These vegetables are grown as annuals -- kohlrabi is a cool-season crop and yardlong beans and white eggplants are warm-season crops.
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Before planting the seeds, it's often a good idea to use a bean inoculant, a type of beneficial bacteria, in this case a bacteria known as rhizobia. Dampen the seeds with a light mist of water, then put the beans in a shallow tray. Sprinkle the inoculant over the beans, and stir to get a light coating of the powder on each bean.
Rhizobia are naturally occurring bacteria that help beans utilize nitrogen. Soils in which beans have been grown in the past usually have enough of the bacteria to make inoculant use unnecessary. But if you've never grown beans before, adding the inoculant will ensure that your soil has the bacteria that beans need to produce well. You can find inoculant at most garden centers.
Once the bean seeds have been dusted with inoculant, create 1"-deep holes in the soil, and place one bean in each hole. Put six seeds 4" or 5" from the base of each tepee pole, cover the beans with soil and water them in.
The beans should be up and growing in a little over a week. At this seedling stage, thin them so that there are two or three bean vines per pole.