Most perennial seeds need cold stratification to germinate well. But what does that actually mean? Simply put, the seeds you harvest this year need to be kept cold and moist—around 40°F—for about 4–12 weeks, depending on the species, before they’ll sprout.
That’s why we recommend sowing your seeds in early winter. Below, we’ll walk you through why seeds need cold stratification, how to do it, and what plants we recommend to start.
1. Why do seeds need “cold stratification”?
Survival strategy
In nature, seeds drop in the fall. If they sprouted right away, the winter cold would kill the seedlings.
So the seeds evolved a dormancy mechanism that requires weeks or months of cold, moist conditions before they’ll wake up.Signals that winter has passed
Cold stratification mimics winter. The seed only germinates after it senses:consistent cold temperatures (typically 32–45°F / 0–7°C)
moisture
These cues tell the seed: “Okay, winter is over—safe to grow.”
Breaks physiological dormancy
Some seeds contain hormones (like abscisic acid) that suppress germination. Cold exposure reduces these hormones and activates growth hormones instead.
2. How to winter sow it?
There are dozens of ways to do it: generously sprinkle it in your yard, plant it in a 1-gallon plastic milk jar, use clear tuppleware, containers, or nursery pots… and leave them outside. (We won’t call it winter sowing if you start them indoor… ) We recommend utilizing what you have – you don’t need a fancy setup. We had lots of nursery pots so that’s how we did it.
Steps:
- Fill your container with well-drained soil
Make sure there are drainage holes under your container—milk jugs, nursery pots, takeout containers, etc. Don’t need to start native plant seeds in compost since they naturally grow in rocky, sandy or low-organic soil. - Sow and label your seeds with a waterproof marker
Sprinkle them on top of the soil. Lightly cover them – don’t cover too much as many native seeds prefer light coverage. - Water gently, leave them in a sunny spot and wait…
Moisten the soil thoroughly and let nature take care of the rest…. - Sprout in spring
When soil temperatures become warm in spring (usually March–April in Utah valleys; later in higher elevations), seedlings will begin to emerge. It depends on the type of perennials. patience is required since it might take a while.
3. What are easy to start and where can I get them?
You can try any seeds but here are some common ones we recommend-
- Indian blanket flowers
- Rocky Mountain Pentsemon
- Showy Milkweed (for Monarch butterflies!)
- Mexican hat /Upright prairie coneflower
- Rocky Mountain Bee plants
You can purchase native plant seeds online (High Country Garden, True Leaf Market, etc) but if you’re on a budget, here are some good resources:
- Utah Native Plant Society (UNPS) often hosts seed-sharing events.
Local FB gardening groups, FB marketplace, and local libraries,
Gardening sharing platform: cultivate
