One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 Presidio should be reffered to in order to figure out when it's the best time to plant iresene.

Planting Calendar for Iresene

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

Iresene require warm weather which tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant iresene in Presidio 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 iresene and expect a good harvest is probably September. If you wait any later than that and your iresene may not have a chance to grow to maturity. If you are starting your iresene indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Presidio. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Presidio is not always accurate the actual date of last frost changes from year to year. Half of the time in Presidio it frosts late in the year after February 15 so always be ready to protect your iresene in the event of one of those late frosts.

USDA Zone Info for Presidio

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 Presidio

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