Asparagus beans flourish in the summer heat. Plant them after all danger of frost has passed.
Asparagus bean seeds sprout and grow best in warm weather, and need a long, warm growing season (at least 75 days of frost-free weather). Plant seeds in loose and well-drained soil. Choose a spot that gets full sun; some afternoon shade in hot summer areas is okay. Don’t grow where legumes (peas or other beans) have grown the previous year. Beans don’t need overly-rich soil, but appreciate some extra compost at time of planting.
Beans, as a general rule, should be direct sown in the garden. The root systems of beans are shallow and grow best when undisturbed. Plant seeds 1 inch deep with the ‘eye’ facing down. Space beans 3-4 inches apart.
Asparagus beans are happiest when growing up, and will easily climb 6 to 8 feet or more. Plant bean seeds at the base of a trellis or cattle panel with plenty of straight vertical supports. Put supports in place at planting time to avoid disrupting roots of growing plants. Allowing beans to grow vertically makes harvesting easier, and keeps the plants healthier and less prone to being eaten by critters.
Although called “yardlong” beans, harvest the beans when they are between 10-12 inches long for best flavor. If the pod becomes soft or spongy, you’ve waited too long; the beans inside the pod are developing and the pod’s flavor changes.
To harvest the beans, twist the bean off the vine rather than pulling. Asparagus beans are usually produced in pairs at the terminal bud. Twisting off the beans will leave the vine intact and ready to produce more beans.
Noodle beans grow fast and should be harvested often. Keeping beans picked encourages more production. Leaving plants on the vine signals to the plant that its job is about over, and it slows down production.