last year I dug up and threw away several large cannas because the leaf rollers were so bad. Started thinking I don't want to grow cannas again. I have several coming up and I really do love them, just don't know how to deal with the rollers.
Any suggestions?
Chris
leaf rollers?
Chris,
Don't know how you feel about chemicals but sevin dust works for me. I put some in the end of an old t-shirt or sock and then tie it in a knot leaving a pouch at the end. I then gently shake it on my cannas 'til the leaves are almost solid white. I only re-apply if I see new evidence of damage.
thanks, sounds like a good method. I have used sevin long ago.
Hope everything is well with you.
Start with a systemic early on before the bugs take control. Keep to a schedule, and your cannas should look good all season.
~Alice
what systemic do you recommend? I want them to do well this year. My neighbor has lots of yellow ones, I could probably dig a couple of his. He just ignores them. (He is a lot like me, plant it and forget it).
you could use BT. it's natural and the only thing it hurts is caterpillars or any leaf eating worm. when you mix and spray it on, the cat eats it and it goes into his system and kills him. don't use it on plants with any kind of cat you want to keep, ie monarch, swallowtail. i've used this for years on oleander and anything with a cat problem. you can find it in any lawn and garden area under the name of Thuricide. sevin, in my opinion, kills too many other bugs and it's ugly on the plant.
alright now, tell me what BT is!!! I will use it if I know what to look for. I will probably feel stupid, but I just can't think what it would be.
thanks,
Chris
Bacillus thuringiensis or BT is a stomach poison that paralyzes and destroys the stomach cells of the insect that consume it. it is most often sold under the name of Thuracide. it's a liquid that you mix (sparingly) with water and then wet the plant down thoroughly. once they take a bite of a leaf with bt on it, they're done. it doesn't kill instantly, but they can't eat anymore. even though it works like a systemic, it doesn't last a long time in the plant, so you do have to reapply from time to time. the good news is that it is not harmful to anything else.
sounds like a good product, I will try it.
Thanks,
Chris
i have my bottle ready for action! whatever you mix, btw, you have to use, so don't mix ahead of time. wait until you see signs of cats before mixing and applying. good luck! debi
I also got the tip to use the BT on fungus gnats which I had a problem with this winter while rooting my brugs. I didn't know it was good to use ont he cannas. What else will it work on if there a bug problems? Hmmm....I've had a couple of cats eating my brugs. Maybe it would work well for them on the cats. Whatcha think?
there are several different strains of BT. bacillus thuringiensis is the original bt, only for cats and worm type leaf eaters. b. san diego is for certain beetles and b. israelensis is for mosquito, black fly and fungusgnat larvae. i've only used the original bt.
I have mosquitos laying egg larvae in my canna pots. The soil stays moist to promote growth, but I don't want a mosquito farm, either. Will that BT israelentis for mosquitos work on the soil and not hurt my Stuttgart canna bulbs that are just now coming up? The new growth is 4-6" tall, and looks quite hearty.
Also, I discovered this little black caterpiller/worm creature curled up in one of my Cleopatra stalks yesterday evening. It had eaten a series of holes in a completely circular pattern around one of my new babies. Is this animal a candidate for the BT treatment? Cause I'm on it right now if it is!
Please advise soonest.
oh yes, bt will work on him quite nicely. don't forget, this isn't a one time fix all. bt has to be re-applied as needed. it does go into the leaf and i've found that on oleander cats it worked at least a month or so, but everybody and every plant is different. also remember, you may see them, but once they take a bite, they can't eat another leaf. they may live a couple of days, but not doing damage.
as far as the mosquitos go. HD and Wal-Mart both sell Mosquito Dunks. they look like small gray donuts and you can float them in ponds, outdoor fish tanks, pots of water plants, etc. with absolutely no harm even to frogs and tadpoles. i had a large inground goldfish pond in the keys and i would throw a dunk in and they just float around until they disintegrate. one lasts quite a while. you can break them up for smaller areas. i would try it in your canna pots. just crumble a piece up. i used to buy mine from Gardener's Supply, but now, as i said, you can find them pretty readily without paying shipping.
Thanks Track,
What exactly is a "dunk?"
it's solid BT. http://www.pestproducts.com/mosquito_dunks.htm
I highly recommend the bt (I use Thuricide). I keep my canna together just so that it is convenient for spraying. I spray at least once a month. I try to make sure that tehe spray gets down into the new curled up leaves. Also spray the ground well.
if i can ask without sounding weird, why do you spray the ground? just wondering.
Just in case the little suckers or their eggs are on the ground. The ground around my cannas is mulched to hold in moisture and ya never know what is lurking down there.
but they have to actually eat the bt for it to get into their system. getting it on them doesn't do any good. i just don't want you to waste your bt, but maybe i'm wrong?
You are probably right and it is probably overkill. Just a bit paranoid because they are such a problem here.
so far i haven't had even one, but now that it's in print, i'll probably go out and find zillions! LOL i have my bt and my d.earth duster poised and ready.
You can always deal with them the way I do...I squish them in their little sleepin bags!
Im not real fond of most pesticides,but I have used BT on corn borers with success.
I have not had the leaf rollers this year. The cannas look great.
Thanks for all of the good advice.
Chris
Could someone post a pic of the canna with leaf roller damage? I
l'll post a pic of my Canna Cleopatra with those symmetrically punched holes. Amazing, the symmetry!
And now , the edges of the leaves have started turning brown.
here ya go! http://images.google.com/images?q=canna+leaf+roller&hl=en&btnG=Search+Images
purplepetunia, which product did you end up going with?
I use Ortho Bug B Gone, and it seems to work well - it's a clear liquid, so it doesn't cover the plant in white. I sprayed all my plants 4 days ago, and not one of them has a varmint on it right now.
Ortho's website says that Leaf Rollers is one of the pests that Bug B Gone will kill, and they were right.
I wish that I started with something systemic - didn't know I was going to have them, didn't have them last year.
From now on I'll know.
Steve
Okay. I've read all this. Now, please tell me: My cannas are 3' tall, and the leaves are rolled up tight as a leaf roller... Anyway, should I break the infected leaves (with the leaf rollers inside) off, put them in a plastic bag, and THEN put the BT on the plants?
The leaves look all dried up and awful... thanks for your advice.
Here's a pic with leaf roller damage.
if i were you i wouldn't "break" the leaves. i think that once your damage is really bad, cut them back to the ground, then as they start to grow again (and they will), spray bt every other week until it's time to cut them down for the winter. this is just a suggestion and what i would do. others may do it differently.
Thanks, trackinsand. I will do this very thing. I have not been able to have cannas for several years because I haven't "tried" to rid myself of the leaf-rollers.
i'm not familiar with the life cycle of the roller, maybe ceejaytown could help on that, but i suspect that it will take maybe a couple of seasons to see big improvement as far as the amount of leaf rollers you have. if the eggs overwinter in the ground then i'm thinking about a lengthy time span. all i really know is that bt does work, on any caterpillar and is the least harmful to the environment when done properly and by that i mean not harming the good caterpillars. i normally don't spray until i see a problem because bt doesn't stay in the plant that long, but in your case i suggested every other week as a precaution. good luck and let us know how it works out for you.
I really appreciate your help. I'll let you know!