Storage of vegetable plug transplants

If field planting is delayed by rain and plug transplants must be held, it is important to monitor them closely to maintain plant health and vigour. Plug transplants can be returned to the greenhouse or stored outside, in an area that receives direct sunlight and is sheltered from the wind. The racks should be elevated to prevent root growth through the bottom of the plugs. If there is a risk of frost, be sure to bring the transplants inside — in the greenhouse, a trailer, or barn. Plants should not generally be stored in an enclosed trailer or barn for more than 1 or 2 days, as this may result in very soft, elongated plants, especially in crops such as tomatoes.

The plants should be checked throughout the day, and watered regularly, never allowing the plugs to dry out. It is best to water the plants thoroughly in the morning, then spot water dry areas in mid-afternoon. Transplants should not be watered heavily late in the day, as this may promote disease.

If planting is delayed longer than 5 to 7 days and the transplants begin to show nutrient deficiency symptoms, they can be fertilized with a soluble fertilizer such as 20–8–20 or 20–10–20. This can be applied in water mixing according to the manufacturer's directions. The solution may be applied over the plants with the sprinkler wand or using a dip tank. Take care not to overfertilize.

Research has shown that, if properly stored, tomato transplants can be held for up to two weeks with little reduction in plant stand or vigour (see Table 1).