Jun 14, 2017

How to seed, transplant vegetables

Stand establishment is one of the most critical steps in producing a successful crop of vegetables.

Stand establishment means getting the crop off to a quick, healthy, and uniform start in the field. It also means using a planting arrangement that provides adequate room for plants to grow and develop, and one that makes it easy to manage the crop throughout the season. Weed control, pest control, fertilizer applications, irrigation, timing of harvest, and yield will all be influenced by the initial stand establishment.

Seeding and transplanting. Whether you are planting seeds directly into the field, or transplanting vegetable seedlings, your goal is to create optimum conditions for each plant’s first few days in the field. The goal is for seeds to start germinating rapidly, and for seedlings to suffer as little transplant shock as possible, as they move from seedling trays to the field.

Seeds. Seeds should have solid contact with moist soil so that they start the germination process soon after planting. Adjust seed depth to insure that seeds are placed in a zone with moisture, and that they are neither too shallow nor too deep for emerging from the soil. If field soil is light and fluffy, gently pack down the soil over the planted seed so that the seeds are in direct contact with the soil. Make sure that soil temperatures are in the optimum range for the crop. Some vegetable seeds, such as beans and corn, germinate very slowly in cold soils; slow germination and emergence gives soil-borne pests more opportunity to damage the crop. Seeding equipment should be adjusted to ensure even placement of seeds along the row, at the optimum spacing for the crop. Too many skips in the row will result in lower yield; if too many seeds are planted, they will need to be thinned so that the plants aren’t overcrowded.

Transplants. Transplants planted into the field will experience some level of transplant shock. The goal is to minimize this transplant shock and get plants growing as soon as possible. Key to minimizing transplant shock is starting with transplants that are well watered, and supplying more water immediately after transplanting. Avoid transplanting into dry soil.

Even when planting into moist soils, newly planted seedlings need additional water. This can be accomplished by adding water to the transplant hole as the plants are set in, or by irrigating immediately after transplanting a field. When placing seedlings down in the planting hole in the field, ensure that the top of the root ball is completely covered with field soil. If the root ball is exposed, it will dry out very quickly and the seedling will not thrive. At this stage, overhead irrigation is more effective than drip irrigation, because the plant roots will be too far away from the drip lines. A gentle rainfall is also welcome after transplanting a field.

Tubers, crowns, cloves and sets. Some vegetable crops are grown not from seeds or transplants, but from another plant part.  We plant pieces of potato tubers, cloves of garlic, root crowns of asparagus and rhubarb, and sometimes small onions, called sets, to establish these crops in the field. Specific recommendations can be found on how and when to plant these crops, but in general, they can be treated like seeds or transplants.

Choosing equipment

Small farm on a budget. Most small farms start out using a push “plate” seeder for direct-seeded crops. A seeder can save a lot of time and seed compared to hand-seeding. Push plate seeders are relatively inexpensive and easy to purchase. Push seeders typically have interchangeable notched plates that rotate inside the seeder, picking up individual seeds and dropping them through a hole in the side of the seed hopper. Seeders vary in their degree of precision and the number of different seed plates that can be used; prices vary accordingly.

Desirable features of a single-row push seeder include: easy to push in a straight line, precise and even seed placement, allows accurate depth adjustment, easy to fill and empty, easy to see the seeds drop.

Hand-transplanting can be fast and efficient for the small, diverse farm. Simple hand tools can be used to make hand-transplanting more efficient and easier. One popular hand tool for transplanting is the Japanese transplanting hoe (hori hori). One Pennsylvania company offers a transplanting tool that is used while standing.

Medium to large farm. Four acres seems to be the breaking point where most farms go to tractor-mounted seeders and transplanters. Tractor-mounted seeders control seed spacing with a plate, a punched belt, seed cups, or vacuum systems. Tractor-mounted seeds can save time when seeding over a large area. However, they can take longer to set up for planting.

Tractor-mounted mechanical transplanters are the next step up from transplanting by hand. Mechanical transplanters are not necessarily faster than hand transplanting, at least for small areas. However workers can ride the transplanter, feeding plants into the tubes, for many more hours than they can transplanting by hand. Water-wheel transplanters are very common because of their ability to deliver water and fertilizer directly into the transplanting holes, reducing transplant shock.

Best practices for planting

Seedbed preparation. Before planting seeds, it is important to prepare a good seedbed in the field. This will make planting easier and provide a better environment for seeds to germinate and emerge, especially for small-seeded crops such as carrots or lettuce. A proper seedbed is level and even, with no clods of soil or excess plant residue on the surface. Soil should be light and fluffy, with good tilth.

Straight rows. Planting straight rows is much more than a matter of farmer pride. Whether rows are planted by hand, by push seeder, or a tractor-mounted planter, it is essential to make those rows straight. Straight rows are much easier and faster to weed than crooked rows. It is difficult if not impossible to use cultivation equipment to weed a field of crooked rows, and even hoeing is much faster when rows are even and straight.

Row markers. Rows should be evenly spaced as well as straight. There are a number of ways to mark rows and keep them evenly spaced. Most push seeders will have an adjustable row marker. For transplants on a small scale, a row- marking rake or a push seeder without seeds can be used to mark rows. Some growers use home-made rolling dibblers, either pushed by hand or mounted on a tractor.

Spacing for good weed management

Set up your plant spacing for seeding and transplanting in a way that will make it easier to manage weeds later. Match up the spacing of the weeding tools you will be using (for example, 8-inch wheel hoe, 5-inch hula hoe, or mechanical cultivators) with row spacing. Choose a few plant spacings that work well with your equipment and don’t vary them. This will save time adjusting equipment or finding the right sized hoe.

Check the seeder. No matter which seeder you use, it is worth the time to check and make sure it is functioning properly. Seed tubes can clog up, plates can stop picking up seeds, or the spacing can be wrong. Lift the seeder and turn the drive wheel a few times to make sure seed is dropping down freely. It is also a good idea to go back over a row that has been planted, dig up a few seeds, and check to make sure they are being placed at the proper depth and spacing.

–Lee Stivers, Penn State University

References:

http://extension.psu.edu/business/start-farming/vegetables/factsheets/selecting-the-right-seeding-and-transplanting-strategies

http://extension.psu.edu/publications/agrs-028/view