The USDA Zone info is a great tool for gardeners to help us estimate 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 Menlo Park can be reffered to in order to figure out when it's possible to plant delphinium.

Planting Calendar for Delphinium

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

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

The earliest that you can plant delphinium 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 delphinium and expect a good harvest is probably September. Any later than that and your delphinium may not have a chance to really do well. You can get started a couple of weeks earlier by starting your delphinium indoors.

Last Frost Date

The average date of last frost is February 15 in Menlo Park. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Menlo Park is an average the actual date of last frost changes from year to year. Half of the time in Menlo Park it frosts late in the year after February 15 so be sure to be ready to cover your delphinium in the event of a 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.