Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant watermelon in Ottawa can be determined by referring to the USDA zone info.

Planting Calendar for Watermelon

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

Since watermelon require warm weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant watermelon in Ottawa 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. If you wait any later than that and 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 little bit earlier.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Ottawa is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Ottawa you get a frost after April 15 be ready to protect your watermelon if you have a late frost.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ottawa

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