One of the best tools that you have as gardeners to help us figure out 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.

By checking out the USDA zone info for Delta you should be able to figure out when it's a good idea to plant ageratum.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Ageratum are not cold tolerant which means that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Delta is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your ageratum may not have a chance to really do well. If you are starting your ageratum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Delta. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that USDA zone info for Delta may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Delta you get a frost after April 15 so just be sure to be ready to protect your ageratum if you have one of those late frosts.

USDA Zone Info for Delta

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Delta

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