Ask John Negus: your questions
Q
My bird of paradise plant is 25 years and has flowered every year despite never being repotted. I think it needs a new pot, but what compost should I use? Dorothy Loveridge, Old Basing, Hampshire A What a splendid Strelitzia reginae and how marvellous that it has performed so well. It would, however, certainly benefit from being repotted. If it has outgrown its existing container and the roots are pot-bound, reset it in a pot 8in (20cm) larger in diameter than its current one.
Start by using a hand fork to tease apart the rootball, especially if the roots are starting to grow in a circle. Then cover the new pot’s drainage holes with crocks or stones and fill it with 4in (10cm) of a mix, by volume, of three parts John Innes potting compost No3, and one part coarse grit.
Reset the rootball at the same depth at which it was previously growing and cover it with more compost. Gently firm it around the sides with a thin wooden ‘rammer’ to avoid air pockets.
Leave a 2in (5cm) gap between the top of the compost and the rim of the pot to allow for watering.
Ideally, cover the top of the compost with slate chippings to stop the compost ‘panning down’ when you water.
Bird of paradise plants hail from South Africa .They can only be grown successfully indoors in the UK, though if you live in the south you may be able to place them outside over summer before bringing them inside in autumn.
They usually take up to five years to flower for the first time, but your patience will be rewarded when they do.