Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when to plant arabis is to look at the USDA zone info for Longmont.

Planting Calendar for Arabis

Frost tolerance for arabis:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant arabis much earlier in the year because they do well in cold.

The earliest that you can plant arabis in Longmont 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 arabis and expect a good harvest is probably September. If you wait any later than that and your arabis may not have a chance to fully mature. You can get started a few weeks earlier by starting your arabis indoors.

Last Frost Date

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

Since the USDA zone info for Longmont is not always accurate the actual date of last frost is different every year. Half of the time in Longmont it frosts late in the year after April 15 so be sure to be ready to cover your arabis if you have a surprise late frost.

USDA Zone Info for Longmont

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Longmont

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