If mine are new bought from a nusery, I spray them down with a 10%bleach solution. I have had bad luck before and gotten melt, and this is where the cats seem fine until they pupate, and then they never shed their skin, they just hang pitifully until the drop. It's awful, and you only need it to happen to one whole batch of cats, before you learn. This year at the beginning of the season, I had a few go that way, because I maynot have rinsed all the plants as well, but now that I am just adding a few at a time, I havent had one melt.(shudder)

Oh, yuck, that sounds awful.

HI Gwynne,

I don't wash but, I rinse. I rinse every single one of the plants I feed to them all-even the Sassafras leaves get rinsed off in cold water. Then I take a paper towel and dry them off a bit before I give them to them. I noticed if I leave a little water on them and then put them in the fridge(I keep them in a sealed bag so if I missed anything its not in my fridge)they stay fresh.
I have not used bleach of anything like that yet, but I have not had to.

Aggie

Oh, I am sorry, I didnt make myself clear. I didnt mean bleach, I mean just rinsing them with water and drying them off. I do that to some degree when I bring them in the house just because little insects often seem to accompany the leaves. Then when I feed the caterpillars, I wash the leaves again. It is time consuming plus I have to buy a lot of paper towels!

With the parsley, I dont wash it because, well, how do you wash a plant like that! Also, it doesnt seem to attract as many pests.

So my question was, how many people wash their milkweed leaves in water prior to feeding their monarch caterpillars.

I rinse but I don't dry them off. I just shake off the excess water. They stay fresh a little longer that way.

After my first batch, out of 8, only 3 pupated successfully. They would either at 5th instar start spewing or puking green stuff and die, or they'd pupate and fall. (More than one falling wasn't a coincidence). I started collecting only eggs and young milkweed plants and started rinsing the leaves under ice cold water (easy to get w/ a well) and rubbed them really well w/ my thumbs. Then I shake them dry, or pat them w/ pp towel. I don't know if it actually helps or not. But I just had my second batch, 13 successfully pupate. There was one death in that batch, a smaller instar showed up in the cage, found him dead, appears that one larger one was munching on the leaf he molted on, he was bit almost in half. So w/ my expirience, YES, I wash the leaves. I don't bleach because to me (not saying it's wrong for those that do) it doesn't seem right. I wouldn't rinse lettuce in a bleach solution to feed my kids, so I won't for the cats either. I do however wash the cages in a bleach solution between cats. (which I'm finding is a real pain w/ this 30gal aquarium!! LOL)

If you have out breaks of OE, or melt, or anything of that sort, you must use bleach, otherwise the next generation is born, and spreads it again. I never knew to use a weak bleach solution until I spoke with Edith about it. She washes absolutely everything with a weak solution. Obviously, for it it is imperative to control disease. I rerinse afterwards with plain water, and I dont have any issues. As for drying the leaves, I don't think you have to worry as much if it is on a bush, because they get rained on. a small catepillar can drown in a droplet of water if you are laying it flat. I find this method frustrating, because they dry out so fast. The picks work well, but my favorite method is to buy the small glad disposable containers, put some water in it, and cover securely with the sticky plastic wrap ( I think its Glad, too), poke a small hole, and stick the plant cutting into it. No drownings, and I can easlily make sure the plant stays hydrated.

Gwynne,
I am with you. If a caterpillar is on a plant outside and eats them as nature gives them to them, then why wash them. I have always thought this funny, especially if the leaves look healthy and clean. If they are really buggy looking, I have always disposed of those leaves anyway as I noticed butterflies wouldn't lay their eggs on them anyway.

me no wash :)

Flutter

I do think that folks further south than we are (in Florida, along the gulf coast through Texas, and in California) wash their milkweed leaves because OE is more prevalent there on tropical milkweed (A. curassavica). It is recommended that they cut their plants in half by mid-summer to allow new, uninfected growth on them as well.

However, that said, I still rinse off my milkweed leaves, and I try to get enough so when I do it, I can refrigerate some of them and they'll stay fresh until the next day's feeding. It's a pain, but I didn't have any OE last year at all. We CAN have it develop on plants, but it is less likely here than in the deep south. That's from everything I have read about it.

