by Lorinda Balfanz
There are a number of season extending techniques that can be incorporated into a planting schedule for vegetable production. These techniques can benefit gardeners by producing crops earlier in the spring and/or extending harvest later into the fall. One of these techniques is the use of transplants in the garden. With proper planning and favorable conditions, transplants can provide earlier harvests, lower costs, and healthier plants. A transplant is a seed grown in controlled conditions (such as a greenhouse) then transplanted to a field as a “plug”. Harvest time for transplanted crops can be 3 to 4 weeks ahead of direct seeded crops. Transplants are in the field for a shorter amount of time making succession planting or multiple cropping possible which can increase yields and profit.
Many crops are grown in production as transplants while others are still grown as direct seeds. Ultimately, it’s up to the individual grower to determine if transplants are the right fit for their farm system. Besides harvest timing and pre-planting plans, it is important to consider production costs of transplants versus direct seeds. Transplants have a higher initial cost because they involve starting plants from seeds in a greenhouse (instead of directly seeding in the field) and more time is spent planting the plugs in the field. However, there is a season long advantage for many transplanted crops including lower weeding costs, less irrigation and more uniform plant production. A general rule of thumb is transplant if seed cost is high, direct seed if seed cost is low.
Most of the seeds that are being successfully used as transplants are expensive or difficult to grow. A good example is celery seeds. Celery seeds are very small, germinate slowly and the seedlings grow slowly as well. Because the germination process for transplants takes place in a greenhouse, celery seedlings are more developed before planting in the field. This gives the celery an advantage over the emerging weeds. Transplants do not need to compete with the weed seeds for nutrients and water necessary to germinate since they’ve already passed that stage. Transplants can also shade out weed seeds and deter them from germinating. Other benefits of transplants include disease prevention and pest issues that occur with germinating seeds in the field. These weed, disease, and pest issues eat into your profitability. As with most cropping decisions, it is recommended to plant a small test plot before making a full switch to transplant production. One can then determine if the choice of plant is economically and physiologically suitable for transplanting for a particular grower’s needs and market conditions.
1. Bachmann, J. 2005. Season extension techniques for marketgardeners. ATTRA. National Sustainable Agriculture Information Service.
2. Anderson, B., and S. Wright. 2011. Season extension tools &techniques. University of Kentucky Cooperative Extension Service.
3. Katz, M. 2003. Transplanting vs. direct seeding. The Grower. Vol. 13. No. 10.
4. Schrader, W.L. 2000. Using Transplants in Vegetable Production. University of California, Division of Agriculture and Natural Resources. Publications 8013.