Anyone hungry? Asclepias syriaca

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    I would LOVE to get this plant growing with its HUGE leaves… Common milkweed. And, what’s more, you can eat it too:

    PS If anyone has a Juneberry bush, please send me some. :)

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    I think the wasps help the Giant Swan Plant get pollenated more then Moths & Butterflies. I had flowers visted & trod all over by Butterflies & no seed pod even started to develope. But there was seed pods on the ones Paper Wasps visted. (Later eaten by caterpillars).

    Also, bear in mind N. America has native Paper Wasps. So they don’t cause the same problems as here in NZ.




    in some areas it may be necessary to encourage nesting by paper wasps.

    Somehow I just can’t imagine myself building little houses to encourage paper wasps! ROFL



    Me again, Milkweed – this may be helpful – I posted a query on the dplex list and these are the responses. Interesting that we don’t get these sorts of issues with the African speices, i.e. “swan plant”:


    …they need cross pollination that is why insects feeding on
    Asclepias get their feet caught in the “pollinia” and then the insect carries it to another plant. They also need diversity–especially the Purple milkweed.

    This website has a good picture of the process

    Asclepias purpurascens:
    Third paragraph, in the Summary
    “Fruit production in this plant tends to be very low, and may be limited by inefficient pollination, selfincompatibility,
    interspecific pollen, isolation, selective abortion, parasitic fungi, and inbreeding depression. Other factors controlling fitness and survivorship need to be investigated”.
    “We used to be under the happy misimpression that asclepias might self-sow to excess. We’ve since learned that, like orchids, asclepias depend on specific pollinators, and are quite unlikely to set seed unassisted outside their natural ranges…”


    Most of the milkweeds appear to be self incompatible – meaning they have to receive pollinia from unrelated individuals… In the case of A. syriaca, this means from individuals from other clones. The only species I know of with high self compatibility is A. incarnata – an adaptation that may be related to the manner of dispersal of seeds (probably on the feet of birds) followed by colonization of relatively impermanent habitats (wetlands) and often widely separated habitats (before man).


    In central Maryland, purple milkweed is the earliest milkweed to bloom (about a week or so before the A. tuberosa). I have plants in my butterfly meadow that were grown from wild-collected seeds of different genotypes, and every year they bloomed beautifully, but had only set seed once in 20 years. Then in the last 5 years, I started cutting them back before flower buds formed, causing them to bloom later. Since then they have set seed every year. It could be that the early bloom doesn’t always coincide with the emergence of their common pollinators. But when they bloom later, the pollinators are plentiful.


    Studies have shown that the most effective pollinators of many milkweeds are large to medium sized wasps. Paper wasps (Polistes) are among this group of effective pollinators – and following bad winters these wasps can be scarce for milkweeds blooming early in the season.

    For large scale milkweed seed production – in some areas it may be necessary to encourage nesting by paper wasps. This can be done quite easily by creating wasp domiciles – two pcs of wood about 4×4 inches nailed together at a right angle with a similar or slightly larger pc used as a roof. The open side of the nest structure should face east of southeast. These structures are placed atop metal fence posts at a distance from the garden so the garden activities will not disturb the wasps. Good for controlling lots of unwanted leps in gardens but not advisable if you are rearing monarchs or other butterflies in your garden.

    (I’m thinking that the “east of southeast” should be changed to “east of northeast” for the southern hemisphere, but have written to Chip asking for clarification on that point.)



    Fantastic, Milkweed. That would be wonderful. Where are you – and what are the butterflies like where you are?




    Jacqui, i have A.syriaca growing in pots and it has flowered several times but no seeds so far. Ditto my A.purpurascens (purple milkweed). I think they need cross pollination from another plant of the same species for seed to occur. Eventually it’ll happen cos new and more stems rise each summer.
    On a happier note, i got several seed pods off A. Incarnata (white flowered variety called Ice Ballet)this year and will send these on to you to sell through the club when i get back to NZ in July.

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