The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant jerusalem artichokes in Longmont should be determined by referring to the USDA zone info.

Planting Calendar for Jerusalem artichokes

Frost tolerance for jerusalem artichokes:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since jerusalem artichokes do well in moderate cold you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant jerusalem artichokes 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 jerusalem artichokes and expect a good harvest is probably September. Any later than that and your jerusalem artichokes may not have a chance to grow to maturity. Starting your jerusalem artichokes indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Longmont. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Longmont is just an average the actual date of last frost will vary from year to year. Half of the time in Longmont last frost occurs after April 15 so always be ready to cover your jerusalem artichokes if you have one of those late frosts.

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.