One of the best tools that you have as gardeners to help us estimate 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.

In Longmont you can determine when it's a good idea to plant argyranthemum by using the USDA zone info.

Planting Calendar for Argyranthemum

Frost tolerance for argyranthemum:	Not tolerant of frost.
When to plant:	After the last frost.

Since argyranthemum do not do well in cold weather it is important to wait until after the last frost before you can plant them.

The earliest that you can plant argyranthemum in Longmont is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant argyranthemum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your argyranthemum may not have a chance to really do well. Starting your argyranthemum 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.

Since the USDA zone info for Longmont may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Longmont you get a frost after April 15 so make sure that you are prepared to cover your argyranthemum in the event of 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.