The cultivation will effectively hold soil moisture for 30 days or longer, allowing for successive plantings over time with minimal effort. To ensure harvest continuity for staggered plantings, plant the next round of beans when the prior planting is in the “crook” stage , approximately every 10 days.When produced on a commercial scale, beans should always be planted to moisture rather than irrigated up. If you plant beans into dry soils and then irrigate them to initiate germination, weed seeds will germinate at the same time as the newly planted beans. In most cases weeds will quickly outcompete the beans and compromise effective weed management. It is not possible to cover labor costs, through sale of the crop, for hand weeding when weed pressure is high. See the publication Tillage, Bed Formation, and Planting to Moisture in this Grower Guide series for additional details. When planting to moisture, use a wide “Alabama” shovel mounted on the planter to run ahead and push off the dry dirt on top of the bed. Set the shovel so that it goes deep enough to get into the sub-surface moisture. When set correctly, the shovel leaves a flat “V” pattern down the center of the bed. On most soil types, as long as you can see some slight darkening of the soil that is exposed when the bed top is knocked off compared to the drier surface soil, there should be enough residual pre-irrigation moisture in the soil at the bottom of the “V” to initiate germination of the newly planted bean seed. Plant beans at the low point in the middle of the bed to conserve moisture deeper in the soil . In most cases 1–1.5” is a good planting depth for strong germination, growth rack although beans can emerge when planted 2” deep as long as the soil is “loose” and not compacted above the seed. Loose soil above the seed line also limits evaporative loss.

When beans seeds all emerge at roughly the same time, you know you have done a good job of planting them. Note that most bean planters are designed to drop seed into a small trench that is then covered with soil and firmed up with the planter press wheel. Avoid planting when the soil is too wet as the press wheel can create a compacted layer over the seed that dries into a firm crust, which can significantly impede successful bean seed emergence.When choosing a tool-bar-mounted planter for larger-scale bean plantings , select a planter that singulates the seed, has double disc openers that cut deep into the soil , and has a press/tamp wheel. Options include the Clean Seeder TP , the John Deere 71 “flexi” planter , and the International 185 planter planter. Note that on smaller farms, the cost of this type of planter can be a significant capital expense. Although no longer available new, the John Deere 71 “flexi” planter is still one of the more common planters used on the Central Coast for planting beans . It is called a “flexi” planter because it is designed to “flex” or “float” over heavy residue. This design feature makes it an ideal planter for planting beans following cover crop incorporation in the spring.The Clean Seeder TP and John Deere 71 planters have double disc openers that create a very narrow opening in the soi lFigure 2. The seed falls into the opening while the sides of the opening are being held open by the discs. The small trench created by the openers easily collapses once the disc openers pass. The press wheel on the planter firms the soil over the seed and helps to reestablish capillarity, which improves soil moisture movement from lower in the soil horizon. If you question whether there is adequate soil moisture, assess moisture early the next day after planting. Soil moisture typically improves overnight as a result of the light compaction created by the press wheel. The advantage of double disc openers is that they can easily cut through or roll over residual cover crop or crop residue.

In comparison, Planet Jr. planters use a fixed opener shoe, which gathers field trash when used to plant at depths greater than 1 inch. When residual crop residue wraps on a fixed shoe, it pushes soil away from the seed line, causing skips in planting and an uneven surface. Plate planters such as the Clean Seeder TP-TB, John Deere 71, and International 185 do an excellent job of “singulation” of the bean seed. Driven by the press wheel, the seed plate rotates in the bottom of the seed hopper. The holes in the plate allow single seeds to drop into the hopper cells. The cells rotate over an opening in the bottom of the hopper, and with the help of a “knocker,” drop the seed at a selected spacing as the planter moves through the field. Planting depth can be adjusted with a rotating cam on the side of the planter, which changes the angle of the press wheel in relation to the disc openers. Seed spacing is set based on the number of holes in the seed plate, as well as gearing, which is easily changed. Select seed plates carefully to match varieties, since bean varieties vary significantly in size and shape.When beans germinate, they lift the two seed halves above the soil surface. This is referred to as “epigeal” germination. The emerging beans will first push through the soil with the stem in a “crook” position and then the cotyledons will emerge, followed by the first true leaves as the hypocotyl straightens out following emergence. The early stage of germination when the stem first appears above ground is referred to as “in the crook” . Emerging beans are very susceptible to heat damage at the soil surface as they push upward. When planting in late summer , farmers in warmer inland valleys of California commonly put a “soil cap” on the bean seed line with small disc hillers . The hillers are attached to, clone rack and run directly behind the planter to form a small mound of loose soil directly over the seed line. During times of high daytime temperatures, growers dig up the embibed seeds daily until they see uniform radical emergence. They then mechanically knock off the cap. If timing is good, the beans will emerge through the soil during the cool of the evening, thus avoiding the issue of stand loss due to high soil temperatures.

