When to plant melon (cantaloupe/watermelon) in St. Louis

Melon (cantaloupe/watermelon) is frost-tender, so every date keys off St. Louis's last spring frost of Mar 30.
Step 1 · Sow
Start seeds indoors
Mar 20 – Apr 10
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
May 20 – Jun 10
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Aug 3 – Aug 28
Picking runs until conditions turn against the crop.
Window
Days to maturity
75 – 100 d
St. Louis's 218-day season leaves this much room.
Melon (cantaloupe/watermelon) on St. Louis'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
MAR 30
NOV 5

Common questions

When can I sow melon (cantaloupe/watermelon) outdoors in St. Louis?

Direct-sow around mid May (May 20–Jun 10) in St. Louis, based on its local frost dates. Confidence 81%.

When will melon (cantaloupe/watermelon) be ready to harvest in St. Louis?

Expect to harvest from around early August (Aug 3–Aug 28) in St. Louis, based on its local frost dates. Confidence 76%.

When should I start melon (cantaloupe/watermelon) seeds indoors in St. Louis?

Start seeds indoors around mid March (Mar 20–Apr 10) in St. Louis, based on its local frost dates. Confidence 80%.

When can I transplant melon (cantaloupe/watermelon) outdoors in St. Louis?

Transplant outdoors around mid May (May 20–Jun 10) in St. Louis, based on its local frost dates. Confidence 81%.

How long is the growing season in St. Louis?

St. Louis has roughly 218 frost-free days, which is enough time to grow melon (cantaloupe/watermelon) to maturity outdoors.

The rule of thumb

Sow melon (cantaloupe/watermelon) 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 St. Louis's frost dates.

Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.