When to Plant Impatiens in Cupertino, CA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's possible to plant impatiens is to consult the USDA zone info for Cupertino.


Planting Calendar for Impatiens

Frost tolerance for impatiens: Not tolerant of frost.
When to plant: After the last frost.

It's probably a bad idea to plant impatiens until after the last frost when the weather gets warmer because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant impatiens
Possibly ok, but a risky time to plant impatiens
Probably not a good time to plant impatiens

The earliest that you can plant impatiens in Cupertino 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 fully mature. You can get started a few weeks earlier by starting your impatiens indoors.

Last Frost Date

In Cupertino the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Cupertino is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Cupertino it frosts late in the year after February 15 be ready to protect your impatiens in the event of one of those late frosts.

USDA Zone Info for Cupertino

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 Low25°F
Highest Expected Low30°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 Cupertino

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