One of the first steps you take when you are making a decision about 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.

By looking at the USDA zone info for Riverside it's a good idea to figure out when you can plant foxglove.

Planting Calendar for Foxglove

Frost tolerance for foxglove:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Foxglove do well in mild cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant foxglove in Riverside 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 foxglove and expect a good harvest is probably September. You probably don't want to wait any later than that or else your foxglove may not have a chance to really do well. Starting your foxglove indoors is a great way to get them started a couple of 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.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Riverside and it can change quite a bit from year to year. Since half of the time in Riverside you get surprised by a frost after April 15 be ready to cover your foxglove if you have a surprise late frost.

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.