One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant delphinium in Robbins can be determined by checking out 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.

You can plant delphinium a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant delphinium in Robbins 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 fully mature. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Robbins. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Robbins and it is different every year. Since half of the time in Robbins you get surprised by a frost after April 15 be ready to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Robbins

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Robbins

You may be interested in your other planting guides for Robbins.