One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 estimate when it's the best time to plant sweet williams in Longmont by checking out the USDA zone info.

Planting Calendar for Sweet Williams

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

Sweet Williams are moderately cold tolerant which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant sweet williams 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 sweet williams and expect a good harvest is probably September. You probably don't want to wait any later than that or else your sweet williams may not have a chance to really do well. Starting your sweet williams indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Longmont. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Longmont is an average and the actual date of last frost changes from year to year. Since half of the time in Longmont last frost occurs after April 15 be ready to protect your sweet williams 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.