When to Plant Corn in California: All Factors Considered

Corn is extremely easy to grow. But it needs lots of sun, lots of water. Luckily, California has plenty of sun and warmth—which means California is a desirable place for all types of corn to grow in. But not every area in California offers the same climate conditions. So, we need to dig a little deeper for a definitive answer.

When to plant corn in California? In northern California, for example, you might have to wait May in the coldest zones (zones 6 and 7), while corn may germinate since March in the others. Hotter zones in central and southern California would allow for sowing corn in March. But in the South, the lack of precipitation makes planting corn futile in more than half of the available territory.

This scenario repeats itself in other parts of the state. And even some of the hottest areas still may not provide a suitable climate for corn. According to the USDA plant hardiness zone map, California has three distinct zones. Let’s see each region in more detail.

When To Plant Corn In California: North, Central, And South

When to Plant Corn in California

Planting corn outside means avoiding the most damaging elements, starting with frost. If you do not know when your last frost date is, a helpful resource is The Old Farmer’s almanac.

Sowing In Northern California (USDA Hardiness Zones 5-10)

Luckily, northern California is more than extreme drought, forest fires, and heatwaves. But there might be a debate regarding where NorCal begins and ends. For this guide, we will draw the line at Santa Cruz. Anything else lower along the coast is widely considered central California.

Extreme and exceptional drought represents a deadly obstacle to growing corn from the Oregon border to the Bay Area. And according to the U.S. Drought Monitor map, drought progression towards more extreme conditions usually last from spring until late fall.

Sweet corn requires careful attention to detail to achieve high yields, quality, as well as uniformity of maturity and harvest timing. In general, corn emerges from the soil in 4 to 5 days.

Depending on temperatures, it may even take a little longer. The first year and the second year will not yield the same size. So, you might want to switch to planting corn in one year only for better uniformity and quality. Monitor the temperatures at the north and the south side of the bed because they will probably be different.

When To Plant Corn In Northern California?

When to Plant Corn in California

You might have to choose corn varieties through trials, which means you could be looking at more than 200 varieties. After selecting the more apt corn species for your land, start production in mid-April for the best results. Otherwise, wait until May.

Before establishing a crop, it is better to get its bed ready in the fall. And if you work the soil before the winter rains, you could speed up the process. In other words, you could plant the seeds around late February. Or slightly sooner if the soil temperature reaches 50F (10C).

Rip the soil to break up any compaction. Possibly., follow with a disc harrow to prepare the bed. In essence, the more efficient equipment you have to reduce tillage time, the better. Why? Because if you do not go as deep as 3 inches into decent conditions, you may have serious problems getting satisfying corn plants.

Corn needs a lot of water. So, if you do not live nearby a reservoir or a rover, corn might not do so well. Do not get discouraged if the first attempts fail. But be aware that the difficulty level is medium-high. Again, tillage preparation is key.

Sowing In Central California (USDA Hardiness Zones 7-10)

If we start at San Francisco being zero feet at sea elevation and go all the way to Death Valley, the terrain we would go through changes dramatically. The variation in the landscape is why you could go surfing and snowboarding on the same day if you wanted.

Like northern California, the central region suffers from severe to exceptional drought. But the lack of precipitation in the eastern part is the most concerning issue for farmers attempting to grow corn. In general, rainfall only prevails along the coast. But the central part of the state is, arguably, the best place to grow corn.

The soil moisture deficit is partly related to human activities. So, the USDA hardiness zones may not always tell you when to plant corn in California. In any case, let’s see when you can usually plant corn in spring, summer, or fall when it comes to the central part of the state.

When To Plant Corn In Central California?

In most hardiness zones 9 and 10 with mild weather, it is possible to plant corn in February. You can harvest around the 4th of July. And within 24 hours, after you cut it and have the ground turned over, plant corn again.

People living in zones 7 and 8 may start planting corn in March. But it would be better to wait until mid-April for sweet corn.

Sweet corn farmers may start early-season cultivation for weed control. But a great deal of setup adjustment is required for this operation. Without a mechanical cultivator and surface drip irrigation, things can go bad quickly.

Sowing In Southern California (USDA Hardiness Zones 7-11)

Southern California’s climate patterns are complex. In general, it is dry. So, the South Coast is the most hospitable area for corn farming. In other parts, it may be a daunting challenge!

Climate change has had a devastating impact on agriculture in the South. Some scientists even claim California’s future will be drier. Besides, southern California imports large quantities of water from the northern part of the state. On the positive side, water demand has fallen over the past two decades.

When water is not a problem, hailstorms may trash your beautiful plants. But apart from the Santa Ana winds, the wind will take care of corn pollination. The ears will get pollinated properly, and everything else will run smoothly.

When To Plant Corn In Southern California?

People living on the South Coast may plant corn from March to mid-summer. But farming in zones affected by thermal belts or mild marine climate may find it impossible to make corn germinate consistently after March.

The best way for backyard gardeners living in other zones—from zone 7 all the way up to zone 11—is to germinate corn indoors early and then transplant it outside in March. The warm April weather and hopefully some rain in May will do the rest.

If you want to plant sweet corn, sow the seeds in different beds. In the best spots for corn to grow, you may find the corn grains juicy when ready to harvest. Southern California has all the heat corn can desire. So it is just a matter of consistent watering and plant transpiration control.