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.

You should be able to determine when it's possible to plant dipladenia by using the USDA zone info for San Ramon.

Planting Calendar for Dipladenia

Frost tolerance for dipladenia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Dipladenia require warm weather which tells us that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant dipladenia in San Ramon 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 dipladenia and expect a good harvest is probably September. If you wait any later than that and your dipladenia may not have a chance to fully mature. If you are starting your dipladenia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for San Ramon is just an average the actual date of last frost changes from year to year. Half of the time in San Ramon it frosts late in the year after February 15 so always be ready to protect your dipladenia in the event of a surprise late frost.

USDA Zone Info for San Ramon

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 San Ramon

You may be interested in your other planting guides for San Ramon.