One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A way of figuring out when you can plant sunflowers is to look at the USDA zone info for Manteca.

Planting Calendar for Sunflowers

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

Since sunflowers do not do well in cold weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sunflowers in Manteca 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 sunflowers and expect a good harvest is probably September. Any later than that and your sunflowers may not have a chance to grow to maturity. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Manteca. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Manteca may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Manteca you get a frost after February 15 so make sure that you are prepared to cover your sunflowers if you have a late frost.

USDA Zone Info for Manteca

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 Manteca

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