One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Longmont you can determine when you can plant chrysanthemum by reviewing the USDA zone info.

Planting Calendar for Chrysanthemum

Frost tolerance for chrysanthemum:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since chrysanthemum do not do well in cold weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant chrysanthemum 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 chrysanthemum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your chrysanthemum may not have a chance to grow to maturity. Starting your chrysanthemum indoors is a great way to get them started a few weeks 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.

Just be sure to 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 Longmont and it changes from year to year. Half of the time in Longmont there is a last frost after April 15 so be sure to be ready to protect your chrysanthemum in the event of 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.