Last Updated on May 20, 2022 by Real Men Sow
These striking sun-loving border plants are prolific producers of large, round flower heads. They usually come in beautiful blue shades. They rise on tall stems that go above clumps of strappy leaves. Some varieties, particularly the evergreens may not be completely hardy. Therefore, they are best grown in containers that can withstand frost.
Before You Get Started With Growing Agapanthus
Choosing an agapanthus
There are many agapanthus varieties. It is important to keep these things in mind when choosing the right one.
- Agapanthus heights vary. Some are small (20-60 cm) and others grow to 1.5m (5ft). The shorter ones should be at the front as to be seen. The taller ones should be in the middle. Containers can be used to grow all sizes.
- The key is flower color. There are many shades like inky blue, pale sapphires as well as purples and whites. You can choose a shade that suits your plants and is compatible with them.
- The hardest and most difficult agapanthus are deciduous varieties that lose their leaves. Some agapanthus, mainly evergreen varieties, are tender and can be kept overwintered in cool greenhouses.
- Most flowers are rounded and have a trumpet shape. Some agapanthus species have pendent flowers in rounded heads.
- It is a good idea to buy hardy varieties in spring. Even though tender evergreens can be purchased at this time, they will require protection from frost.
- Potted plants can be purchased in flower during summer. However, it is important to water them regularly throughout the year so that they establish well.
- You should buy the plants in containers, not packets. The plant might have dried out and may not thrive.
All agapanthus should be grown in well-drained soil, in full sunlight. Shade is not a good place to plant them as they won’t bloom much.
Your agapanthus should be planted on the border in spring. If your agapanthus plants are in containers, you should plant them at the same depth as the container. The noses of bulbs and fleshy rhizomes should be covered with soil 5cm (2in). You can grow agapanthus indoors if your soil is susceptible to waterlogging or you live in cold areas.
Use loam-based soil to grow single plants in 20-23cm (8-9in diameter) containers. All container plants, tender or hardy, can benefit from winter protection.
How To Care For Indoor Agapanthus Plant
- It is important to water your plants regularly during the growing season, particularly the first year after they are planted. They will not need much water once established, but a little in the late summer in dry years will ensure that they flower well in the following year.
- When border plants begin to grow, feed them with a balanced fertilizer like fish, blood, and bone.
- Use liquid fertilizer such as Phostrogen, seaweed feed, to fertilize containers. Follow the directions on the bottle. From April to the time that flowers start to show color, feed fortnightly.
Deadheading and cutting back
- When flowers are dead, cut them at the base. This will encourage plants to bloom longer. However, some people like to keep the seedheads around for winter interest.
- The autumn is the best time to remove the yellowed and flowered leaves of deciduous plants. Evergreen leaves with tatty leaves can be removed at any time.
- You can protect your autumn potted plants by placing them in a sunny, frost-free area, protected from the worst winter rains. If you don’t have one, place the cold greenhouse or cold frame at the base of a west-facing wall. All agapanthus types (hardy and tender) can be wrapped in horticultural fleece, two to three layers thick, for protection from November through April.
- Winter protection is necessary for evergreens and tender plants. You can also cover the evergreen leaves with a few layers of horticultural fleece. In colder regions, the tender evergreen varieties can also be grown in containers. They can then be moved to a frost-free conservatory or greenhouse for winter.
- You can help plants survive winter in cold areas by putting a mulch layer 15-23 cm (6-9in) deep around them in autumn/early winter. The mulch should be removed in spring to encourage growth. You can use straw, sand or home-made compost for the mulch.
Propagating Agapanthus Plant
It is possible to lift clumps that are already established and divide them into smaller clumps. It is best to do this in spring (late March or April). This is the best time to grow more plants from a cultivar, as the new clumps will all be identical.
Agapanthus can also grown from seeds, but the result will be quite different from the parents. Each one will be different, so it is possible to find a rare one among the seedlings.
Problems With Growing Agapanthus Plants
Agapanthus can sometimes have difficulty blooming despite being very easy to grow. It’s disappointing to see agapanthus fail to bloom well, however, this is a very common problem that can be solved. Keep your plants well-watered from summer to early autumn for a great display next year. This will encourage the growth of new buds and promote flowering.
Agapanthus flowers aren’t better when they are pot-bound, contrary to popular belief. They like to be cozy in their pots and flower poorly if they are over-potted or over-divided. However, they will also hesitate to flower if they are too pot-bound. To improve flowering, you can pot up in a container 2.5 to 5cm (1 to 2 inches) larger every year. You will also need to water and feed them from spring through autumn.
Agapanthus can also fail to bloom due to too much shade, too cold weather, and insufficient winter protection. Too much winter warmth can lead to premature flowering but poor quality flowers.