These tips will help you keep your Agapanthus plants looking great.
Planting in the Garden – Agapanthus thrive in well-drained soil, in a sunny site that receives sun for most of the day. In heavy soils, mix in grit when planting to improve drainage, otherwise follow the instructions on the reverse of the label. Dwarf plants can be planted 30cm apart and larger forms 60cm.
Hardiness – Agapanthus have fleshy roots and leaves which can make them prone to frost damage. The hardiest of Agapanthus are deciduous, dying down in winter. They will survive most UK conditions once they are established.
Evergreen types are more tender and their leaves can be damaged by
frosts. Therefore, a mulch of straw or fleece is advisable when young
plants are establishing or extreme cold (below -5C) is forecast.
Established clumps of evergreen Agapanthus can withstand -10C to -15C
if the ground is well drained, but the number of flowers maybe reduced
the following summer. Planting in beds against house walls can reduce the likeliness of frost damage.
Growing in pots – Evergreen cultivars are especially suited to being grown in pots, allowing them to be brought into a conservatory or greenhouse for the
winter. Use a loam based compost like John Innes No3 with slow release
Miracle Grow granules added for long term feed. Liquid feed with Miracle Grow All Purpose Feed during the growing season. Overcrowded plants should be re-potted in spring.
Feeding – Agapanthus are quite hungry feeders so liquid feeding plants in
containers with Miracle.Gro liquid feed during the growing season is
important. A sprinkle of Sulphate of potash can also encourage flower
quantity and colour. Avoid giving plants too much Nitrogen or you will
encourage lush leaves at the expense of flowers.
Pruning – Flower stems should be cut down after flowering, unless you wish to
leave them for winter structure in the garden, or spray them silver or gold once dried as Christmas decorations.
Dividing and encouraging flowering – Plants that don’t flower or are over-crowded may be divided in late summer after flowering or in early spring. Large plants maybe pulled apart using 2 forks after lifting from the ground or removing from the pot. Agapanthus doesn’t like to be re-potted into pots that are too spacious as this will encourage leaf growth rather than flower production. Ideal conditions are provided where root development is restricted but the plants are well watered and fed through the growing season. The belief that flower production is maximised when the roots are climbing out of the pot is not correct.