Rockville 5 N, OR Frost Dates & Growing Season

The two dates every Rockville 5 N garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
May 29
~50% chance of frost after
First fall frost
Sep 14
~50% chance of frost before
Growing season
108 days
frost-free stretch
USDA zone
≈ 5b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost May 9 May 29 Jun 23
First fall frost Oct 1 Sep 14 Sep 1
Hard freeze (28°F), median last May 10 · first Sep 27

Computed from NOAA 1991–2020 climate normals at the ROCKVILLE 5 N station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Rockville 5 N

Computed from Rockville 5 N's own frost dates. Click any crop for the full zone-5 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Apr 3 – Apr 17 Jun 5 – Jun 12
🫑 Peppers Mar 20 – Apr 3 Jun 12 – Jun 19
🥬 Lettuce Apr 17 – May 1 May 1 – May 15 May 1 – May 29
🫛 Peas Apr 17 – May 1
🥕 Carrots May 8 – May 29
🥦 Broccoli Apr 10 – Apr 24 May 8 – May 22
🥬 Kale Apr 17 – May 1 May 1 – May 15 May 1 – May 15
🥒 Cucumbers May 1 – May 8 Jun 5 – Jun 12 Jun 5 – Jun 12
🥒 Zucchini May 1 – May 8 Jun 5 – Jun 12 Jun 5 – Jun 12
🫘 Green Beans (Bush) Jun 5 – Jun 12
🌽 Sweet Corn Jun 5 – Jun 12
🌿 Basil Apr 17 – May 1 Jun 5 – Jun 12 Jun 12 – Jun 19
🧄 Garlic Fall: Aug 3 – Aug 31

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Rockville 5 N's dates automatically after a lookup.

Reading the season in Rockville 5 N

At about 108 frost-free days, Rockville 5 N rewards efficiency: start warm-season crops indoors, favor short-season varieties, and lean on cold-tolerant crops — peas, kale, roots — that shrug off the shoulder-season frosts on either end.

Frequently asked questions

When is the last frost in Rockville 5 N, OR?

The average last spring frost in Rockville 5 N is around May 29, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Rockville 5 N, OR?

The average first fall frost in Rockville 5 N arrives around Sep 14. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Rockville 5 N?

About 108 frost-free days on average, from May 29 to Sep 14. That favors short-season varieties and transplants for warm-season crops, with cool-season vegetables doing the heavy lifting in spring and fall.

What USDA zone is Rockville 5 N in?

USDA zone 5b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.