Dividing Agapanthus Plants: When And How To Divide An Agapanthus Plant

Dividing Agapanthus Plants: When And How To Divide An Agapanthus Plant

By: Teo Spengler

Beautiful, easy care agapanthus plants are perfect choices to decorate the borders along your driveway or fence. With their tall, slender stems, lush foliage and bright blue or white flowers, agapanthus are about as attractive and low-maintenance as it gets. Another great thing about agapanthus is that if you have one, you can get extra plants free by dividing and transplanting agapanthus clumps. Read on to learn more about dividing agapanthus plants.

Can I Divide Agapanthus?

The answer is yes, you can and you should. As the plants mature, they crowd against each other underground, and this overcrowding limits their flowering. The best way to remedy the problem is to start dividing and transplanting agapanthus. But you’ll want to learn how and when to split agapanthus to be sure you do it right.

When to Split Agapanthus

Don’t think about dividing agapanthus plants while they are offering you those lovely blossoms, even if the flowering seems less than last year due to overcrowding. If you want to know when to split agapanthus, you’ll need to know whether your variety is evergreen or deciduous.

For evergreen varieties, you should think about dividing and transplanting agapanthus every 4 to 5 years. Do the actual division when new growth emerges in spring, or else in early autumn after the plants have finished flowering.

This timing works for deciduous plants too. However, these should only be divided every 6 to 8 years.

How to Divide an Agapanthus

Dividing agapanthus plants is easy. All you need is a garden fork or shovel, a large kitchen knife, and a new garden site prepared to receive the transplants. Here’s how to divide an agapanthus:

  • Press the garden fork or shovel into the ground just at the outside of the root ball of the plant. Pressing gently, lift the whole clump of agapanthus roots out of the soil.
  • Once the root clump is out of the ground, clip off the remaining flower stems right at the base, and trim off any old or faded leaves.
  • Divide the main clump into several smaller clumps with your big kitchen knife. Keep in mind, though, that the smaller the new clumps, the longer they will take to flower.
  • Before you start transplanting the clumps, prune back the foliage by about two thirds and clip back any dead roots.
  • Replant them in the sunny, well-drained location you have prepared for them, and irrigate them thoroughly.

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Read more about Agapanthus

How and when to divide perennials

Perennials grace our gardens year after year with their variety of brilliant colors and unique foliage forms.

After a few years in the garden, these perennials may start to produce smaller blooms, develop a 'bald spot' at the center of their crown, or require staking to prevent their stems from falling over. All of these are signs that it is time to divide.

Reduced plant performance may not be the only reason to divide perennials.

Divide and Transplant an Agapanthus

I have a huge agapanthus which needs to be divided and transplanted. I have never done this before. There must be 20-25 individual stalks. If I can get it out of the pot, how should I go about dividing the plants? Should I cut back the green stalks? They will probably go into shock and be wilted. Is this even the best time to do this at all? If it works, I will need several pots.

Late February or March would be the best time to do this. Or, when the weather cools down in the fall in late October or November.

I would purchase another pot the same size as the pot it is in. Remove the agapanthus from the pot it is currently in. It may help to run a large knife around the inside of the pot between the rootball and the pot.

Once out of the pot, divide the clump in half using the large knife. Be careful. Try not to cut through any plants (cut between them) - but it’s okay if some of the plants get cut through in the process. Don’t worry about cutting through roots in the process. Do not cut back the foliage. Two large clumps will bloom better than dividing the plant into many small clumps. Don’t plant the two clumps in pots any larger than the original pot. Agapanthuses bloom better when they have filled a pot with roots.

Then pot up half the clump in the original pot, and pot up the other half of the clump in the new pot. Use potting soil or potting mix. Place them in a shady location for a few weeks to recover and water as needed. Then move them to the locations where you want them to grow. That’s it.

Dan Gill
Consumer Horticulture Specialist

How and when do I divide agapanthus?

1 of 5 Blue agapanthus and red begonias ensure curb appeal. John Everett/Chronicle Show More Show Less

2 of 5 Close-up of agapanthus (lily of the nile) in a backyard water garden Jill Hunter/For the Chronicle Show More Show Less

4 of 5 Agapanthus in the Franklins' LaGrange garden. Carolyn and Travis Franklin/For the Chronicle Show More Show Less

Q: My 4-year-old agapanthus plants are crowded. When and how do I divide them? — A.M., Houston

A: Many find agapanthus blooms best when slightly crowded in a bed or slightly pot-bound, but often they do benefit when divided every four years or so. Dig the clumps in spring or fall: Carefully separate divisions with roots, cut the foliage back by half and replant.

Agapanthus tolerates full sun but adapts well in areas with winter sun and filtered summer sun or with morning sun and afternoon shade. These tuberous perennials thrive in a sandy soil enriched with humus.

Good drainage is important. Water well during the spring growing season, especially while the plants are developing flower scapes. Water moderately in fall and winter. Fertilize in early spring. After blooming, water well and fertilize with bone meal or superphosphate.

