Hello! My cannas here in Oregon City do not require mulch...I suspect yours won't either. In any case, my cannas got tall enough, BUt didn't start blooming until way way late. I think it was lack of hot weather this summer. Did you try adding some nitrogen to the area in question?

Hi, lalameija, We couldn't by without mulch up here when it often drops down to the 20s. We've had frost every night the past week and expect more this week, so I need to get the beds prepared. No,I have never added nitrogen to the area. I've been using Shake 'n Feed fertilizer.

I was disappointed with my cannas this summer?? too. They were half the size of usual and never did look lush. I put it down to the lack of a summer in 2007. I wonder too about the mulch -- if it remains in place in the springtime it takes too long for the ground to warm up.

My cannas were like lalmeija's. Grew a little less in height and flowered way late. Gresham OR
Duane

Mine were awful here in WA as were my families down in Portland area (Stafford). They didn't even bloom.
My sister-in-law's are in direct sun all day too. They didn't bloom either. Hers are usually stunning.

Cannas love hot, sunny weather and I suspect the poor performance was due to the cold, wet weather most of us experienced. Did anyone have beautiful cannas this past summer in the PNW?

Depending on specific variety, cannas are hardy to 0-10F, so should be OK in winter in most areas of the PNW. Failure to overwinter is usually more related to not good enough drainage rather than to cold. And I agree with Madrone that canna performance is directly tied to our summers (or lack thereof!). Soils here are very slow to warm up in spring and our cool summers just don't encourage enough growth to produce the taller, quick to bloom specimens you see in other, hot summer areas. One way to get around that is to grow your cannas in containers - container soils heat up much faster than existing planting beds and you can stage your containers to obtain the maximum reflected heat to encourage growth and flowering. Easy to overwinter in containers and you don't have to worry about excessively wet winter soils, either. However, if you are dealing with 100's of tubers, that may be a bit of a major chore :-))

I'd be cautious about adding too much nitrogen - nitrogen promotes leafy growth, often at the expense of flowering. Using a good all-purpose and fairly balanced fertilizer should be sufficient......or, mulching with compost will supply all the nutrients these plants need, unless you are growing them in containers.

Mine are in big pots, I divided them, added new soil and fertilized them with several different fertilizers and I had the most growth and blooms ever. They just took off but I admit I had not dumped them out and divided before. Some were several years old.

Thank you for all the informative responses. In this case, misery does not love company: I wish all of us had enjoyed tall, healthy, huge-blooming cannas this year. At least I feel somewhat better knowing my neglect was not the total reason for their poor performance. I'll try to salvage some, plant them in containers and bring babies into the garage.
I appreciate the great advice I receive on this site!!!