If I'm in a big hurry, though, I will just throw some leaves in the containers after cleaning out the dirty paper towels and frass. So far, so good. I did have about 5 that for some reason died as caterpillars or died in the process of forming the chrysalis, or didn't emerge at all (but then, nothing emerged, so it wasn't tachnid flies or anything else). Out of approx. 100 Monarchs, that's not too bad.

I always tried to wash them to get rid of the oleander aphids, too. But, now I hear it is okay for them to consume the aphids, because the aphids are eating milkweed and consuming the cardiac glycosides they are deriving from the plant as well.

So, I may try some without washing this summer, and with aphids, just to see if that works.

A. curassavica is higher in cardiac glycosides than other milkweeds, and I personally believe that is one reason the Monarchs prefer it over the other perennials. Yet, I am also providing perennial milkweeds as well, including cynanchum laeve (milkweed vine), because as a "last gasp" food for the Monarchs, they will eat it for lack of nothing better. It is one of the milkweeds with the lowest concentration of cardiac glycosides.

I have noticed lately that the aphids are fewer and further between, since the relentless rains have moved on from our state, and it is hotter here now, too. Oh, yes, I still have them, but for a while, I thought my milkweeds had been painted, painted orange! LOL!

Susan

I have still been washing the leaves, just to be on the safe side. I guess it cant harm anything. But it sure makes it much more time consuming.

If you're trying to make your milkweed last just as long as possible (because you're running out, or whatever), I read a study that suggests that plunging it in ice water for a couple of minutes when you first cut it and bring it inside will keep it fresh days longer. (The study was about foliage in general, not milkweed specifically.)

I like doing this with my vining milkweed (though I usually just fill up the sink with cool water, not icey). I find I often dislodge a small spider in the process (I also take this time to look leaf by leaf for babes and eggs, starting at one end of the vine and working to the other).

But ... if I am only bringing in a bit of milkweed and I can see it is already free of spiders, I usually don't wash. I've almost never had any of the ooky diseases I've seen others of you talk about (ok, at least not visibly - I understand some viruses like OE can be present even if the caterpillar and butterfly LOOK healthy). When I say almost never - I did have trouble with two dying as they pupated a few summers ago when I was raising dozens at once, and I followed advice here re: bleach for all my enclosures, etc.

Hi Gwynne,

I do not wash or rinse the leaves of plants such as passion vine, pipe vine, fennel, parsley or senna. I just make sure there are no other critters on the leaves. I collect and feed twice a day. I have successfully raised 356 butterflies since March.

I live in Florida where OE (a protozoa) infects Monarchs at probably a 70% rate. I will definitely bleach milkweed when I'm raising Monarchs. It is devastating to see Monarchs infected with OE. Many cannot even break out of the chrysalis, have stunted wings, or wings that never dry correctly. I too, find that Monarchs prefer the tropical milkweed to the native swamp milkweed and butterfly weed. But here the tropical milkweed gets so infested with milkweed bugs and spider mites, it's hard to keep the plants in good condition. Especially now in the 100 degree heat index. I have not seen any actual scientific studies concerning Monarchs in the rest of the state but years ago, I think while they were studying the endangered Miami Blue butterfly, the monarch numbers showed a 70% infection rate for OE in the southern most tip of the state. My anecdotal experience here in the Tampa Bay area says it's just that bad here. So when I raise Monarchs I will not bring in cats, only eggs. I will bleach both the eggs and the leaves.

Anna

Wow, I must say I am surprised this conversation is still going 12 years later!

I live in Northern Ontario, Canada. i’ve been raising monarchs indoors now for 4 years & this is the first year I’ve had a monarch caterpillar die the Black Death basically turning into a black goo due to a virus called NPV. So going foward I am going to bleach all my milkweed leaves with a 5% bleach solution (19 cups water to 1 cup bleach) then rinse really really well, then dry. Even in Northern Ontario, where we have long cold winters, the viruses seem to be surviving, perhaps due to our now milder winters. if you want to see a video on how to do this, check out Mr Lund’s video about NPV & monarchs on You Tube.