Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
Many growers choose not to produce their own transplants but contract with greenhouse growers locally or in the South. The majority of these transplants are of high quality and perform well in the field. However, each year, there are some shipments that have problems. The most common problem is transplants shipped before they are ready – without adequate root systems. These transplants will not perform well in the field, especially in earlier plantings. If possible, they should be placed in a greenhouse to finish growing before use.
Another issue is diseases. Bacterial diseases (such as bacterial spot), fungal blights (such as Alternaria or Gummy Stem), and viruses (such as Tomato Spotted Wilt Virus and INSV) have all been found in transplants at times. If a disease is suspected, have it quickly diagnosed. Do not plant diseased plants in the field. Southern grown transplants are most often the source so make sure that you are dealing with a grower with a good reputation for producing disease free plants.
Plants that are shipped without trays (already pulled) or that are bare rooted that are packed tightly in boxes must be planted quickly. Delays will lead to plant deterioration, leaf loss, and potential disease buildup.