Editor’s note: Get Growing, written by the La Plata County Extension Office’s Master Gardener Program, appears during the growing season. It features timely tips and suggestions for your garden and landscape.
The seed catalogs have all arrived. Hopefully, your orders are in and arriving. Once those seeds are in hand, how will you get them started?
I am a proponent of starting indoors early, using a heated table with grow lights that jump start germination. Soil temperature is a critical factor for germination. Some seeds can germinate in soil with a temperature as low as 40 degrees. Lettuce and cabbage, and the brassicas (kale, broccoli, cabbage, etc.), can germinate in cold soil. Others such as some melons, squash, and okra may germinate in soils as warm as 100 degrees. But these very cold and very warm soils are not within the optimal germination range, and they will greatly increase the number of days to emergence of a seedling. It’s certainly possible to create different soil environments for different seedlings, and if you are a production grower you might do that, but for a home or small lot grower there is a temperature that suits the majority of vegetable seeds for successful germination and emergence. That temperature is 75 degrees F, which is the upper limit for a few plants, and the lower limit for some others, but right in the middle for many popular vegetables. If you can get your soil to 75 degrees you should have reliable germination for most vegetables.
The exceptions are squash, and okra which really prefer a range of 85 degrees to 95 degrees. Of course temperature is not the only factor. Your seedlings need consistently moist but not wet soil, a growing media pH range between 6 and 7, a gentle fertilizer (once they start developing leaves), and a light source that is not too far from your seedlings, or too weak that it will cause plants to get leggy and have a weak structure. 12 to14 hours a day of direct gentle is ideal.
If you have questions, the Extension Office and your La Plata Master Gardeners can provide assistance.
Clint Kearns is a Colorado Master Gardener and a La Plata County resident.
