Perennial plants that originate in South Africa, but many hybrid forms are now available providing the potential to have a display of Agapanthus in the garden or pots from late June through to the frosts. They divide into two groups, but it is not always apparent where the divide lies! Do be aware of what your growing conditions will be so that you choose the right variety for your particular aspect, soil, latitude and altitude. All factors to take into consideration.
Most importantly they are sun lovers. They are also very drought tolerant, but do often perform better in wet summers and if the soil is good they will make huge clumps. New flower buds are formed the previous autumn so they flower better after a long damp autumn. There are probably hundreds of varieties to choose from and of these it would probably be no loss if half of them disappeared! They should be with you for years so apart from hardiness select your purchases by colour, height, form of the flower, abundance of flower and flowering time. Well established plants only need further division when flowering diminishes, they are very versatile, ideal for seaside gardens are not palatable to rabbits and relatively unaffected by slugs and snails.
The evergreen forms derive from plants from milder and wetter parts, they tend to have broader and fleshier leaves and because they keep their foliage through our winters they require some protection. At the other end of the scale the deciduous forms tend to have narrower foliage and shed their leaves before the winter so they are considerably hardier. All the same, it is still worth mulching their ‘crowns’ with something in the late autumn – if this is soil-enriching manure all the better as they are hungry feeders, and therein lies the problem for plants in pots - the restricted root run is fine whilst there is some nutrition available, but when the compost has been depleted of nutrients they will not flower. Also the compost in pots suffers more from freezing and thawing than the soil at any depth unless you provide some added protection during the winter. There is a trial in progress at RHS Wisley of the hardy forms of Agapanthus which might be worth a look?
There is a new pest of Agapanthus that we are being told to look out for, the Agapanthus Gall Midge, so new that it has yet to be properly named. It is uncertain yet whether this is just going to be an annoying pest that we are going to have to learn to live with, or how devastating or manageable it might be. But I feel that is a case in point for better biosecurity on imported plants. There is scant information anywhere about it, just type in Agapanthus Gall Midge to find out what all there is.
The indication as to whether plants will be supplied from pots or from division is offered as a guide only, it cannot be guaranteed upon. Plants from division (ones which we have divided from bigger ‘crowns’ dug on the nursery) might take longer to become established in the garden and to flower well, they may take a year to settle in. But after a year plants from division and plants from pots will be very similar, all other things being equal.