One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In London you can figure out when it's a good idea to plant watermelon by referring to the USDA zone info.

Planting Calendar for Watermelon

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

Since watermelon are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant watermelon in London 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. Any later than that and your watermelon may not have a chance to grow to maturity. 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

On average all chance of frost has passed is on April 15 in London. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for London and it is different every year. Half of the time in London last frost occurs after April 15 so always be ready to protect your watermelon in the event of a late frost.

USDA Zone Info for London

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in London

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