Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Gaithersburg should be read to determine when you can plant sweet corn.

Planting Calendar for Sweet corn

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

Sweet corn are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant sweet corn in Gaithersburg 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 sweet corn and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet corn may not have a chance to grow to maturity. If you are starting your sweet corn indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Gaithersburg the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Gaithersburg may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Gaithersburg it frosts late in the year after April 15 so make sure that you are ready to protect your sweet corn in the event of a surprise late frost.

USDA Zone Info for Gaithersburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Gaithersburg

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