Begin by using fresh seeds.
If using leftover seeds from the previous year, test for germination first. Place a specific number of seeds, such as 10, 50 or 100 on a moistened paper towel. Fold the moistened paper over the seeds and put it in a plastic bag in a warm place. Take the paper towel out and inspect the seeds twice a day, spraying with water as needed to maintain moisture around the seeds. After the usual number of days required to germinate that variety, count to see how many have germinated and calculate the percentage of germination.
Before releasing biocontrols, check with your supplier to determine if long residual pesticides have been applied to incoming plant material that may adversely affect the biological control agents. For successful thrips management using biocontrol, begin introductions of natural enemies on young plants or in propagation areas before thrips are detected.
Beneficial nematodes are an easy way to begin a biocontrol program in greenhouses. Beneficial nematodes (Steinernema feltia) are best applied as a media drench to target the fungus gnat larvae. Treat as soon as possible (2 to 3 days) after sticking cuttings, planting plugs or starting seeds.
The following pest management resources have recently been updated.
2017-2018 New England Greenhouse Floriculture Guide
300+ pages of current recommendations for nonchemical and chemical management of greenhouse insects, mites, diseases, weeds and algae, plus recommendations for using plant growth regulators.
$40 includes postage and handling: To Order: www.negreenhouse.org
Some growers shut down their greenhouses for a few weeks during the winter expecting the cold temperatures to be sufficient to freeze and eradicate all of their pest populations. However, some pests can survive and continue on your spring crops, especially if infested debris is left in the greenhouse.