One of the first steps you take when you are making a decision about 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.

The first chance to plant delphinium in Lone Tree can be estimated by referring to the USDA zone info.

Planting Calendar for Delphinium

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

Since delphinium do ok in moderate cold you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Lone Tree 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 delphinium and expect a good harvest is probably August. Any later than that and your delphinium may not have a chance to really do well. If you are starting your delphinium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Lone Tree. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Lone Tree is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Lone Tree it frosts late in the year after April 15 so make sure that you are ready to protect your delphinium if you have one of those late frosts.

USDA Zone Info for Lone Tree

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 Lone Tree

You may be interested in your other planting guides for Lone Tree.