When to Plant Four-o-clock flower in Monmouth, OR

One of the best tools that you have as gardeners to help us determine 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 first opportunity to plant four-o-clock flower in Monmouth should be estimated by reviewing the USDA zone info.


Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower: Not tolerant of frost.
When to plant: After the last frost.

Four-o-clock flower do not do well in cold weather which means that it's 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 four-o-clock flower
Possibly ok, but a risky time to plant four-o-clock flower
Probably not a good time to plant four-o-clock flower

The earliest that you can plant four-o-clock flower in Monmouth 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 four-o-clock flower and expect a good harvest is probably August. If you wait any later than that and your four-o-clock flower may not have a chance to grow to maturity. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Monmouth and it is different every year. Half of the time in Monmouth there is a last frost after March 15 so always be ready to protect your four-o-clock flower if you have a surprise late frost.

USDA Zone Info for Monmouth

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 Monmouth

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