Q & A
Guy Barter answers your seasonal questions and solves common plot problems
RHS May
The flowers on my apples seem to have stopped opening and the petals have formed a little brown cap. What is this, and will they recover?
This sounds like apple blossom weevil that has made something of a comeback in recent years as growers apply fewer pesticides. It has always been a problem for organic growers and before the 1950s was apple growers’ worst problem insect.
The weevils emerge in late winter and early spring grazing on buds and lay eggs in the buds. The larvae eat inside the flowers which ‘cap’ and fail to develop. The flowers won’t from fruits, unfortunately. The damage is tolerable in years with abundant flowers but can mean no crop in less fruitful years. The adults emerge from the capped flowers and spend winter in leaf litter ready to begin the cycle anew in spring.
It is sporadic, often occurring near hedges and does not affect some apple varieties. Where it does occur the only remedy for gardeners is to spread a sheet under the trees and tap the branches with a stick before flowers open. With luck the adult weevils will fall onto the sheet to be collected and destroyed. This may need doing several times.
My leftover carrots have started sprouting – is this normal?
Yes, carrots are biennial and form roots as a storage organ in the first year and then use the sugars in the roots to support flowers in the second as long as the roots survive frost overwinter. Other biennial vegetables include celery, leeks, onions and parsnips.
The carrot flowers are rather lovely being airy and light and are good for arrangements or for garden decoration. They are also very much appreciated as a source of nectar and pollen for insects. In fact some growers plant spare roots in early spring near their fruit trees to help support beneficial insects that will prey on the many unwelcome insects that can spoil fruit. They flower after the fruit bushes and trees so won’t compete for pollinators.
You can save seeds but seeds from F1 hybrids might not produce worthwhile progeny and carrots interbreed so won’t be true to type if any other carrots are flowering nearby.
I sowed red onion and brown onion seeds in April. The brown ones are growing well but the red onions have not come up – do they need any special treatment?
That is surprising as well as disappointing as all onion seed of any type should perform in the same way. As your brown onions emerged and grew well it se
