View the Broad Beans page

02 Jul 23 Simone (Australia - cool/mountain climate)

I planted seeds a couple of weeks ago but no sign of germination. We are getting frosts most mornings in the upper Blue Mountains NSW. Am I too late? I heard they grow better from seed or should I try to germinate inside first?

Reply

03 Jul 23 Celeste Archer (Canada - Zone 5a Temperate Warm Summer climate)

Let's start with the germination temperature: 7c to 18c is the ideal germination temperature for FB, further the temperature needs to be sustained (over 5 or more days). So it needs to be warmish for the seeds to germinate. They will however happily reside in the soil until those temperatures are met (within reason- excess moisture causing rot etc.). The growing temperature for fava beans is between 4c and 24c. The kill temperature is -4c to -10c depending on the variety. What happens between the kill temperature and the grow temperature is a "waiting/holding" time (the plant is alive, but is sort of in limbo until the temperature is good enough again to grow). Above 24c the plant is starting to experience heat related symptoms and again is just holding on (unless the temps get to hot and kill the plant). You need to think about temperatures - what temps do you expect over the next month ? Based on the temperatures, do you think you seeds will germinate ? Then think about the grow temperatures -- if the seeds sprout will they be able to grow ? Generally if you want to grow fava beans in winter you plant them in late summer - so they germinate and grow enough BEFORE the cold weather -- during the cold weather (provided your are does not get too cold) the beans will be able to stay alive and grow a slight bit -- so you can harvest greens during winter and some beans -- then spring comes and the fava plants put forth LOTS of beans and then die. That is to say, the fava bean plant does not grow very much in cold weather and I find that typical of most plants that I want to over winter. They need to have a head start in decent weather and then they kind of SLOWLY inch their way to the finish line. Over wintering is a means of keeping the produce fresh - think of it this way - if you had produce in the fridge it is no longer growing, in fact it is in the process of dying, losing valuable nutrients daily. If you have a plant in the winter ground (that can handle overwintering), it is alive, GROWING REALLY REALLY slow, but it is alive and NOT losing nutrients. I guess what I'm trying to say is, super performance is generally not required, or expected, we are just looking to hold nutrients when we over winter. Clearly some plants are better for overwinter than others - in my area FAVA BEANS are a good choice.

Reply