One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Siloam Springs can be reffered to in order to figure out when you can plant calendula.

Planting Calendar for Calendula

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

Since calendula are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant calendula in Siloam Springs 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 calendula and expect a good harvest is probably September. Any later than that and your calendula may not have a chance to really do well. Starting your calendula indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Siloam Springs the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Always keep in mind that USDA zone info for Siloam Springs is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Siloam Springs you get surprised by a frost after April 15 be ready to cover your calendula in the event of one of those late frosts.

USDA Zone Info for Siloam Springs

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Siloam Springs

You may be interested in your other planting guides for Siloam Springs.