One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's possible to plant impatiens by referring to the USDA zone info for Redwood City.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since impatiens do not do well in cold weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant impatiens in Redwood City 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 impatiens and expect a good harvest is probably September. Any later than that and your impatiens may not have a chance to really do well. Starting your impatiens indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Redwood City is just an average the actual date of last frost changes from year to year. Since half of the time in Redwood City it frosts late in the year after February 15 be ready to cover your impatiens if you have one of those late frosts.

USDA Zone Info for Redwood City

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 Redwood City

You may be interested in your other planting guides for Redwood City.