Since Canna Lilies are originally from the tropical Caribbean, most varieties just can’t handle a chilly Central European or North American winter outdoors. For most of us, that means digging up the rhizomes in the fall and replanting them once things warm up the following year.
When is it safe to plant Cannas?
As I mentioned, Cannas are definitely not winter-hardy. They really despise frost! Because of that, you shouldn’t move them into your garden beds or outdoor containers until you’re sure the overnight freezes are over. A good rule of thumb is to wait until after the “Mother’s Day” frost window in May. Keep a close eye on your local weather forecast to find that perfect frost-free window.
Hardening off your started plants
If you’ve started your Cannas indoors early, you’ll need to “harden them off.” This just means gradually getting those young plants used to the cooler outdoor air. I recommend putting them outside during the day when it’s mild, but definitely bring them back inside at night so they don’t get zapped by a surprise late frost.
Finding the perfect spot
To get those big, beautiful blooms, picking the right location is key. Here’s what your Cannas are looking for:
- Full sun to partial shade
- Protection from strong winds
- Nutrient-rich soil
- High organic (humus) content
- Good drainage
Cannas are particularly happy in slightly acidic soil with a pH level between 5 and 6.
How to plant the rhizomes
Now, how deep should you go? A good rule of thumb is to plant the rhizomes at a depth of about two to three times their diameter. Space them out at least 20 inches (half a meter) apart. You’ll want to give them that same amount of “elbow room” from any other plants in your garden, too, so they have plenty of space to spread their leaves!
