The First Frost Warning: Preparing the Garden for Colder Nights
The air is changing.
There’s a crispness in the mornings now — that unmistakable edge that tells you summer has truly slipped away. You step outside and the garden feels quieter, softer somehow. The zinnias still bloom, the basil still leans toward the sun, but everything seems to be holding its breath. The forecast confirms it: a light frost is on the way.
In Central Oregon, we know better than to take that lightly. What the weather app calls 34°F might mean 29°F in a low-lying field, or 27°F in the shade of the ridge. Cold air settles, and our high desert home has a way of surprising us with the first true kiss of frost.
So this isn’t a farewell to the growing season — not yet. But it is a gentle reminder: begin the gathering. Pick what’s tender. Prepare what you want to save. And step into the rhythm of the season as it slows.
What Is a Light Frost — and Why It Matters
A light frost typically happens when temperatures dip between 33–36°F for several hours, and you’ll often see a delicate layer of white on rooftops and grass in the early morning. But even if the air temperature stays above freezing, plants can experience damage when the ground or nearby surfaces radiate cold.
Basil, cucumbers, squash, and tomatoes — these are the ones that suffer first. You may wake up to curled leaves, blackened edges, or even collapsed vines. It’s not always a death sentence for the garden, but it’s often the beginning of the end for your tender summer crops.
And if you're in a frost pocket — a low spot, near water, or out in the open — your garden could freeze even if the rest of town doesn’t.
What to Harvest or Protect Right Now
Tender Herbs
Basil, dill, mint, and parsley won’t survive much cold. Harvest what you can and either dry it, chop it into ice cube trays with olive oil, or blitz it into a quick pesto to freeze. Even a brief dip into the 30s can turn basil leaves black overnight.
Tomatoes — Especially the Green Ones
Anything red should come off the vine immediately. Green tomatoes can be picked and ripened indoors — place them in a cardboard box or paper bag, ideally with a banana or apple to help things along. If you have too many, think about green tomato salsa or chutney!
Squash, Peppers & Cucumbers
These plants won’t like a frost. If you want to gamble, cover them with old sheets or frost cloths at night. But don’t wait too long to pick what’s usable. Even one cold night can leave fruits mushy or scarred.
Root Vegetables
Carrots, beets, and potatoes are more frost-tolerant — in fact, a light frost can make them sweeter. But if you’re in an area where the ground freezes early, you might want to dig a few now just in case.
Cut Flowers
Zinnias, cosmos, and sunflowers might hang on a bit longer, but we always like to gather a final bouquet before that first frosty morning. Their bright faces on the kitchen table are the best kind of goodbye.
Other Things to Do This Week
Bring in potted plants: Especially herbs or annuals that won’t survive frost.
Cover what you want to protect: Use row covers, frost blankets, or even old bedsheets overnight.
Start pulling spent plants: If something’s done producing, add it to your compost pile and clear the space.
Take a garden walk: Make notes, take photos, and begin dreaming for next year.
What Central Oregon Teaches Us About Change
One of the gifts of living here — in a place where the weather can turn on a dime — is that it teaches you to pay attention. You learn to read the land. To notice the way cold air slides into hollows. To sense when the breeze changes. To listen.
This isn’t the end. It’s the beginning of the shift. The garden is still alive, still offering, still beautiful — but it’s time to begin letting go of summer’s abundance.
And maybe that’s not just true of the garden.
Light Frost Checklist
(Tuck this into your pocket or screenshot for later)
✅ Harvest basil and other tender herbs
✅ Pick all ripening and green tomatoes
✅ Bring in any container plants
✅ Snip a “last chance” bouquet of flowers
✅ Cover squash, cucumbers, or peppers if you want to extend the season
✅ Pull spent plants and compost them
✅ Walk the garden and take it all in — it won’t look like this again until next year
The Next Frost Will Likely Be a Hard One
This week may just bring a light frost — a gentle warning. But if you’ve gardened here in Central Oregon for more than a season or two, you know what comes next: the real one. A hard frost, with temps dipping into the 20s, is likely not far behind.
And that one doesn’t play around.
It won’t just singe the tips of basil leaves or leave dew on the lawn. It will end the season in one cold breath. Tomato vines will collapse, zinnias will melt, and summer’s last holdouts will give way to the deeper quiet of fall.
So while this week may not be the end, it’s wise to treat it as your window — your chance to prepare, protect, and savor. Because once that hard frost arrives, the garden as we know it won’t look the same again until spring.