If you’ve never grown canna lilies before, you might be a bit surprised at how readily they bloom.
All 10 plants in the Canna (KAN-uh) genus are capable of practically taking care of themselves.
They’re not actually lilies (or even related to them), but a few in your garden can make a statement just as impressive.
But if there’s one thing gardeners know, it’s that plants need to be fertilized to make up for the poorer soil quality in a garden.
What Is the Best Fertilizer For Canna Lilies?
Depending on your preference, either a 5-10-5 or 10-10-10 NPK fertilizer will work equally well.
However, there may be times when supplementing becomes necessary.
Cannas Aren’t Picky: Basic Feeding
Although they need some nutrition, canna lilies are known to bloom even when neglected, just like any other plant.
Unfortunately, if you want the most out of growing canna lilies, you’ll need to provide them with fertilizer.
Both 5-10-5 and 10-10-10 granular formulas added monthly in spring and summer work well, although they have slightly different application ratios.
When using a balanced formula, spread 1 pound per 100 square feet.
For 5-10-5, you’ll want to double that, spreading 2 pounds per 100 square feet.
This is because you want to have the same nitrogen ratio added to the soil regardless of which fertilizer you choose.
Avoid getting any fertilizer on the plants themselves.
If rain is expected in the next 24 hours, you can stop there, but if there’s no rain due, you’ll want to water your lilies with about 1” inch.
This helps introduce the fertilizer into the soil before breaking down from the sun’s rays.
You can also use a water-soluble or liquid houseplant fertilizer of the same NPK ratios by following the package instructions for dosage.
Getting Serious With Fertilizing
The fertilizers discussed above are just a bare-bones approach.
However, those serious about getting the most out of their plants will need more than one type of fertilizer throughout the growing season.
To truly get the most out of your cannas, begin with a 20-20-20 ratio fertilizer on young plants.
Once they’ve matured or are about to bloom, switch to a 15-30-15 ratio.
With these concentrations, you will only need to feed once in the spring before new growth appears and once again in the summer.
What’s In The Food?
There are several vital macronutrients your canna lilies will need to thrive and a wide range of trace micronutrients.
Here are some of the ones to watch out for and what they do:
- Calcium: As with humans and animals, calcium is an essential nutrient for general health and growth in plants.
- Iron: This important nutrient is a key component in creating chlorophyll.
- Magnesium: This is important to both chlorophyll production and a plant’s immune system.
- Nitrogen: A key component in creating chlorophyll and an essential resource for creating more foliage, this is the N in N-P-K.
- Phosphorus: A key resource for flower production that also removes excess potassium; this is the P in N-P-K.
- Potassium: This nutrient is vital to root growth and a plant’s immune system and is the K of N-P-K.
Imagine eating the same thing for every meal or having a single food for each season.
No matter how nutritious that one item may be, you’ll likely become deficient in a nutrient or have too much of a different nutrient.
Plants are the same way, and commercial fertilizers have a lot of chemicals, much like our own processed food.
As a result, consider giving them some alternative foods, either occasionally or in place of commercial fertilizers.
Some great options include:
- Coffee grounds are indirectly beneficial to canna lilies. They provide nitrogen digested by beneficial microorganisms if mixed with shredded leaves or a used coffee filter (the microorganisms help break down organic material, which becomes food for the cannas).
- Fish emulsion is a great organic food for plants and has a high nitrogen level.
- Organic compost is an excellent source of nutrients, especially nitrogen.
- Rose or tomato fertilizer is very close to what canna lilies would receive from the soil in their natural habitat.
Listen To Your Canna
Finally, it’s important to remember that fertilizing plants isn’t an exact science.
Like people, each plant has its own personality and quirks, so you may need to occasionally adjust the frequency or amounts of your feedings.
Testing the soil every 3 or so years is a great way to see what’s missing from the soil and what’s built up, allowing you to change the menu to balance out the existing food.
Plants have a language we humans can understand, and they will tell us through changes in their stems and leaves if they’re deficient in an important nutrient.
It’s up to us to listen and give them supplements in addition to their regular food as needed.