One of the first steps you take when you are making a decision about 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 reviewing the USDA zone info for Glasgow it's possible to figure out when it's the best time to plant watercress.

Planting Calendar for Watercress

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

Watercress do ok in some cold which means that you can plant them slightly earlier in the year than other frost tender plants.

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

Last Frost Date

The average date of last frost is April 15 in Glasgow. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Glasgow 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 Glasgow it frosts late in the year after April 15 be ready to protect your watercress if you have a surprise late frost.

USDA Zone Info for Glasgow

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 Glasgow

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