One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Marana it's possible to figure out when it's a good idea to plant nierembergia.

Planting Calendar for Nierembergia

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

Nierembergia do not do well in cold weather which means that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant nierembergia in Marana 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 nierembergia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your nierembergia may not have a chance to grow to maturity. Starting your nierembergia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Marana. In the coldest months of winter you should expect an average low temperature of 20°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Marana and it will vary from year to year. Half of the time in Marana there is a last frost after February 15 so make sure that you are ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for Marana

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Marana

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