The Canna lily is a very popular plant here in the south due to their heat tolerance. It is coincidentally the favorite food of the Canna Leaf roller ! Just kidding. It is like the “host” plant of this caterpillar and will subsequently be attacked by it wherever it grows.
They are easy to grow and seem to flourish and multiply with little care. They look great in flower beds planted in mass or along a wall. Canna Lilies bloom from Summer to Fall in zones 8 to 11. That means from Georgia to Florida. Though with this warm weather everyone is having, I’m sure they do great much further north.
Canna Lily Requirements
Canna Lilies perform best in full sun. Like most plants, we are told they “do well in rich organic, well drained soil”.
Hey! Who has that? Certainly not me.
In my experience, they will grow in relatively poor soil and will do very well in moist areas. My grandmother’s old house had a ditch behind it that stayed wet all the time. The Canna’s growing there along the banks of the ditch seemed to do very well in a very wet location!
The ones in my yard are growing in a sand and clay combination near my home’s foundation and are doing great!
Canna Lily Use
Their brilliant red, yellow, or orange flowers stand out in the landscape. They can bring a tropical look to a backyard or poolside. They can be grown in beds or do equally well in containers as your “thriller” piece.
Growing Canna Lilies
Canna Lilies will spread throughout your flower bed through rhizomes if you leave them in the ground all year. You will need to divide them every few years to keep them looking their best and not overcrowding.
If you live further North, the colder weather may require you to dig up the rhizomes and store them for the winter so as to not lose these beautiful plants due to freezing. This digging up during the cold months will also help prevent the spread of Canna Lilies.
Canna Lily Growth Habits
Most get about 4 feet tall and if you’ve ever owned one, you know once they get any taller, that they are prone to fall over with the slightest breeze. This may require staking or netting unless you decide to cut them back early.
You can dead head the flowers once bloomed and turning brown to keep your Canna Lily blooming all Summer and well into Fall.
I really enjoy my Canna Lilies every year. A few years ago, I transplanted some beautiful dark bronze leafed Canna Lilies from my Grandmother’s old flower bed. Though I am not sure what they were called back then, I have seen them in nurseries here recently and they call them “Black Canna Lilies”. They are absolutely gorgeous when they first come out of the ground.
Once they bloom they are even more spectacular.
Be warned. All of this beauty can be ruined in a matter of days without some extra care and a good eye.
What is a Canna Leaf Roller?
There is a little brown butterfly called a Skipper that will ruin your day. They look like a moth but are technically a butterfly. You’ll see them skittering about, laying their eggs very quickly all over your Canna Lilies.
The leaf roller is the resulting offspring.
I’m all about butterflies and promoting pollination in the garden but the Canna Leaf Roller is the bane of many a gardener.
Canna Leaf rollers start out as tiny yellowish caterpillar. Like all caterpillers, the canna leaf roller will grow very quickly. As it gets larger, it becomes almost translucent in appearance.
Canna Leaf rollers will use tiny strands of a silk like substance to tie the leaves of the Canna Lily together and eat them from the inside out. Leaving behind an ugly tattered leaf filled with caterpillar poop.
This is a massively effective tactic to protect the caterpillar from predators. Therefore insuring they eat as much as possible, as quickly as possible. This means disaster for your Canna Lilies.
If you catch them early, which is dang near impossible without checking them every single day, you can keep Canna leaf roller damage to a minimum.
Once there is alot of canna leaf roller damage though, there is no choice but to cut off the damaged ones. If an entire plant is chewed up, it is best to cut it all the way back to the ground.
This will not hurt the plant at all and may even revitalize growth. If done early enough in the season, as late as October where I am, they will still have time to grow back and flower.
Preventing Canna Leaf Rollers from Overwintering
Any pruning done to get rid of leaves or plants damaged by Canna Leaf Rollers must be disposed of and not composted or left near the plants. Also when the plant dies back in Winter, it should be pruned all the way to the ground.
Reason being, the Canna Leaf Roller larvae will overwinter in the dead leaves and stems and will emerge in Spring, ready to wreak havoc once more!
Treating and Preventing Canna Leaf Roller Infestation
There are a couple of ways to thwart these pests. Knowing what kills canna leaf rollers is the best way to start controlling them.
The first basic way is to inspect the leaves and look for the caterpillars and remove them by hand. Problem is, these guys are extremely difficult to find if they aren’t already the size they would be if they have eaten enough of the plant to cause irreparable damage.
The other is with chemicals. No one really likes to use too many harsh chemicals in their garden. There’s malathion, and byfenthrin to name a few. They smell horrible and will kill many other beneficial insects.
Another way to go, which is best in my opinion, is to use any product with the Baccillus Thuringeinsis bacteria, or BT for short. It is based on a naturally occurring bacteria found in soil that effects the digestive system of the caterpillar. It takes a couple of days to see results but it’s very effective and mild on most plants.
Spinosad is another newly released bacteria based pesticide. It’s effects are supposed to last 5 days or more. It provides a much longer lasting solution that works in much the same way as BT.
I’m going to assume you’re going the highly effective, more environmentally friendly organic route.
When you mix the bacteria in water as directed on the product package, make sure to shake up your sprayer regularly as you apply.
I always set mine to a fine mist so it covers widely and lightly.
As you spray, it will seem to bead up and roll off most plants that I’ve ever used it on but there’s enough staying on it to do the job.
Baccilus Thurengiensis will degrade in sunlight so it’s best to apply late in the evening. That’s the time most caterpillars come out to eat anyway.
Make sure to spray the underside of the leaves thoroughly. Spray into the newly formed leaves that may still be curled up. There’s no need to spray the flowers.
Rain will wash it off and you’ll need to reapply regularly for it to be effective, as with many pesticides.
This is a really time consuming part of gardening but if you want to keep your Canna Lilies looking their best, it’s a very necessary job for most people growing then.
I hope these guidelines help you to keep your Canna Lilies looking their best!