African Iris care is pretty simple once your plants are well-established in your landscape.
They’re classic selections for your landscape that are known for being problem solvers, which we’ll get into shortly.
This post will cover the general care requirements for African Irises (also known as Fortnight Lilies) of the Dietes family, particularly Dietes Bicolor and Dietes Iridioides.
Read along and learn how to set your plants up for success!
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Suitable USDA Zones
The first thing to consider with African Iris care is, will they grow in your zone?
Unfortunately, Fortnight Lilies are not very cold-hardy. They come from a hot environment and they just aren’t suited for colder zones.
Therefore, only gardeners in USDA Zones 8 through 11 will be able to grow these Lilies as perennials.
Gardeners in Zone 7b can try to plant them in Full Sun in a spot next to some sort of structure where they will be protected from freezing winds during the winter. But, no promises.
If you’re in Zone 7a or below, you could plant them as annuals. But, in my opinion, these bloomers don’t make good annualss. They need time to grow into the landscape to reach their maximum bloom potential.
African Iris Care: Overwintering
Since they only grow year-round in warmer zones anyway, overwinter protection isn’t usually necessary.
Gardeners in USDA Zones 8a and 8b should consider covering new plantings overnight during hard-freezes in their first winter.
If they’re planted next to some sort of structure or if they were planted the spring before this winter, chances are that they’ll be fine.
If they were planted in the fall or they’re planted in an exposed area, they will be more vulnerable to the winter cold.
You can also try piling pine straw around the base of your plant to protect it from the cold over the winter. Remove the extra pine straw insulation in spring when warm weather returns.
Sun Exposure
African Irises need plenty of sun to grow and bloom properly.
Plant them in Full Sun or Partial Sun exposure.
6 to 8 hours of direct sun is great for most areas.
If you’re planting them in Partial Sun, shoot for at least 4 hours of direct sunlight. If you don’t, they may survive, but they won’t have as many blooms or as abundant foliage.
How to Water Your African Iris
Remember how I mentioned earlier that African Irises are problem solvers?
The great thing about them is that they’re lenient when it comes to watering.
It’s hard to water them too much, especially when they’re first planted.
They’re actually capable of surviving in standing water, which is not a common trait among landscape plants.
So if you have a spot in your yard that floods frequently or consistently holds water after it rains, try some Fortnight Lilies.
Do keep in mind that they are not salt tolerant. So they won’t grow well in areas that frequently flood with saltwater.
Watering New African Iris Plantings
Water your newly planted African Irises 2-4 times per week, depending on how much rainfall you’re experiencing in your area.
Twice a week if you’re receiving rain a couple of times per week.
Water four times a week if your weather is consistenly dry.
African Irises are actually drought tolerant once they’re fully established in the landscape.
But they will struggle, and they may not root as well, if they don’t receive enough water for their first growing season in your landscape.
African Iris Care: Soil Requirements
Fortnight Lilies are tolerant of many soil types and qualities.
But for optimal African Iris care conditions, plant them in fertile soil that is rich in organic matter.
They grow well in loamy soil. Loam contains sand, silt, and clay. This creates a rich soil composition that holds just enough moisture and contains plenty of nutrients for the plant to absorb.
Soil pH
African Irises aren’t overly picky about soil pH.
A soil pH between 6.1 to 7.8 will work fine.
When to Plant African Irises
Spring and Fall are the best times to plant African Irises.
If your area generally has mild winters with few, if any, freezes, Fall is the ideal time to plant them. This will give them time to get established in your landscape before the intense summer heat.
If you live in an area that does experience regular freezes during the winter, plant in Spring. This way, they’ll be more established when winter comes around.
Wrapping Up African Iris Care
African Irises aren’t difficult to take care of. A little extra care when planting will make all the difference.
Follow the guidelines listed above and watch your Fortnight Lilies thrive in your landscape!