The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

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.

You can plant tree onions just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant tree onions in Newcastle 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 grow to maturity. If you are starting your tree onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Newcastle. You can expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Newcastle is just an average and the actual date of last frost will vary from year to year. Half of the time in Newcastle it frosts late in the year after April 15 so make sure that you are prepared to protect your tree onions if you have one of those late frosts.

USDA Zone Info for Newcastle

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 Newcastle

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