We have had such strange weather in my area I am having the same experience. I decided to let everything do its thing. To get some blooms later in the season I started direct sowing some annuals seeds. My favorite for that purpose have been Zinnas and cosmos. My plants look weak as it is because of the weird weather I am just not going to stress them any further. We have had so little rain everything is budding early they look weak from all the dry weather. JMO

No- it isn't normal- if you keep them cleaned up & dead-headed they'll bloom until frost no matter when they start. It might help to give a boost of garden fertilizer in July to give them more energy to keep on going. We use 10-20-20 at planting and again in July to spruce them up for shows in August.

According to the Takii PDF file the Canna Cannova Seed strain has taken over 10 years for development to meet the cooler and shorter growing climate of northern Europe. These cannas should fit well within large areas in the United States. Producing F1 hybrids such as this is expensive and time consuming undertakings. They more importantly offer the consumer virus free cultivars that are difficult to find available from most sources. One’s other option would to be purchasing tissue cultured and virus indexed plugs which are also more expensive and definitely not widely available. Therefore, depending on the source, the price may not be out of line for the product in my opinion. Here in the states, I did find a listing for some of the Cannove series available from Ball Seed Co. Given the time of the year and the fact that this is a new product, the availability may be limited or gone. Takii introduced the Tropical Series of canna several years ago and seed became readily available. Kent

If the plants looked like they stretched out, you have to see if they were planted in the shadow and if they were trying to reach out in the direction of the sun. Thats one reason I can think of. Plants that should be planted in the sun, shouldn't be planted in shady areas.