Before planting it is a good idea to find your USDA Zone info to estimate 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 best time to plant tree onions in Thomson should be figured out by using 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.

Tree onions are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant tree onions in Thomson 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. You probably don't want to wait any later than that or else your tree onions may not have a chance to fully mature. Starting your tree onions 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 March 15 in Thomson. You can expect an average low temperature of 10°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Thomson and it can change quite a bit from year to year. Since half of the time in Thomson there is a last frost after March 15 be ready to protect your tree onions in the event of one of those late frosts.

USDA Zone Info for Thomson

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Thomson

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