Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when it's the best time to plant sweet woodruff by using the USDA zone info for Waterloo.

Planting Calendar for Sweet Woodruff

Frost tolerance for sweet woodruff:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Sweet Woodruff tend to make it in mild cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant sweet woodruff in Waterloo 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 sweet woodruff and expect a good harvest is probably September. Any later than that and your sweet woodruff may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sweet woodruff indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Waterloo. It might get as low as -20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Waterloo may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Waterloo it frosts late in the year after April 15 so always be ready to cover your sweet woodruff in the event of a surprise late frost.

USDA Zone Info for Waterloo

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 Waterloo

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