Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant sweet sultan in Castle Rock should be estimated by checking out the USDA zone info.

Planting Calendar for Sweet Sultan

Frost tolerance for sweet sultan:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant sweet sultan a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant sweet sultan in Castle Rock is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sweet sultan and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet sultan may not have a chance to fully mature. Starting your sweet sultan 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 Castle Rock. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Castle Rock is not always accurate the actual date of last frost is different every year. Since half of the time in Castle Rock it frosts late in the year after April 15 be ready to cover your sweet sultan in the event of a late frost.

USDA Zone Info for Castle Rock

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 Castle Rock

You may be interested in your other planting guides for Castle Rock.