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 USDA zone info for Lowell can be looked at to figure out when it's the best time to plant sunflowers.

Planting Calendar for Sunflowers

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

Since sunflowers are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in Lowell 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 sunflowers and expect a good harvest is probably August. If you wait any later than that and your sunflowers may not have a chance to grow to maturity. If you are starting your sunflowers indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Lowell. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Lowell is an average the actual date of last frost is different every year. Since half of the time in Lowell you get surprised by a frost after April 15 be ready to protect your sunflowers if you have a late frost.

USDA Zone Info for Lowell

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Lowell

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