When to Plant Iresene in San Jose, CA

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

You should be able to estimate when to plant iresene by referring to the USDA zone info for San Jose.


Planting Calendar for Iresene

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

Iresene are not cold tolerant which means that it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant iresene
Possibly ok, but a risky time to plant iresene
Probably not a good time to plant iresene

The earliest that you can plant iresene in San Jose 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 fully mature. If you are starting your iresene indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In San Jose the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Always keep in mind that USDA zone info for San Jose is not always accurate and the actual date of last frost is different every year. Since half of the time in San Jose you get surprised by a frost after February 15 be ready to cover your iresene if you have a late frost.

USDA Zone Info for San Jose

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low25°F
Highest Expected Low30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Jose

You may be interested in your other planting guides for San Jose.