The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Altoona you can determine when it's the best time to plant marigold by looking at the USDA zone info.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant marigold until after all chance of frost has passed because they require warm weather.

The earliest that you can plant marigold in Altoona 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 marigold and expect a good harvest is probably August. If you wait any later than that and your marigold may not have a chance to fully mature. If you are starting your marigold indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Altoona. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Altoona is an average the actual date of last frost will vary from year to year. Half of the time in Altoona there is a last frost after April 15 so just be sure to be ready to protect your marigold if you have a surprise late frost.

USDA Zone Info for Altoona

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 Altoona

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