Why the Back of the Seed Packet is Lying to You in the PNW
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If you live in the Pacific Northwest, looking at the back of a seed packet is an exercise in creative fiction. Almost every packet of seeds sold in the United States comes with the exact same instructions: “Plant outdoors after all danger of frost has passed.”
Here is the brutal truth for PNW gardeners: our last frost date usually hits in April, but if you put a bean or squash seed into the ground in April, it will not grow. It will rot.
The Soil Temperature Trap
Seed packets are written for the Midwest and the East Coast, where the arrival of spring means the sun comes out and the ground heats up rapidly. Out here, our springs are just a slightly brighter shade of gray. The air might be 55 degrees, but our soil is still a cold, wet sponge.
Seeds don’t care about the calendar. They care about soil temperature. Most warm-weather crops (tomatoes, peppers, beans, squash) need soil that is consistently above 60-65 degrees to germinate. In Seattle or Portland, the soil often doesn’t hit that temperature until June.
What You Should Actually Do
1. Ignore the “Direct Sow” advice: Unless it’s peas, radishes, or kale, start your seeds indoors under a cheap LED shop light. You need to give them a 6-to-8 week head start while the mud outside dries out.
2. Use Cloches and Plastic: If you absolutely must plant outside early, warm your soil up artificially. Lay black plastic over your garden beds for two weeks before you plant, or put clear plastic cloches over your seedlings to trap the weak spring sun.
The next time you read a seed packet that tells you to plant your tomatoes in April, just laugh. Start them inside, and wait for June.