The blue or white flower balls of the agapanthus adorn balconies and terraces in summer. With these tips for overwintering, the exotic plant will bloom for years.
Agapanthus, also known as African lilies, is one of the most popular potted plants of all. The various Agapanthus species were already ubiquitous in the baroque residences of European kings and princes several hundred years ago. Not least because they are extremely robust and can grow very old with a minimum of care. An important point here is overwintering. Incorrect wintering is often a reason when the next year then the African lily does not bloom.
Agapanthus flowering usually begins in July and lasts until mid-August. This is quite a short period for a container plant. However, the splendor and abundance of the ornamental leek-like, spherical inflorescences more than make up for the short blooming period. Depending on the conditions that prevail in the winter habitat of the ornamental lily, it is not possible to influence the duration, but the timing of flowering.
Agapanthus species: Hardy or not?
Agapanthus, unlike most other potted plants, is not a shrub but a perennial that spreads by runners (rhizomes). Of interest to the gardener are mainly the deciduous Agapanthus campanulatus and the evergreen Agapanthus praecox and africanus. However, Agapanthus hybrids, i.e. cultivated forms created by crossing different species, are much more widespread in gardens.
While evergreen species retain their foliage in winter, deciduous ones lose their leaves. Some of the latter are conditionally hardy and can even be planted outdoors in mild regions. Like the potted plants, they then need a sunny and wind-protected place. In the cold months, protection of the African lilies is again necessary for overwintering in the garden. Evergreen Agapanthus need to move to winter quarters before the first frost. They are more accustomed to the mild coastal climate from their homeland and are not hardy in temperate cilmate.
How to properly overwinter African lilies?
Overwintering Agapanthus is actually not difficult. However, a few points must be taken into account so that the bloom does not diminish in the coming year. All Agapanthus hybrids, whether evergreen or deciduous, can be overwintered in a dark cellar. It is important that the temperature is well below 10 °C / 50 °F. If the location is too warm for the plants, they will hardly set flowers for the next season. Of course, a cold, but bright wintering is also possible. It has the advantage that the plants do not lose so many leaves in the winter and bloom earlier the next season. Sometimes even as early as May.
If you have difficulty finding suitable winter quarters, you should leave the plants outside as long as possible in the fall. In the spring, as early as March, winter out the African lily again. Agapanthus are used to light frost down to -5 °C / 23 °F from their South African homeland. It is important that the root ball does not freeze. If there is still a threat of late frost, it is best to pack the plants well or place them once again in a sheltered place. If you care for your African lily in the bed, it is best to protect it in winter with a layer of autumn leaves or bark mulch. This is especially important for freshly planted specimens.
When agapanthus has reached a container size that is difficult to transport to winter quarters, you can divide the plant like a perennial, and propagate the plant at the same time. Use a sharp knife to cut the root ball into more handy pieces, and then plant them in suitable containers. Use normal potting soil as a substrate, which you mix with a few handfuls of expanded clay. This will improve the water and air balance and at the same time the structural stability of the substrate.
What care needs African lily in the winter?
Agapanthus are basically quite easy to care for, especially in winter. While you should water the potted plants abundantly and fertilize them regularly during the flowering season, the need is greatly reduced during the winter months. This is especially true for the deciduous varieties. During wintering, water the plant just enough so that the substrate does not dry out. The cooler the plant is, the less it needs. Too much watering should be avoided at all costs, otherwise the roots will rot quickly. This also applies to care from spring to fall. From September onwards, you should no longer fertilize Agapanthus.
The leaves of deciduous varieties will slowly die before or during the winter. Do not cut them with scissors, however. Remove dried leaves by gently tearing them off.
When to repot Agapanthus after wintering
The African lily blooms most beautifully when the planter is fully rooted. However, you should repot the plant at the latest when the root ball pushes slightly over the edge of the pot. An extremely dense root system will result in Agapanthus not being able to absorb enough water. This does not necessarily manifest itself in the number of flowers, but the plant will begin to decline and no longer make any growth. Therefore, it is best to place the root ball in a new container after wintering in the spring. This should be only slightly larger than the old one. As a rule, the flowering in the repotting season is somewhat less. But already in the following year Agapanthus will regain its old form.