Yesterday I planted out a flat of beans that I had sown in paper pots on July 22. I've found that I have much better success at getting the beans to germinate and survive their first few days of life if I start them in the pots. This method works well when the garden soil is still cool which makes the seeds prone to rotting, I keep the flats indoors at night and put them outside on sunny days. At this time of year I keep the flats outside through the entire germination period. Once the beans have germinated and the cotyledons start to emerge from the soil it's safe to start planting them. I don't have as many problems with rotting seeds at this time of year but the sowbugs seem to love germinating beans and I have fewer losses to them when I plant out paper pot beans.
Here's a view of the flat at planting time. The seeds were sown into ordinary bagged potting soil with nothing else added other than some Rhizobium innoculant to encourage the formation of nitrogen fixing nodules on the roots. It's important to get the beans into the ground before they get too large to minimize root disturbance.
You can see that the roots are barely starting to poke their way out of the bottoms of the pots and the plants are starting to unfurl their first true leaves. Some of the pots look like they are duds, but I actually got 100% germination in the flat. I planted out each pot, I've found that the plants that haven't pushed their cotyledons out of the soil yet will do so very quickly after planting them out.
I plant the whole pot just deep enough to cover it completely and am very careful not to disturb the roots. Water the pots in gently rather than pressing the soil. The roots will grow through the paper into the surrounding soil and the paper will eventually rot away. Here's the patch of newly planted Rolande bush filet beans.
And this is a planting of Neckarkönigin pole snap beans. Both new plantings got covered with floating row cover which I find necessary to keep the rodents from gnawing on the tasty new bean sprouts.
It was 10 days from sowing to planting out and I could have planted out a day earlier. It's really easy to end up with a flat of overgrown seedlings (trust me, I've done it too many times) so now I always make sure to prepare a spot for the beans as soon as I sow a flat.
You can read more about how I make paper pots on one of my old posts HERE.