One of the first steps you take when you are getting a good idea 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.

By referring to the USDA zone info for London it's a good idea to determine when you can plant astilbe.

Planting Calendar for Astilbe

Frost tolerance for astilbe:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Astilbe do ok in some cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

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

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in London. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for London is an average the actual date of last frost can change quite a bit from year to year. Half of the time in London you get surprised by a frost after April 15 so make sure that you are prepared to protect your astilbe in the event of a late frost.

USDA Zone Info for London

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 London

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