In cooler coastal production areas you do not need to cap the seed lines. However, a very light soil cap helps keep the soil loose and moist. This can improve ease of emergence and stand uniformity in both extremes—when the soil is either slightly too wet or too dry.When soil moisture is optimal, planting to moisture allows the beans to germinate but limits weed germination, as most weed seeds require more moisture to trigger germination compared to the large bean seed. The beans emerge in a small trench in the middle of the bed, where vigorously growing beans will easily outgrow most weeds . Let the beans grow as long as possible without irrigation to allow them to root deeply and to minimize weed competition. In most climate zones on soils with decent water holding capacity, the beans can grow to full bloom before you need to irrigate . Once beans are 5–6” tall, do a first cultivation. Use a standard 3-bar cultivator with a set of reverse disc hillers running along each side of the plant line, side knives along the sides of the beds, and sweeps in the furrows. Run small chisels behind the tractor tires to a depth of about 4” to break tractor tire compaction and facilitate subsequent cultivations. This first cultivation will effectively terminate most newly germinated weeds from seed line to seed line. Then lay drip tape along the seed line. As the beans continue to elongate, use a rolling cultivator for the second—and most effective—cultivation. Properly set, the cultivator will gently return the dirt that was pushed off the bed top at time of planting to the middle of the bed . The bed should end up looking just like it did prior to planting. If bean stems are long enough, this “dirting” cultivation will effectively cover both the drip line and smother any weeds that have emerged in the seed line while covering only the lower stem of the bean plant. This last cultivation, or “dirting,” leading up to harvest is commonly practiced on large acreages of many agronomic crops that are planted to moisture in situations where herbicides are not used. To perform this cultivation successfully requires specific and tightly adjusted implements, and a significant level of tractor skill. As small farms scale-up to mid-sized farms and larger acreages, planting to moisture and dirting can significantly reduce the labor required for weed control.On small plots , you can easily plant beans to moisture by hand. Pre-irrigate your beds, and use hand tools to take out the newly germinated weeds. Push the bean seed into the deeper moisture by hand. Any subsequent weed growth can be handled with a wheel hoe or hula hoe. On larger plots , plant beans to moisture with simple tools. Use a rototiller following preirrigation to terminate weeds and form a soil or “dust” mulch. Form a planting trench with a small furrowing shovel mounted on a wheel hoe to access deeper soil moisture. Plant with a Planet Junior push seeder using the general purpose “deep” shoe, or the Jang large seed push seeder . On this scale, weeds can be managed using hand tools or wheel hoes.Time the first post-emergence irrigation based on subtle signs of water stress in the bean plants during warmer days— especially later in the day. Pay attention to slight changes in the color of the bean plants: a plant with adequate soil moisture appears dark green; when stressed, the green color shows hints of gray. Following emergence of the first true leaves, water stress will be very evident as a stressed plant tends to push the first true leaves together and upright. These stress symptoms typically show up on field edges where pre-irrigation coverage may not have been adequate, or where soil is more compacted.Monitor stress daily and wait as long as possible before the first irrigation to allow for deep rooting, promote early and uniform flowering, and inhibit weed competition. Apply about an inch of water with the first drip irrigation. Subsequent irrigations should be scheduled using evapotranspiration data from your local CIMIS station or another sources , and based on the percent canopy of the bean plants at time of irrigation.Fresh market beans are at their best when the seeds inside the pod are still very small and the bean is still tender. Bean pods form quickly; the harvest must be timed well to avoid harvesting any beans that are “over-mature.” On many fresh market “round pod” bean varieties, you shouldn’t be able to see bumps in the pod indicating seed development. Open random beans to check for over-maturation. Another good field test to determine market quality is to break the beans in half—they should break easily and not bend. Harvest in the morning when the temperature is cooler. Harvest efficiency is related to the picker’s ability to grab as many beans as possible in a single handful and pull them off the plant with enough care not to break any beans at the stem end. Efficient bean harvest is a fine art that takes a strong back, practice, and fast hands. A good bean picker is able to pick 50 lbs., or roughly two 5-gallon buckets per hour. This rate is only possible when the beans are heavily laden with evenly mature green beans. Sorting beans when harvesting is simply not economically viable. Depending on variety and uniformity of maturation, a stand of beans can be harvested one, two, or three times. The over-mature pods from extended harvest need to be sorted out, and this task is simply not economical. When the next succession is ready to go it is time to walk away from the last planting.Field bindweed is a perennial weed that can persist in many cultivated and unmanaged landscapes .