Can I stop carrot fly attacking my crop?
Stephen Davis, by email
Arthur Braybrooke, by email
Terry says: You say you're growing your carrots in a raised bed and cover them with Enviromesh as soon as they germinate. If the crop is covered completely with this fine mesh then there's no way the adult fly can lay its eggs and the maggots attack your precious crop. These flies come in at ground level to lay their eggs so make sure the net is firmly anchored at soil level at all times. I put large boards at the base of my net to make sure it's firmly secured at ground level. I also cover the crop with a net when I sow, which gives that added insurance and also helps the seed germinate better.
Do you grow your carrots in the same raised bed every year? There's a chance that the fly has attacked your carrots in previous years and become trapped under the net as the maggots pupate in the soil over winter and emerge in May after you've sown and netted them. If this is the case, move the crop to a new bed where carrots haven't been grown before.
Stefan says: Epimediums are truly valuable rhizomatous, low-growing, ground-covering plants with spring flowers in shades of red, yellow and pink. They're naturally plants of woodland and I must admit that all the varieties I've grown have been highly tolerant of the dry conditions beneath trees in my own garden.
My favourite is the yellowflowered Epimedium perralderianum, which now carpets a large area in the shade garden, although like most species, it was fairly slow to establish and spread. It has lovely heart-shaped leaves that start life bright green but then gradually turn bronze.
I cut back all the old foliage in early spring before the new flowers appear – in fact, I cut it back at the same time as the foliage of the hellebores growing nearby. I then give a light top dressing with bone meal and leaf mould.
Among other kinds I have personal experience of growing well in dry conditions are yellowflowered variety Epimedium versicolor 'Sulphureum', Epimedium rubrum, with red and yellow bi-coloured flowers, and the lovely orange-flowered Epimedium warleyense.