Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant lupine in Riverside should be estimated by referring to the USDA zone info.

Planting Calendar for Lupine

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

You can plant lupine a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant lupine 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 lupine and expect a good harvest is probably September. Any later than that and your lupine may not have a chance to grow to maturity. If you are starting your lupine indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Riverside. You can expect an average low temperature of -10°F in 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 will vary from year to year. Half of the time in Riverside you get a frost after April 15 so make sure that you are ready to cover your lupine in the event of 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.