Those Canna Leafrollers

Joe Shaw
Fri, 28 Jul 2006 11:26:23 PDT

Hi Gang,

I suppose that familiarity can breed contempt; for a long time I didn't 
bother growing cannas because they were such "ordinary" plants from my 
childhood.  However, I've come to learn they are really nice in certain 
places and used in certain ways.

I've had good luck with the one called 'Praetoria' (or 'Bengal Tiger' and 
maybe some other names) by growing in a large pot (about 16 inches across) 
that is lined with 3 layers of 4 mil insulation plastic.  I filled the pot 
with soil and put the plant in and it thinks it is in a wonderful bog.

But then there are the leafrollers; I know of 2 types, lesser and larger. 
Perhaps there is an in between size too.  After trying Bacillus 
thuringiensis, and encouraging birds to feed on the things, I tried 
imidacloprid.   It works wonders and seems to last for about 3 months. 
Maybe the product would last longer in a climate with less rain or heat.  I 
put about 1 cup (per large clump) of the Bayer Advanced lawn granules on the 
soil around plants in spring, summer, and fall.  There are no more problems.

Do others out there use imidacloprid?  I sometimes hesitate to use anything 
on some plants if I think they will grow out of a problem, or if I don't 
mind the problem.  But, those leafrollers can quickly turn a canna clump 
into a sodden, disgusting mess of rot, worm debris, and (or course) worms.

By the way, I always check any pesticide at EXTOXNET for toxicity profiles, 
including danger to groundwater, etc.  I encourage all to do the same. 
EXTOXNET is a great source of information; after you read up you can make 
informed decisions.

LINK:  Larger Canna Leafroller

LINK:  Lesser Canna Leafroller




Hot today in Conroe, some Amarcrinum still blooming and wonderfully 
fragrant.  I don't know their background; they are unnamed plants I've 
picked up here and there.  I love 'em even though they are not as grand as 

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