One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when to plant iresene by looking at the USDA zone info for Columbia.

Planting Calendar for Iresene

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

It's probably not a good idea to plant iresene until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant iresene in Columbia 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 iresene and expect a good harvest is probably August. 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

In Columbia the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Columbia and it can change quite a bit from year to year. Since half of the time in Columbia it frosts late in the year after March 15 be ready to cover your iresene if you have one of those late frosts.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Columbia

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