younger plants. They start off looking green and healthy, but don't say that way long. (You can also see the bare bottoms of two older shoots, leaned over from being top-heavy, apparently.)
Any advice would be appreciated, as I'm really trying to get back into butterfly/monarch gardening . (And, yes, I do realize the TWs need to be cut back every winter -- and plan on diligently doing so if I could ever get them to grow and bloom!)
Comments (11)
javiwa
6 years agolast modified: 6 years agoRelated Discussions
tropical milkweed problems
Comments (1)Michelle, I grow them every year and all I can tell you, is that I let them dry out before I water them, they get lots of light, a lean soil, and I don't feed them. Do you have air circulation? I have a ceiling fan that I turn on if it gets too warm and humid in the room. Mine drop their lower leaves as they grow and sometimes if I don't get them watered soon enough, the bottom leaves will yellow and fall off, but after they get watered they revive. I am growing mine in a south window with lots of light. I have over 200 plants, and haven't lost any of them. They are currently between 4 and 6 inches tall. The farmer's markets begin in two weeks, so they have to be ready to sell. It's not too late to start some more plants as they germinate and grow quickly. If you don't have any more seeds, I have some that I can send you....See MoreSwamp and tropical milkweed
Comments (9)I fertilize my tropical milkweed a little, so it gets to be about 5' - 6' tall. Once it gets over about 4 1/2' or 5' tall, I quit fertilizing it, because if it gets much taller than that, it'll bend over to the ground after a rain and need to be staked. It gets about 4' wide for me. You don't have to prune the plants after the cats eat the leaves - and they'll eat ALL of them! - because Asclepias curassavica/tropical milkweed resprouts on its own. I usually do cut it back to about 4' tall, however, and fertilize it a little again to help get it going again quickly for more cats. Tropical milkweed likes a lot of sun, but mine doesn't get a whole day's worth, because there are woods on one side of my garden. I'd say it gets about 3/4 of a day's sun. If you're in Seattle, where I assume it's much cooler than here in summer, I'd imagine yours would need as much sun as possible. You can raise tropical milkweed in pots and bring those pots in during the winter, but I did that with several plants this past winter (4 or 5 plants) and only two survived. I don't know if the roots stayed too wet, or they need more heat than they got. I don't have a (heated) greenhouse. Tropical milkweed works great for me, makes copious amounts of seeds, I even find volunteer seedlings on the ground near the plants. Most of us on the Butterfly Forum are in the hot/humid Southeast or very hot Texas, so I'd be interested to know how yours does in Seattle. Keep us posted! Sherry...See MoreCutback Milkweed?
Comments (8)Asclepias curassaica is native to Mexico. It is not native to the United States and Canada. Asclepias curassavica (tropical milkweed) is considered naturalized in the United States and Canada. Tropical milkweed was first noted as being in Florida back in 1942. Dr. Urquhart noted in his book that it was being used by Monarchs in the Caribbean in the 1860s. With regard to breeding activity in the United States during the winter, Richard Funk back in 1968 wrote about finding Monarch larvae in Yuma, AZ on December 26, 1965 on Asclepias tuberosa, butterfly weed, which is a native species of milkweed, but not native to the Yuma area. It was growing in someone's garden. There are other native milkweeds that are natives and that grow year round in areas where it does not go below freezing. Many coastal states are just the right temperature for plants to survive and for Monarchs to survive and for some to breed on native milkweeds in the United States. I agree that tropicals should be cut back in the winter, but I do not agree that they should not be planted. Tropical milkweeds do not stop the migration and do not harbor disease if cut back in the winter. Monarchs would not migrate from Mexico where tropical milkweed is a native in many Mexican states and grows and flowers year round, if that was the case. My advice to people is plant as much tropical and native species of milkweed as you can. Natives often take 2-3 years to become established. I also grow Asclepias physocarpa. This summer I found that some caterpillars that were eating common milkweed and looking sickly when put on A. physocarpa livened up and doubled their weight within days of being introduced to it. A. curassavica and A. physocarpa are more toxic than many of our native milkweeds and therefore provide more protection for Monarch butterflies. I took a picture of one of the Monarch caterpillars on A. physocarpa to document how healthy it looked; unfortunately, I didn't have the foresight to take a picture of it before I changed milkweeds. Here is a link that might be useful: OVERWINTERING OF MONARCH BUTTERFLIES AS A BREEDING COLONY IN SOUTHWESTERN ARIZONA...See MoreLos Angeles County milkweed and tropical MW info
Comments (6)Thanks so much for this information, needtoseegreen. "The three species you mentioned", is that the newsletter you're quoting? I have been concerned about planting non native milkweed so I'm very glad for this post. I grow the milkweed that is native to where I live in So. Cal., if was growing in the yard for decades and I didn't know what it was until 2 years ago. Luckily the roots survived my weedings. It makes sense not to fool around with mother nature and grow non native milkweed. I'm not surprised with the findings you listed from the newsletter. I have read about the toxicity of the "milk" varying and that So. Cal Monarchs aren't used to the toxicity level of tropical or other non native MW's, but I have no opinion because I don't know for sure. I would trust what Monarch Watch says on it. The Monarchs that visited my yard last year when I tried a small plant of tropical in addition to the native (A. fascicularis) didn't lay eggs on the tropical. The tropical didn't do well in my heavy clay soil either. Could you please forward the newsletter to me? I'd be very