Now that flower spikes are actually starting on the radish plants, a couple of questions have come up:

1) 'Turnip'-like roots. The radishes do produce a large white / green root that can look remarkably turnip-like - don't worry! This is normal, as once the flower spikes get going the plants often lose most of their leaves. The big root supports the flowering and seed production, although it isn't edible.

2) Tall flowers. The flower spikes on the radish plants get get pretty tall, and may need a full-length garden cane to support them. But this doesn't mean you need as much fleece to keep the bagged plant covered as you might think, as the flowers will still only be open at the top of the plant, and you do not need to cover the leaves at the bottom. The photos below show how to move fleece up the plant as they start to stretch up:

Bagging the radishes
Left to right - a tall flower spike; you only need to cover the flowers; gathering the fleece just below them is fine.
Bagging the radishes

So your radishes may well end up with a rising hat as they get taller!

3) Pests! At this stage the radish leaves should be pretty resistant to slugs and snails (although they will probably still have a go at damaged or dying leaves), but because it has taken a while for the plants to actually get going this year, this means they are at risk from cabbage whites and other butterflies that lay eggs on brassicas. If you start to notice little holes in the leaves like those below:

Little holes in the leaves of radish plants, especially where it looks like the surface has been scraped away.
Caterpillars! These are quite easy to see and pick off though, so they shouldn't be too much of a problem.