When to Plant Hemerocallis in Castle Rock, CO

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when to plant hemerocallis in Castle Rock by using the USDA zone info.


Planting Calendar for Hemerocallis

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

You can plant hemerocallis a little bit earlier in the year because they are moderately cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hemerocallis
Possibly ok, but a risky time to plant hemerocallis
Probably not a good time to plant hemerocallis

The earliest that you can plant hemerocallis in Castle Rock 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 hemerocallis and expect a good harvest is probably September. If you wait any later than that and your hemerocallis may not have a chance to fully mature. You can get started a little bit earlier by starting your hemerocallis indoors.

Last Frost Date

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

Since the USDA zone info for Castle Rock is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Castle Rock it frosts late in the year after April 15 so just be sure to be ready to protect your hemerocallis 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.