Idea sent in by Steve Sow & Sow (Huntingdon) - July 2011
Here is a great idea for a nice little cash crop once early potatoes have been harvested from a grow sack. Simply sift through the soil and remove any remaining potatoes and roots, then pour the compost back into the grow sack and add a small amount of general fertilizer. Top-up the compost if need be and put in some quick cropping Dwarf French Beans (such as Stanley or Tendergreen), as shown below:
Ideally you should start off the bean seeds in pots, a couple of weeks before the potatoes are due for harvest, that way you can plant the seedling directly into the grow sacks for a good head start. However most quick cropping varieties can still be sown in July, so there is still time to pop some seeds in now. The great advantage of using a grow sack is that the sacks can be moved under shelter if the beans have not finished cropping before the first frosts arrive.
Dwarf beans do really well in deep soil that has a lot of organic matter so growing them in grow sacks is ideal and harvesting is much easier as the plants are raised by the height of the sack, so less bending down is required. I would recommend planting no more than four in a sack for the smallest varieties or just two plants if a larger variety is used.