Kathy Huber has worked for the Houston Chronicle since May 1981. She was Features Copy Desk chief before becoming the first full-time garden editor for the paper in 1988. She writes a weekly garden Q&A and feature stories.

A Texas Master Gardener, she's the author of The Texas Flower Garden, published by Gibbs-Smith in 1996. She's been a frequent speaker at various garden events.

A native of Moultrie, Ga., she graduated from Queens University of Charlotte, formerly Queens College. She did graduate work through the University of Georgia system.

She is married to photographer John Everett and they have one son.

Extension Education in Travis County

Divide Agapanthus Now

It can take four years or more for Agapanthus bulbs (Agapanthus africanus), to multiply or naturalize.

Agapanthus are best divided and transplanted in the fall for spring blooms.

Eventually you’ll want to tackle large bunches and divide Agapanthus to ensure your lilies continue to produce those lovely blue or white bloom clusters. In the Austin area, these lilies bloom in mid-to-late spring, typically around Mother’s Day. As these are also great container bulbs, you can pot extras to gift to family and friends, or to enjoy on your patio.

Easy Dividing Technique

Grab your gloves, a spade, a hand spade or knife, and a watering can or hose for this activity. The easiest way to divide Agapanthus is to lift the entire bunch with a spade, digging in a circle around the bunch approximately 8-12 inches beyond the foliage.

The lilies develop a large mass of white fleshy roots which often travel as much as 16 inches beyond the foliage tips, but it’s okay to cut the roots for easier lift and transplant. The root system is typically no more than a foot deep, which is also why the roots develop a tangled web extending out from the foliage.

Once you have the bunch extracted, shake off the soil to expose the roots. If not too tight, use your hands to gently divide the bulbs into single shoots by pulling apart. If tight, use a hand-spade or knife to separate the bulbs, while paying attention to maintain several roots per bulb. Don’t worry if you accidently sever some roots, a single root on a bulb will maintain the bulb’s life.

Extracted Agapanthus bunch.

Separated Agapanthus bulb shoots.

Thinning Works Too

If you prefer to thin the plants rather than removing the entire bunch, look for a single or group of bulbs around the exterior and using a spade, make a slice in between the main grouping and that you’d like to remove. Remove as many bulbs or grouping of bulbs you’d like and then detangle into individual bulb shoots with your hands or by cutting with a spade or knife.

Bulbs Need Soil and Some Shade

Agapanthus grow in USDA zones 8-10 and require full sun to part shade while preferring well-prepared or composted soil. These bulbs can withstand a lot of water, but also do well with minimum incremental water during our times of drought. Agapanthus do best in our area with a little shade from the hot afternoon sun, such as the understory of a tree. For best blooming, ensure the bulb receives at least four hours of sunlight a day.

Once you’ve selected your spot, dig a hole twice as wide as the root system and only as deep as is necessary to sit the bulb so that the neck is slightly above the soil line. Build a small mound of soil underneath each bulb and spread the roots out in a circular fashion. After placing all the bulbs, fill in the soil and gently pat in place.

Spread roots in a circular fashion.

Keep bulb neck slightly above the soil line.

Water the entire area to give the roots sufficient moisture to recover from the shock of the transplant. Cut off damaged foliage so all the plants’ energy will focus on root development and sustaining the healthy foliage. With the cooler nights coming, add a layer of 1-2 inches of mulch around the bulbs to help protect the roots and to assist with moisture retention. Continue to water daily to every other day for the first week if no rain. After the first week, water every 3rd day for another week or two and then allow mother nature to take over.

Maintaining Agapanthus

In early spring, your bulbs will enjoy a little compost to help their continued development. Once the blooms have turned brown and the birds have enjoyed the seeds, cut the flower stalk off at the base. If desired, you can add a little bone meal or 5-10-5 fertilizer to help with the development of next year’s blooms. The strappy foliage is evergreen, so you will have the entire year to enjoy the mounds of greenery. New hybrids are being developed, producing bulbs with deeper purple blooms as well as new dwarf varieties reaching only 18 inches tall – so just another reason to enjoy an Agapanthus in a container or in-ground.

Additional Resources

Yvonne was a 35+year veteran in the computer and information technology industry when she retired and moved from Houston to the Austin area. In 2018, Yvonne certified as a Travis County Texas Master Gardener to follow her passion for gardening and volunteering within the community. She has spent 20+ years enjoying gardening and working with bulbs and perennials. She now tackles the challenges presented by the Austin area wildlife, drought, and limestone soil.

Care for Newly Transplanted Asparagus Plants

Treat your newly divided and transplanted asparagus like a brand new planting. Asparagus beds should be moist, but not soggy. After the soil settles, fertilize the plants with an all-purpose balanced fertilizer. Apply 1 pound of granular fertilizer per 100 square feet. Keep your asparagus bed weeded by lightly cultivating around the plants. Skip the harvest on the new bed for the first season to help plants develop the energy to deliver many future productive years in your garden.

Watch the video: Dividing Agapanthus