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 Gladstone you can figure out when it's the best time to plant tree onions by looking at 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 do ok in very little cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Gladstone 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. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Gladstone. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Gladstone is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Gladstone it frosts late in the year after April 15 so be sure to be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Gladstone

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Gladstone

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