The USDA Zone info is a great tool for gardeners to help us determine 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.

By looking at the USDA zone info for Roseburg you will 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 the last frost has passed.

Ageratum are not cold tolerant which tells us that it is necessary 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 Roseburg 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 ageratum and expect a good harvest is probably September. Any later than that and your ageratum may not have a chance to grow to maturity. 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 the last frost has passed is on February 15 in Roseburg. You should expect an average low temperature of 20°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Roseburg and it is different every year. Half of the time in Roseburg last frost occurs after February 15 so make sure that you are ready to protect your ageratum in the event of a surprise late frost.

USDA Zone Info for Roseburg

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Roseburg

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