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

The first opportunity to plant tree onions in Lowell should be figured out by reviewing the USDA zone info.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since tree onions do ok in moderate cold 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 tree onions in Lowell 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 tree onions and expect a good harvest is probably August. Any later than that and your tree onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your tree onions indoors.

Last Frost Date

On average the last frost is on April 15 in Lowell. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Lowell may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Lowell you get surprised by a frost after April 15 be ready to cover your tree onions if you have a surprise late frost.

USDA Zone Info for Lowell

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 Lowell

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