One of the first steps you take when you are estimating your gardening schedule is find your 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 USDA zone info for Oelwein can be read to estimate when it's a good idea to plant alyssum.

Planting Calendar for Alyssum

Frost tolerance for alyssum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since alyssum are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant alyssum in Oelwein 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 alyssum and expect a good harvest is probably September. If you wait any later than that and your alyssum may not have a chance to grow to maturity. Starting your alyssum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Oelwein. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Oelwein is just an average the actual date of last frost changes from year to year. Half of the time in Oelwein it frosts late in the year after April 15 so just be sure to be ready to protect your alyssum if you have a late frost.

USDA Zone Info for Oelwein

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Oelwein

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