It has been such a busy week! We had a blizzard here on Sunday, 19" and one more inch tonight. I am a little stir crazy, all I can do is keep looking at butterfly gardening stuff online to keep me sane. Only 44 days until the first day of spring!
One of my favorite parts of winter is my greenhouse at work. My 20 flats of trop mw popped last Friday and should be a good size just in time for the Earth Day event. We give away about 200 plants and 300+ seed bombs of common mw. So we will be making seed bombs in the coming months.
Today in the gh, I prepared seeds for cold stratification. Specifically, three spp of mw. The first thing I did was to get some clean play sand, don't just pick up sand from the beach. There are microorganisms in there. Make sure the sand is damp. Next, get your seeds together, This year I am cold stratifying common, swamp and tuberosa. The topical does not need cold strat. I simply put a few handfuls of seed and a few handfuls of sand in each 1 gallon freezer bags. Mixed them together. I labeled the bags and dated them. They will stay in the fridge for 6 weeks. Before I store them, I place each bag in another 1 gallon bag. This keeps the bags from loosing too much moisture over the 6 weeks in the fridge
There are many varieties of milkweed for the Chicagoland area. These are my experiences with growing them. I would love to learn about your experiences in the comments section.
The 5 that I grow, are
common mw Asclepias syriaca- a native to the Midwest, in suburban areas it will grow in vacant lots and disturbed areas. It is very adaptable, being able to be grown in a garden, it is not picky about its soil. In my garden, it tends to move from place to place from year to year. I think it is nitrogen hungry and when nutrients are depleted then the roots move on. I have no scientific data for this, but it is a plausible reason for why the plant moves around the garden. I initially planted 2 little plugs on the east side of my house many years ago. I thought it would be a good spot, out of the way, not in my formal landscaping.. yada yada. The mw had different ideas, felt it would be better on the west side of my neighbor's house. So it spread under the lawn in between and it became a great place for finding eggs. My neighbor was a very sweet kindergarden teacher who occasionally caterpillar-sat for me. When the next neighbor moved in, she destroyed it. Even after I explained to her what I was trying to do. Who knew a florist could be so hostile? However, the first time she cut it down it sprouted right back and she actually did me a favor. I collected a lot of eggs before she officially killed it. Her property, I know.
Then the common popped up in the front landscaping. Oh boy. my nice landscaping. Well butterflies are more important. Especially since I have changed my philosophy from just gardening for the flowers to gardening for the insects! For the past 4 summers I have had 50+ stems of common growing. Weirdly, I did not have that many seed pods last year. Even with all the spring rain. Weird.
swamp mw Asclepias incarnata- in nature, this plant thrives in marshes and places where the land is flooded periodically during the year. It can tolerate a fair amount of drought too. The adapability always amazes me. It will grow almost anywhere you plant it. I had just a few of these plants in years past and it grew to almost 28 plants before I had to take some out. It is not a plant to put in the front of the border, which is where it needs to be to be accessible for the egg hunting. Then there are the aphids (I will get to that later) . My biggest problem with the swamp mw is the way the leaves turn purple in the middle of summer. I cannot figure it out. is it a nutrient deficiency? Virus? In any case, the monarch mommas do not like laying eggs on it.
The butterflies like the flowers a lot.
butterfly weed Asclepias tuberosa the orange mw. This is a mw that usually has few eggs an cats on it. The whole point of monarchs laying eggs on mw is the chemicals in the sap that is stored in the cats.' body and the butterflies exoskeleton. This chemical makes the monarch poisonous to birds. Since the A.tuberosa does not contain very much of the poison monarch don't lay eggs on it very often but I do find them occasionally. I see bees and butterflies on this plant a lot. My experience in growing it has been varied success. The first few times I tried to grow it, I didn't know how sensitive is was to wet cay soil. It died spectacularly. This is a plant that resents wet feet. Especially over the winter. So plant it in well drained soil and plant lots of it! If most of your garden is clay soil, then amend a large hole for this plant. I recently planted a bed with only A.tuberosa and Liatris I cannot wait to see it bloom!
prairie mw Asclepias sullivantii- or Sullivant's milkweed. This is a new species to me. I needed a milkweed for work that is not too tall and doesn't run around the garden like the common. This plant is only 4' tall. So more on this plant after this coming season.
tropical mw (annual) Asclepias curassavica I had a hard time finding any cats. or eggs in my garden until I started growing this mw. Then I started planting it all by itself in pots that I can pick up easily. Last season, it was 2g pots and 1 qt pots. It is a great plant in a pot, water deeply and the plants grow really big and seed well. This is the only mw that I fertilize. Last season I was running out of trop mw to feed my cats. So I got a hold of some seedlings of trop. Once I planted these up and got them out of the transplant shock, I started finding eggs. It took just a couple of days for them to perk up and as soon as they were, the monarchs were all over it.
One of the challenges of growing all mw but especially trop. mw is the aphids. I struggle every year with this. They are oleander or orange aphids. Last season was particularly bad, they even attacked the common and swamp pretty bad. To control I will not uses chemicals. I spray them off and squish them. If you squish make sure you rinse the plant off at the end. With the trop in the pots, I would pick them up and check for eggs then squish then rinse. I started noticing in August that there were quite a few predatory wasps attacking the aphids. These wasps are very tiny, normally you never see them. There were so many last year, I observed them actually laying their eggs in the aphids. You know that they are there because the aphids turn brown as the wasp goes through their life span. The wasps last year were prolific, between them and the cleaning did, the trop mw was clean by third week of August. So nice to see natural predators really working.
I hope this season the wasps return in such huge numbers!