One of the first steps you take when you are making a decision about 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.

By reviewing the USDA zone info for Menlo Park it's possible to determine when it's the best time 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.

Welsh onion tend to make it in some cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant welsh onion in Menlo Park is February. However, you really should wait until March 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 September. 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 little bit earlier.

Last Frost Date

On average the last frost is on February 15 in Menlo Park. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Menlo Park is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Menlo Park you get a frost after February 15 be ready to protect your welsh onion if you have a surprise late frost.

USDA Zone Info for Menlo Park

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Menlo Park

You may be interested in your other planting guides for Menlo Park.