One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant tree onions in West Covina 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 moderate cold which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant tree onions in West Covina is February. However, you really should wait until March 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 September. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

The average date of last frost is January 31 in West Covina. In the coldest months of winter you can expect an average low temperature of 30°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for West Covina and it is different every year. Half of the time in West Covina last frost occurs after January 31 so always be ready to cover your tree onions if you have a surprise late frost.

USDA Zone Info for West Covina

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in West Covina

You may be interested in your other planting guides for West Covina.