Why do roses droop like this?

Any generic potassium sulphate or sulphate of potash will do. Westland, Levington et al fertilisers can be found in many garden centres, although more costly than the generic product.

 

I think our resident rose expert would agree with me when I say that Potassium will not help much, especially for the first round of blooms, as roses flower on the growth they make this year (well, the bush roses that most people have in their gardens do). Potash as it is also known by will help them later in the year & will most certainly help towards the end of summer as the new growth hardens & ripens to support the winter.

Proper pruning is what helps most - after buying varieties that don't droop in the first place!
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