Found a caterpillar-like grayish-white worm, about 1" long, tucked in the leaf near the stem - along with lots of little black balls (looked like coffee grinds). Removed the caterpillar, but concerned about the black things - are they eggs? How do I get rid of them? Just recently planted this canna in a pot on my screened lanai, here in FL. Any advice or info you can provide would be appreciated. Thanks!
Canna Lily Pests
Certified GKH Gardening Expert
Without a photo, the caterpillar is hard to identify but there are about five different types of caterpillars found on canna. Based on your description, I think you have the saltmarsh caterpillar - it is hairy and gray when young. For a photo ID click here: https://c2.staticflickr.com/8/7071/7216951916_00905e813c_b.jpg
Regardless of what caterpillar it was, the black balls that look like coffee grinds will be caterpillar excrement and not eggs. I think that so long as you removed the caterpillar you should be fine however I would continue to be vigilant and examine your canna lily for more caterpillars.
You can read more about the insect pests of canna lily here: http://www4.ncsu.edu/~djgofort/insect1.htm