When to Plant Watermelon in Louisville, CO

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's possible to plant watermelon is to examine the USDA zone info for Louisville.


Planting Calendar for Watermelon

Frost tolerance for watermelon: Not tolerant of frost.
When to plant: After the last frost has passed.

Watermelon are not cold tolerant which tells us that you have to wait until it warms up after the last frost before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant watermelon
Possibly ok, but a risky time to plant watermelon
Probably not a good time to plant watermelon

The earliest that you can plant watermelon in Louisville is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant watermelon and expect a good harvest is probably August. You probably don't want to wait any later than that or else your watermelon may not have a chance to fully mature. If you are starting your watermelon indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Louisville the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Louisville is just an average and the actual date of last frost changes from year to year. Since half of the time in Louisville it frosts late in the year after April 15 be ready to cover your watermelon if you have a late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Louisville

You may be interested in your other planting guides for Louisville.