When to Plant Astilbe in Hartland, WI

One of the first steps you take when you are making a decision about 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.

You should be able to estimate when to plant astilbe by looking at the USDA zone info for Hartland.


Planting Calendar for Astilbe

Frost tolerance for astilbe: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since astilbe are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant astilbe
Possibly ok, but a risky time to plant astilbe
Probably not a good time to plant astilbe

The earliest that you can plant astilbe in Hartland 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 astilbe and expect a good harvest is probably August. You probably don't want to wait any later than that or else your astilbe may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your astilbe indoors.

Last Frost Date

In Hartland the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Hartland and it changes from year to year. Half of the time in Hartland last frost occurs after April 15 so always be ready to cover your astilbe in the event of a surprise late frost.

USDA Zone Info for Hartland

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 Hartland

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