Seed priming has changed how I plant many of my garden seeds. Seeds are precious and expensive so taking steps to improve germination makes sense. It also gets our garden plants growing faster. Be sure to read a previous blog post on seed priming which gives techniques for 12 different vegetables.

Seed Priming Tips for Vegetable Gardeners

The same website, GrowVeg.com, provided instructions for seed priming of spinach seeds. They’re finicky for me when I direct sow them. Though spinach seeds will germinate at soil temperatures as low as 35 degrees F, the optimal temperature range for germination is 65-75 degrees F. During the winter months here in USDA Zone 10b, the soil temperature typically does not reach those temperatures.

Spinach seeds do germinate when I direct sow, but germination percentage is suboptimal and slow. Sometimes I grow starts in a sunny kitchen window. So here are the instructions from Growing Spinach in Spring for seed priming spinach seeds.

To improve my germination luck, I prime spinach seeds a few days before planting them. This process involves soaking the seeds in room temperature water overnight, then letting them dry at room temperature for a day or two. When spinach seeds are primed in this way, the first stage of germination takes place under warm, clean conditions, so the seeds are much faster to sprout after they are planted in the garden.

I followed the same instructions for radish seeds, since their optimal germination temperature range is 65-85 degrees F. I planted the spinach and the radish seeds on April 12 and six days later they had germinated and poked through the soil. Today, before the sun warmed the soil the temperature was 60 degrees F. at 1-3 inches—still below the optimal range.

Conclusions:
1. Seed priming spinach seeds hastened germination from a typical 6-14 days at optimal soil temperatures to 6 days at suboptimal temperatures.
2. Seed priming radish seeds may not have speeded germination significantly since typical days to germination at optimal temperatures are 4-10 days. I probably won’t prime them again but just plant a few more than I usually do.

Looking forward to this.