One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Maryland Heights you should be able to figure out when you can plant impatiens.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant impatiens until after the last frost has passed because they require warm weather.

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

Last Frost Date

On average the last frost is on April 15 in Maryland Heights. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Maryland Heights is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Maryland Heights last frost occurs after April 15 so make sure that you are prepared to cover your impatiens in the event of a late frost.

USDA Zone Info for Maryland Heights

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Maryland Heights

You may be interested in your other planting guides for Maryland Heights.