Broad Beans Leguminosae, Vicia
Place of origin : Central Asia 〜 Mediterranean coast
Optimal temperature for germination 70°F (20℃)
Optimal temperatures for plant growth 60-70°F (15~20℃)
Characteristics Scientific name: Vicia fada
Broad beans like a slightly cold climate. Young seedlings can tolerate coldness, but as seedlings grow, they become vulnerable to coldness and their development suffers. (In the early spring, after branches begin to extend, plants can get damaged by slight frosts.) Also, the plants are vulnerable to heat and can’t grow well when the temperature goes up to 80°F (25℃) or more.
As plants are vulnerable to dry conditions and need a plentiful supply of water, a deeply tilled field is appropriate. In order to flower and produce beans, plants need low temperatures (about 32-35°F, or 0-3 ℃ ) during their seedling stage. According to the zone, seedlings are sometimes exposed to low temperatures artificially through refrigeration after they germinate.
In warm, moist soil, many seeds tend to decay.
Therefore, you should avoid seeding during heavy rains. For proper planting times please consult the USDA Hardiness Zone Map for your area. In a case of broad beans, sow seeds with their black line obliquely downward and cover the seeds with ½” to ¾” (1-2cm) of soil. Sow 2 seeds together in ridges spaced 30”-40” (80-100cm) wide with 12” to15” (30-40 cm) between seeds. For transplanting seedlings, grow seedlings in pots and then plant the seedlings after the cotyledon appears (before 3 leaves develop) one by one on the ridges.
The seedling that survives winter should be small than this one. (The seedling with 4-5 leaves after the cotyledon)
When a few leaves develop after the cotyledon, thin and grow the remaining seedlings.
If the space between seedlings is tight, don’t pull the seedlings, but cut the seedlings.
Gathering soil around base of seedling
In early spring, when the seedlings begin to grow large, gather soil around the base of the seedlings.
Bud picking/Training of branches/Thinning bud and branches
In cases where plants grow thick and stems are overlapping,
When plants become 15”-20” (40-50 cm) high, pick buds and train branches so that each plant has 5-6 branches. (By picking buds and training branches, plants can get full sunlight and have good air circulation.) In cases where the flowers and the pods are too numerous, if the extra pods are removed early, later in the season large-sized pods can be harvested. Also, after the flowers that are able to produce beans blossom, the remaining pods growth can be hastened by thinning the buds and the branches above the flowers. (Also the number of the pods that decay before they enlarge will decrease.)
Depending on when the seeds were planted, the time to harvest is after the pods enlarge and the back of the pods become black. If the proper time of harvesting is missed, the beans become stiff and the beans will taste bad. The pods should be harvest while they are shiny.
Seeding and growing seedlings in a low tunnel.
When seeding is delayed because of temperatures, sow seeds and grow the seedlings in a low tunnel sometimes made from plastic. However, even during winter, temperatures can sometimes rise quickly, and plants may suffer from high-temperature injury. So, the temperatures will need to be monitored.
Large seedlings become vulnerable to coldness. In warm places this is not a worry, but in cold places overly large seedlings need to be monitored because they are vulnerable to the cold.
Large seedlings damaged by low temperatures.
Thinning of buds and branches of broad beans are necessary in order to harvest large beans. Most broad beans are produced on the lower part of plant. The beans at the top are small. For large, same-sized broad beans, thin buds and branches. Leave the leaf above the last pod to be harvested and remove the upper part above the leaf.
Pods on tip of plants may die due to the heat before getting ripe, so each pod should be large after thinning buds and branches.