Strawberries - straw

At what stage do you put straw under strawberries to keep them clean?  Do I do it now when they are just flowering which will keep the flowers up in the air and more available to be pollinated or only put it down when they are starting to form the fruit?

Best to get it down asap because the berries will form faster than you can act. Also, the plant will keep growing so doing it now is doubly useful. The next rain will pack down the straw nicely and all will be set for the berries to come.

Thanks, I'll do that tomorrow. 

I've got some strawberries growing in a mini grow bag.  Would I need to put any straw down - they are not actually touching soil?

The main reason I am using straw is to keep the strawberries clean by not resting on the soil and to prevent soil being splashed up from the rain.  I wouldn't think that you would need to do anything apart from protect them from birds, both the ones that fly and the better looking ones that go round in skirts/trousers!