One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of estimating when it's a good idea to plant tree onions is to consult the USDA zone info for Harrison.

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 moderate cold which means that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant tree onions in Harrison 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. 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

In Harrison the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that USDA zone info for Harrison may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Harrison last frost occurs after April 15 so make sure that you are prepared to cover your tree onions in the event of one of those late frosts.

USDA Zone Info for Harrison

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Harrison

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