One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Markham can be used to determine when you can plant watermelon.

Planting Calendar for Watermelon

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

Since watermelon are not cold tolerant it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant watermelon in Markham 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 grow to maturity. You can get started a couple of weeks earlier by starting your watermelon indoors.

Last Frost Date

The average date of last frost is April 15 in Markham. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Markham is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Markham you get surprised by a frost after April 15 so just be sure to be ready to protect your watermelon if you have a late frost.

USDA Zone Info for Markham

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 Markham

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