Before planting it is a good idea to find your USDA Zone info to figure out 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.

By reviewing the USDA zone info for Rockville Centre it's a good idea to estimate when you can plant tree onions.

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 barely cold tolerant which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant tree onions in Rockville Centre 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 few weeks earlier.

Last Frost Date

In Rockville Centre the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rockville Centre and it can change quite a bit from year to year. Half of the time in Rockville Centre it frosts late in the year after April 15 so be sure to be ready to protect your tree onions in the event of a surprise late frost.

USDA Zone Info for Rockville Centre

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Rockville Centre

You may be interested in your other planting guides for Rockville Centre.