When to plant summer squash / zucchini in Knoxville
Summer squash / Zucchini is frost-tender, so every date keys off Knoxville's last spring frost of Apr 8.
Step 1 · Sow
Start seeds indoors
Apr 5 – Apr 26
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
May 10 – May 31
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 24 – Jul 9
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Knoxville's 201-day season leaves this much room.
Summer squash / Zucchini on Knoxville's growing year
Frost-bounded season with crops mapped onto the 12-month axis.
Frost risk Growing Harvest
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
FROST
FROST
APR 8
OCT 28
Common questions
When can I sow summer squash / zucchini outdoors in Knoxville?
Direct-sow around early May (May 10–May 31) in Knoxville, based on its local frost dates. Confidence 86%.
When will summer squash / zucchini be ready to harvest in Knoxville?
Expect to harvest from around late June (Jun 24–Jul 9) in Knoxville, based on its local frost dates. Confidence 80%.
When should I start summer squash / zucchini seeds indoors in Knoxville?
Start seeds indoors around early April (Apr 5–Apr 26) in Knoxville, based on its local frost dates. Confidence 85%.
When can I transplant summer squash / zucchini outdoors in Knoxville?
Transplant outdoors around early May (May 10–May 31) in Knoxville, based on its local frost dates. Confidence 86%.
How long is the growing season in Knoxville?
Knoxville has roughly 201 frost-free days, which is enough time to grow summer squash / zucchini to maturity outdoors.
The rule of thumb
Sow summer squash / zucchini 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. Every date on this page is derived from that rule and Knoxville's frost dates.
Confidence 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.