Hi, Most of the milkweed varieties need cold stratification, but the one called Tropical Milkweed or Asclepias curassavica doesn't need cold start--you can plant it directly although it may be towards the end of the season when you will get blooms and enough plant for the caterpillars.

You can do the cold strat in your fridge and then take out your flat and put it out--keep moist and then plant out the seedlings, which will give you a head-start on next year. It does take a year or two to become a substantial plant.

What zone are you in?

2 years ago, I traded for some Tropical milkweed seeds from 2 different people, so I sowed both of them around mid-April or so? Well it turned out that one of the batches of seeds was Asclepias tuberosa (butterfly weed) and it sprouted great without any cold stratification (and now I've got some 2 year old plants). Not sure if other species would sprout, as I've always sowed them with cold strat.

I sowed my A. curassavica about 10 days ago and it hasn't sprouted yet, so I don't think it's too late to sow this one, especially if you've got hot and sunny spots for them, they will catch up. And if you have plenty of seeds, it doesn't hurt to experiment and try others!

Another note, it's not necessary to start them indoors either, I've got mine in cups outside along the foundation on the south side the house.

I live in zone 7 guys, thanks for the info but if i stratify swamp milkweed for 30 or so days and plant the seeds in mid june indoors is that too late. I understand that i can probably plant seeds that do not require stratification.

I'm in Dallas and have some A. asperula, "antelope horns" (native to southern plains and southwest). Is it one that doesn't need cold strat?

~ freshair

If you want to try the swamp milkweed now, I'd say go for it! The first year from seed it is mostly going to establish a root system so this will give you a leg up on strong plants for next spring. The wonderful thing about perennial plants is once planted, they will come back stronger and grow larger with each new season.

Tropical Milkweed or Asclepias curassavica seeds will grow slowly for a bit, then take off so go ahead and plant some of those for this season. The Monarch mama's will nectar off of other plants but she NEEDS the milkweed leaves to lay her eggs on so if you don't get blooms off of these late starters, it's not so important this season. She will use the tender new leaves of even tiny little plants. In your current situation, the only problem I see is a lack of MW leaves to feed the little cats once they hatch. They eat A LOT! Next year, you can start the plants earlier in the year, which will allow enough growing time for you to get blooms and seed pods from them, if desired.

I start many new plants by pinching out the tops of the Tropical Milkweed - or Asclepias curassavica. They root very easily and quickly when stuck into a moist potting mix and kept in the shade. This is another way to expand your plant numbers once you have some up and growing.

What I can't understand is why local nurseries haven't picked up on the growing interest in these types of plants. Maybe in time they will become more available.

Bless your heart for wanting to plant for the butterflies. It is a very rewarding experience and one I'm sure you will enjoy.

Mary

Thank you! So im gonna cold stratify the swamp milkweeds and plant them in mid june. Should i plant them or will they be too weak for the winter. Could i keep on raising them through the winter or would that disrupt their "growing cycle" because i would plant them in the spring

I did some late seedings a couple of years ago, and the plants came up, but they were thirsty and easily hit by July heat. They can make it, but you'll have to tend to them carefully.

Another option would be to throw your seeds out in September-October, right when the plants would be shedding their seeds on the ground. Then they can cold-stratify to their heart's content all winter and give you little seedlings in the spring. My swamp milkweed bed went from thirteen plants to over a hundred this year, just from re-seeding, so the seeds are fairly hardy.

Jeff

if i were to fall sow could i do it in containers like those jiffy tray flats

That's an interesting question. My intuitive response is that they would dry out too easily.

I would probably just scratch the ground with a rake, throw the seed out there, and cover it up.

I sow all of my seeds with the winter sowing method and it works really well. I take an empty gallon milk jug (the clear kind) and punch drainage holes in the bottom. Then cut it in half around the middle, leaving the handle intact; it will act as the hinge. Put in at least 3 inches of potting soil and then using the sprayer on your sink (I found that works nicely) make the potting soil wet until it's running out of the bottom. Let it drain in your sink for awhile. Then sow your seeds and cover them with some potting soil. Tape the jug shut with duct tape and the seeds will be protected all through the winter. Sit them outside where they can get moisture. It could snow 10 feet and it won't hurt them one bit. The milk jug acts as a little greenhouse over the winter and protects the seeds from being eaten by any critter, and the seeds won't get washed away by any heavy rains. Oh, and leave the cap OFF of the jug. There has to be ventilation.

I wish you'd have been here a couple months ago when I was giving away swamp milkweed plants for the postage. I had about 100 big plants in my milkweed patch and I wanted to try something different this year. I was glad that people could use them. I don't know if any small plants are coming up or not from last year. If there are, I could send you a few, but they'd only be little (like a couple inches) plants. I had deadheaded most of the plants so I wouldn't have a lot coming up this year since I want to convert it into another kind of milkweed patch, probably tropical milkweed. A few plants might have missed the sprayer. I have so many weeds coming up in there that I just went through with the sprayer on Saturday. I don't usually like to spray, but it's a real mess in there and something had to be done before it gets tilled.

If you'd like to take a look at it, I'll include a link to the website where I learned about winter sowing.

Here is a link that might be useful: Winter Sowing

Thanks. I learned something!

Jeff

Mary in Little Rock ~

When you "pinch off the tops" of your Tropical Milkweed to start more plants, what are your steps? I've started rooted cuttings before, but only on shrubs and trees.

~ freshair

~freshair,

I just cut a top shoot from a growing plant, about 5-6 inches long, pinch out the growing tip, then remove the leaves on the last one or two leaf nodes nearest the bottom of the cutting. I dip the end going into the potting mix in rooting powder or clonex so that it covers a leaf node going into the potting mix (I'm not certain this is really necessary on this particular plant but couldn't hurt), then stick the cutting into a light dampened mix of Promix (brand name) potting mix and perlite, about 50-50. I've also just stuck the shoots into a small pot of dampened Promix (or any good quality, light potting mix). If there are large leaves on the shoot, either cut the leaves in half or pinch off some of them so the cutting doesn't lose a lot of moisture via the leaf surface.

Now set a top half of a 2 liter plastic cola bottle (minus the cap) down over the pot and put them in the shade. Don't let the cuttings dry out. In a week or so you will notice new growth at the exposed leaf node. It is rare for me to have a cutting fail so I figure they are super easy. I mist the cuttings when I think about it but keeping them in the shade until they begin to put out new leaves is very important.

Before I had a big butterfly enclosure to raise the little cats in, I'd take shoots from a growing MW, stick them into a block of moistened florist foam and use the MW that way to feed the little cats. They would eat those MW shoots right down to a stalk, even eating part of the stalk. If there were at least two leaf nodes left, I'd stick the lowest leaf node down into potting mix and almost everytime, it would root and grow new leaves from the exposed top leaf node. I've got some pots on my deck right now that have five or six little MW plants in each pot that were started this way. This variety of MW must have some good, strong genes!

Give it a try and I think you'll find it very easy to multiply your tropical MW this way. I feel it is probably quicker than starting from seed. I have some tropical MW seed I planted a month ago and there are only two sets of true leaves on these little plants right now.

Mary

thanks, mary - that's more or less the process i've used with shrub/tree cuttings (with logical variations) - so i'm off to the patio to start my milkweed cuttings :-)

~ freshair

What happens to the original milkweed? Does it flower? Die?