Growing and planting Red Canna King Humbert
I bought about 20 Red King Humbert canna bulbs. I planted them in April 2014. This is the first time I bought these bulbs because I love to see them in gardens around New Jersey. Now the problem is that some of the bulbs die out and I only have about 8 that sprouted out and growing. Why did some die? Thank you.
First, there's a good probability that some of the rhizomes you planted were not viable. You might try discussing this with the store from which you bought them, possibly they will refund or give you some more plants.
However, even if they don't, you can go on from where you are. First make sure you have the best culture for them. https://www.gardeningknowhow.com/ornamental/bulbs/canna/canna-lily-care.htm
Then take up the rhizomes and store them over the winter, and plant again next year. here are some tips for over-wintering: https://www.gardeningknowhow.com/ornamental/bulbs/canna/storing-canna-bulbs.htm