One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Riverside you can estimate when it's the best time to plant tropical hibiscus by reviewing the USDA zone info.

Planting Calendar for Tropical Hibiscus

Frost tolerance for tropical hibiscus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You should not plant tropical hibiscus until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant tropical hibiscus in Riverside is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant tropical hibiscus and expect a good harvest is probably August. If you wait any later than that and your tropical hibiscus may not have a chance to really do well. Starting your tropical hibiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Riverside. It might get as low as -10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Riverside and it will vary from year to year. Since half of the time in Riverside you get surprised by a frost after April 15 be ready to protect your tropical hibiscus if you have one of those late frosts.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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