How to Grow Agapanthus

Last Updated: May 6, 2021 Approved

Agapanthus has beautiful bright purple or white flowers in abundance and is a beloved addition to many gardens. It's very easy to grow and will self propagate once established.

Steps

1
Choose the agapanthus. There are large and dwarf varieties of agapanthus, and differing flower colours from purple to white. Dwarf varieties can be used in smaller garden beds, as border edging, or in mixed garden beds.^{[1]
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2
Plant agapanthus in a suitable location. Ensure that there is plenty of space for it to bulk out. Part-shade to full sun will be tolerated by agapanthus. As the shade increases though, the flowering will decrease, so bear this in mind when selecting a spot.^{[2]
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- Most agapanthus have a moderate frost hardiness.
3
Prepare the soil. Agapanthus will tolerate most soil types. It grows best in good loam soil with some organic matter added (compost material).^{[3]
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4
Plant the agapanthus rhizomes. You can plant them in massed clumps such as a large garden bed or you can plant them in dense rows to create a line for a driveway or path.
5
Water regularly while establishing. Agapanthus can tolerate less watering than many other plants and can thrive in a hot summer.^{[4]
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6
Fertilise in late winter or early spring. Use a slow release fertiliser or pellets.
7
Prune. It is important to trim off the flower heads following flowering. Doing this provides the plant the best opportunity to store energy for the next flowering season the following year. It will also stop seeds from setting in your garden.^{[5]
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- Also take the chance to trim off dead leaves and stems.

Community Q&A

Question

Why are my plants turning yellow?

Community Answer

Probably too much watering or soggy soil. Reduce watering, or try adding a little sand to the soil.
Question

My agapanthus haven't flowered for nearly 4 years, but they are starting to multiply since I've fertilized and watered them regularly. Why are there no flowers?

Community Answer

It could be a number of factors. Sometimes perennials can become root bound and not flower as well. I would dig them up, divide them and replant.
Question

I have a large clump with about 10 separate rhizomes, should I separate? I heard somewhere that they like to be crowded, is that correct?

Community Answer

No need to separate as they grow equally well in clumps or separately. However, if you do wish to separate the clumps, they will again thicken up as the rhizomes reproduce.
Question

What time of year is best to plant Agapanthus seeds?

Community Answer

Late spring is the best time to plant.
Question

Will agapanthus grow outdoors in the Pacific Northwest? If not, will they grow indoors in a sunny location?

Community Answer

Agapanthus grow best in well-drained soil, in a sunny site that receives sun for most of the day. As long as you have that available, your plants should be fine. On heavy soils, mix in grit when planting.
Question

If my agapanthus were large clumps but are now a lot of little plants that get very few flowers, should I try to replant each one?

Community Answer

Remove each flower one by one and replant it. Make sure you remove it with a stem.
Question

My plants were planted this past spring. It is now October, and my leaves are turning yellow. Is this normal? I live in Alabama.

Community Answer

It is due to lack of nitrates and phosphorus. Try using fertilizer.
Question

Can agapanthus survive outdoors in a northern winter?

Community Answer

It depends on how far north. Mine survive, though lose a few leaves, through a southern English winter, with frost, rain, and occasionally snow, along with several days of harder frost (-5 to -10° C). In a place like Canada, however, I doubt many plants could survive the winter outdoors.
Question

Can I grow agapanthus from the seeds of the flowers?

Community Answer

Yes. You will need to plant them in the fall in seed trays, and then transplant the seedlings the following spring. It may take 2 years before they actually bloom.