The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Mountlake Terrace should be used to determine when it's a good idea to plant welsh onion.

Planting Calendar for Welsh onion

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

You can plant welsh onion slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant welsh onion in Mountlake Terrace 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 welsh onion and expect a good harvest is probably August. Any later than that and your welsh onion may not have a chance to really do well. If you are starting your welsh onion indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Mountlake Terrace. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Mountlake Terrace may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Mountlake Terrace there is a last frost after March 15 so make sure that you are ready to cover your welsh onion if you have one of those late frosts.

USDA Zone Info for Mountlake Terrace

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Mountlake Terrace

You may be interested in your other planting guides for Mountlake Terrace.