When to Plant Tree onions in Alpine, UT

One of the first steps you take when you are getting a good idea 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.

You can determine when it's the best time to plant tree onions in Alpine by referring to 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 are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant tree onions
Possibly ok, but a risky time to plant tree onions
Probably not a good time to plant tree onions

The earliest that you can plant tree onions in Alpine 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 grow to maturity. Starting your tree onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Alpine. It might get as low as -5°F during the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Alpine and it changes from year to year. Since half of the time in Alpine last frost occurs after April 15 be ready to cover your tree onions in the event of a late frost.

USDA Zone Info for Alpine

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°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 0°F.

Plants to Grow in Alpine

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