When to Plant Romaine lettuce in Glendora, CA

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant romaine lettuce in Glendora should be figured out by checking out the USDA zone info.


Planting Calendar for Romaine lettuce

Frost tolerance for romaine lettuce: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Romaine lettuce do well in cold which tells us that you can get them planted much earlier than other frost tender plants.

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

The earliest that you can plant romaine lettuce in Glendora is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant romaine lettuce and expect a good harvest is probably October. Any later than that and your romaine lettuce may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

On average the last frost is on January 31 in Glendora. In the coldest months of winter you should expect an average low temperature of 30°F.

Just be sure to remember that USDA zone info for Glendora is just an average and the actual date of last frost is different every year. Half of the time in Glendora you get a frost after January 31 so make sure that you are prepared to protect your romaine lettuce if you have a late frost.

USDA Zone Info for Glendora

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low30°F
Highest Expected Low35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Glendora

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