Should I give up growing beetroot and spinach?

[Chris Graham]

I dont want to use chemicals but the problem with mangold fly (leaf miner) is terrible.

Not sure if there is an organic way of stopping this pest?  netting or fleece?

Any ideas?

[Chris Graham]

[Rhubarb Thrasher]

something else to worry about - i've never heard of them. Here is the advice from gardenaction

http://www.gardenaction.co.uk/techniques/pests/mangold_fly.htm
TREATMENT

Break the mangold fly's lifecycle at two  points. When any signs are noted, gently loosen the soil surrounding the plants with a trowel or hoe. This will expose the pupae to birds who love to eat them.

The second action is to remove any affected leaves immediately the damage is noted. It is possible to spray with strong chemicals but this is not recommended on health grounds.

[Chris Graham]

Yup seen that one, not sure if that would work well.

[valmarg]

I would have thought an application of thumb and forefinger nails into the blisters would be a quite effective organic method, unless there is a very large number of blisters. ;D

valmarg