Agapanthus is one of the few plants I can think of where the word “regal” is well and truly fitting. You have a plant with a full crown of emerald green leaves, spilling like a fountain from the center. Amid that crown, tall, sturdy scepters of green jut toward the sky, ending in globes of stunning purple or white flowers.
Regal, by all means.
It’s no wonder, then, that many walkways and entrances to homes are guarded on each side by beautiful agapanthus. This stunner from South Africa has made its way into gardens all over the world, and it’s easy to see why.
Agapanthus, African Lily, Lily of the Nile, all of its names evoke a sense of nature’s nobility. It comes as a bit of a surprise, then, that such a fancy-sounding and looking plant is so easy to grow.
A Surprisingly Simple Perennial
Here in the US, agapanthus is hardy in zones 8-11, with a couple of cultivars that can thrive in zone 7. The rest of us can easily grow agapanthus in containers or simply lift the rhizomes each year and replant them again in the spring.
Despite their looks, agapanthuses are quite tough.
They don’t need to be divided often, preferring to be slightly crowded and will happily bloom and grow without much fuss each year. They need plenty of sunshine, a full 6-8 hours of direct sunlight a day. As far as soil goes, as long as it drains well, they aren’t too picky. They are heavy feeders, but you can easily take care of that with a fertilizer meant for tomatoes or blooming plants.
Agapanthus is drought-resistant once established and can stand up to windy summer storms. You’ll even find them growing on beaches, marching steadily across the dunes or in rocky outcroppings near the sea.
In some areas, they’re so easy to grow they’ve become a nuisance and are considered invasive. (If you’re looking to grow agapanthus, you’ll want to check to be sure that’s not an issue in your area.)
The Key to Consistent Beautiful Blooms
However, if you want those big regal blooms every year, then you’ll need to keep up with one simple gardening task – deadheading.
Oh, goodie, everyone’s favorite perennial chore to hate.
The Big ‘Why’
Deadheading agapanthus is especially important. Like many other blooming perennials, while you’re enjoying this year’s blooms, your plant is currently working on next year’s.
That’s right, all the blooms you’re currently enjoying this year started last year. How? By storing all the nutrients that the plant needs before dormancy.
Perennials that store up nutrients for next year’s growth in organs underground are called geophytes.
You’re probably already familiar with a few – tulips, daffodils, and a Christmas favorite – amaryllis. All of these plants use their leaves like solar panels to take in energy. That energy is used to take up and store nutrients in the storage organ growing underground, kind of like a battery – a bulb, tuber or, in the case of agapanthus, fleshy rhizomes.
If you don’t deadhead spent blossoms from your agapanthus, then that particular stalk becomes a drain on the plant, taking nutrients from next year’s flowers.
When growing flowering perennials, our goal is to ensure they bloom year after year. This is actually in direct contrast with the plant’s natural tendencies. The goal of any plant is to ensure it produces as many ways possible of reproducing itself before it dies or goes dormant for the season. For an agapanthus, this means spreading underground via its rhizomes and producing seeds to create new plants. So once those flowers are done, the plant will dump remaining energy reserves into creating seeds from them.
Remember our solar panel and battery analogy?
Leaving spent blossoms on your agapanthus is a bit like leaving the lights on in an empty room in your solar-powered home – it’s a waste of energy. However, if you turn that light off, you will suddenly have more energy in your reserve for other things. In this case, putting out more blossoms this year or saving up nutrients for big, beautiful blooms next year.
With that in mind, you can see the importance of deadheading your plants.
Easy-Peasy Deadheading
There’s no need for a long-winded tutorial. Deadheading agapanthus is quite easy. Use a clean pair of secateurs to snip off the spent bloom and stalk as close to the crown of foliage as possible. Compost the spent blooms, and you’re done.
Keep an eye on your plants and deadhead spent blooms as needed from mid-summer until they finish blooming in the fall.
A Reason Not to Deadhead
Of course, all that being said, there’s a perfectly good reason not to deadhead your agapanthus – the seeds mentioned earlier. If you would like free volunteer plants, then by all means, leave a few or all of your spent flowers to go to seed.
The dried seedheads offer a bit of structural beauty in the winter garden as well.
Why You May Not Want Your Agapanthus to Self-Seed
While you certainly can leave your agapanthus flowers on the stalk, there are a couple of things you need to know first. As I’ve already mentioned, agapanthus can be a bit aggressive when they spread. If they’re quite happy in the spot you’ve chosen to plant them, they will continue to self-seed in that area, spreading where they could encroach on other plantings.
The other reason you may wish to stay on top of deadheading your agapanthus is that the resulting volunteer plants will likely not breed true to the parent plant. Most agapanthus cultivars available these days are hybrids.
The seeds will lose many of the characteristics the parent plant was bred for. The volunteers may not be as prolific a bloomer, or the flowers might be smaller or a different color. Of course, if you’re not fussed about that, then having a gorgeous flower like agapanthus volunteer around your flower beds without any extra effort on your part is a win.
I know deadheading flowers isn’t anyone’s favorite gardening job, but at least now you understand there’s a good reason to keep on top of it when it comes to agapanthus. The nice part is their size makes the job much easier and less fiddly than deadheading something like petunias. With a little extra effort, you’ll be enjoying gorgeous blooms all summer long, knowing you’re investing in next season’s agapanthus blossoms as well.
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