When to Plant Iresene in Hillsboro, OR

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

One way of estimating when to plant iresene is to consult the USDA zone info for Hillsboro.


Planting Calendar for Iresene

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

Iresene do not do well in cold weather which tells us 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 Hillsboro 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Hillsboro. In the coldest months of winter you can expect an average low temperature of 15°F.

Always keep in mind that USDA zone info for Hillsboro is an average and the actual date of last frost changes from year to year. Since half of the time in Hillsboro you get a frost after March 15 be ready to protect your iresene in the event of a surprise late frost.

USDA Zone Info for Hillsboro

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 Low15°F
Highest Expected Low20°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 Hillsboro

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