Before planting it is a good idea to find your USDA Zone info to estimate 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.

The first chance to plant marigold in London should be estimated by looking at the USDA zone info.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost.

It's a bad idea to plant marigold until after the last frost because they require warm weather.

The earliest that you can plant marigold 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 marigold and expect a good harvest is probably August. Any later than that and your marigold may not have a chance to fully mature. Starting your marigold indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in London. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for London and it can change quite a bit from year to year. Since half of the time in London there is a last frost after April 15 be ready to protect your marigold if you have 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.