interested. Do you think they would mind if you mentioned them here? I don't recommend using anything but water on the milkweed, because even a tiny amount of bleach in water will kill the caterpillars on contact. I found this out in my cat raising indoors for the first time starting a few weeks ago. The newly hatched Monarch cats are way too small for anyone to notice, they are extremely small and are hidden under leaves, or can be embedded in the tender growth at the top of the stem. Insecticidal soap would kill them and leave a toxic residue (to them). I recommend crushing the aphids, and wearing latex gloves, they stain the skin. Hosing them off would be hard on the new cats and would likely wash them off too. May I ask what MW species you grow? since you're in the same growing zone and area as myself. Any way to find out if the other species you listed (other than A. fascicularis) are native to the L.A. area? Any So. Calif. milkweed and Monarch breeders who read this, could you share what species of native MW you grow? I am battling black mildew on my A. fascicularis leaves, and pulling off the affected leaves daily. It's a huge task. I need to keep a clean food supply for all the tiny cats I have brought in. Today I picked about 5 stem tops and found 4 more tiny cats, and the nights are getting too cold for them. Just the problem that the newsletter addressed; tiny cats hatching in weather that is too cold due to abnormal breeding spans encouraged by the non native MW species. (I get the impression that tropical MW to a Monarch is like catnip to a cat) Sadly all the nurseries, even Home Depot carry these non-native MW's, and I think they have helped create the OE problem. The cats I raised last December-January all emerged as OE infected butterflies. The reason for this (according to what I've read) is because since the plants have been visited all season by butterflies, all that "foot traffic" has raised the probability of contamination of the plants and egg by the microscopic OE spores. The unnaturally long breeding season puts Monarchs in a perilous position not just weather wise, but disease wise. Sorry this got too lengthy. This fall I'm dipping the milkweed used for feeding (clear of eggs or tiny cats), in water with a few drops of bleach for 10 seconds, and rinse it well. The 2 Monarchs I released today had questionable looking thoraxes (possibly OE infected), I was torn about releasing them. They were not raised entirely indoors. I need to get an inexpensive lighted microscope to check for OE, any suggestions where to get one, anyone? Thanks. It didn't work for me to raise the eggs on the narrow leaves, the larvae all got black death or NPV (or?) at various stages. Now it's the cut MW in water, tons of work and I can't disinfect the MW that have eggs on them. I'm worn out! It's a full time job. Feels like changing baby's diapers all day long. :)...See More
Jeannies_Garden (Tx 9a)
6 years agoHi Javiwa,
I live a little southeast of Houston and I can't keep enough milkweed to feed all the monarch cats I have. I also grow the tropical milkweed from seeds in the spring and take cuttings all year (in the greenhouse) if possible. I'm having trouble with die-back and having to cut back stems which could of grown a lot more leaves that are much needed this time of year.
Just took this picture...
I will most times let nature take care of the aphids, but when I do see them show up in large clusters, I use my fingers to smash them or spray the plant down with soapy water in a spray bottle. Soak down both sides of the leaves, the stems, the soil around the plant and after about an hour, I hose the plant off and no more aphids.
Happy Gardening, Jeannie :)
javiwa thanked Jeannies_Garden (Tx 9a)javiwa
6 years agojaviwa
6 years agojaviwa
6 years agolast modified: 6 years ago(Ooops...sorry: this pic goes down below, but I can't figure out how to move it!)
NEW POST STARTS HERE: :)
Gosh, I'm having such a difficult time of this -- is there such a thing as an infected bed?
Last weekend, I planted a 3-gallon asclepias tuberosa. The weather has finally cooled down into the 70s-80 high, nights 50s. It was doing great until just this morning: I noticed yellowed leaves with spots on them:
These spots look similar the ones on my Esperanza which is planted ~ 20' to the right. While my Esperanza is somewhat shaded by the neighbor's oak, the milkweed gets full sun from morning til 4 p.m. (this time of year). My first thought was: too much water? I poked my finger into the dirt: cool to the touch and slightly damp, but not soaked.
I also noticed that the milkweed leaves were all droopy:
We were away yesterday, so skipped watering. I gave it a good dousing today, and the leaves immediately perked up. So, now I'm confused about what's causing the spots, as the plant doesn't appear overwatered (based on today's drooping).
Many of the leaves have halo-looking lesions/spots on the top only, with no discernible issues on the underside:
...while other leaves are damaged on both upper and lower surfaces:
BTW, the red pentas are flowering, and most of the leaves look okay; but over the summer, it's apparent (by the leaves) that something hit them, too:
For reference, a look at the bed (area shown is ~ 32' l-r):
I think that plant to the left is an angelonia -- purchased ~ 5 years ago, so I can't remember...small purple blossoms (see pic at beginning of post). It's carefree and doing fine -- it anything, is suffers from too little water.
We planted the gardenia ~ 20 years ago -- I do nothing to it, and it's perfectly fine (though the two right branches seem to be protesting a bit lately...starting to green up again).
Any help would be greatly appreciated. As the Monarchs are starting to lay eggs on the milkweed (yay!), I don't want to start spraying with fungicides or chemicals. Thanks, all.
javiwa
6 years agoThanks again, Crunch. I've just emailed the county extension, along with photo attachments. If need be, I'll make the drive down and bring them the leaves. As of this morning, more yellow leaves at the bottom of the plant -- very disheartening:
And with the chilly weather coming today, I don't think this little guy will be a very happy camper.
javiwa
6 years ago
jurasico