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

One way of getting a good idea when it's a good idea to plant gladiolus is to consult the USDA zone info for Manhattan.

Planting Calendar for Gladiolus

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

Gladiolus are barely cold tolerant which tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

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

Last Frost Date

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

Since the USDA zone info for Manhattan is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Manhattan you get surprised by a frost after April 15 be ready to protect your gladiolus in the event of a surprise late frost.

USDA Zone Info for Manhattan

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Manhattan

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