15 April 2016

15 April 2016

how to sow broad beans and save summer bean seeds

Sowing broad beans

  • Broad beans are best grown in winter when they won’t get affected by chocolate spot. Chocolate spot can be damaging, sometimes causing flower loss, and stem infections may cause the plants to collapse.
  • Having free-draining soil is important for broad beans, so sowing them in a raised bed or a well-mounded one is ideal. If your bed doesn’t have good drainage, consider sowing the seeds in a tray then planting out seedlings.
  • Many people soak their broad bean seeds overnight before sowing, but Rob doesn’t think this is necessary due to the high moisture content in the soil they’re going into.
  • Like all beans and peas, broad beans like a slightly alkaline soil, so Rob dresses the bed with a handful of lime per square metre.
  • You might like to consider purchasing a soil testing kit to measure the pH of your soil so you can adjust the pH more accurately.
  • When sowing your seeds, make sure you get rid of any that have bits broken off, as these won’t germinate.
  • Broad bean seeds have a high germination rate, so you can position the large seeds exactly where you want your plant. Sow to the depth of the seed and about a hand-length apart. Simply push the seeds into the soil and leave. You don’t have to cover them over with soil.
  • Broad beans are not one of Rob’s favourite vegetables for eating, but he grows them because they’re so beneficial for the garden:
    – the nodules on the roots fix nitrogen in the soil
    – broad beans are a great green manure crop. Just dig them back into the soil for a real conditioning.
    – when you pinch the tips out to keep the plants bushy, you can use these tips in stir fries and salads
    – broad beans flower when not many other plants are flowering which brings in the bumblebees. Bumblebees need the pollen and nectar to build up their colonies.
  • A broad bean bed should be sheltered from strong winds because of the height they reach.
  • You can stake the plants when they grow tall, but Rob favours pinching out the tips of the plants as they grow, which encourages stocky, sturdy and self-supporting growth.

Saving summer bean seeds

  • Rob has left a few scarlet runner beans on the vine during the growing season specifically to use for seed saving in the winter. Alternatively, if you’re wanting the space to grow other crops, you can harvest them and leave in a dry spot. This is what we did with our Borlotti beans.
  • The job of saving bean seeds only needs to be done every 5 years or so. If you save your seeds well, they’ll last this long.
  • De-husk the seeds. The husks are a great carbon source for your compost.
  • The seeds now go in the freezer for 3-5 days BUT they have to have a moisture content of only around 7%. You can test this by striking the seeds with a hammer. If the seed smashes like china it’s ready to go in the freezer. If it’s soft and squidgy, there’s still too much moisture. If this is the case, dry the beans out further and test again.
  • The reason we put bean seeds in the freezer is to kill off any possible bean weevil infection.
  • After 3-5 days take the seeds out of the freezer, and store in the fridge, well-labelled, along with other seeds.
  • Use this method of seed-saving with all beans and peas.

Camera: Jarod Murray
Editor: Thomas Asche
Production equipment and post-production services provided by The Black Forest Breathes