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.

It's a good idea to determine when it's the best time to plant tree onions by reviewing the USDA zone info for Herriman.

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 are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Herriman 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. If you wait any later than that and your tree onions may not have a chance to really do well. Starting your tree onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Herriman. It might get as low as 0°F during the coldest months of winter.

Remember that USDA zone info for Herriman is just an average and the actual date of last frost will vary from year to year. Half of the time in Herriman there is a last frost after April 15 so make sure that you are prepared to protect your tree onions if you have a surprise late frost.

USDA Zone Info for Herriman

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 Herriman

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