Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Lowell you can estimate when it's a good idea to plant zinnia by referring to the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since zinnia require warm weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant zinnia 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 zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to grow to maturity. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Lowell. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Lowell is just an average and the actual date of last frost changes from year to year. Since half of the time in Lowell you get a frost after April 15 be ready to cover your zinnia in the event of a late frost.

USDA Zone Info for Lowell

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Lowell

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