How Much Sunlight Do Garden Plants Really Need?

As much as you possibly can possibly give them!

There is no real upper limit.

Have you ever seen the pictures of the record crops grown in Alaska? There’s a reason that happens in a place where plants get ridiculous amounts of sunlight during the summer. Garden plants are built to absorb as much sunlight as possible to produce massive amounts of energy and nutrient-rich seeds, fruits, flowers, and leaves during a relatively short growing season.

What’s the Minimum?

Garden plants typically need at least 10 hours of direct sunlight a day. At least! Almost all will be bigger, healthier, and more productive with even more.

Rarely is there too much sun for any garden plant. Tomatoes, peppers, corn, beans, squash, pumpkins, broccoli, and cauliflower—all crops that make fruit or seeds—need massive amounts of energy to produce those fruits and seeds. Some plants that we harvest for their leaves—e.g. lettuce—can get by with a little less, say seven or eight hours, since they don’t need as much energy to produce leaves, but most will do even better if given more. Similarly, cool-season crops, like spinach, broccoli, lettuce, onions, carrots, and peas, do best in cool weather, but that doesn’t mean shade. They still need direct sunlight and will be shells of their possible selves if they don’t get at least 10 hours.

Also, keep in mind that your goal is not to have your plants simply survive but to thrive! Plants that don’t get enough sunlight struggle to not only produce the culinary gems you’re hoping for but also to produce the compounds and barriers that naturally deter and fight diseases and pests. Healthy plants are productive plants, and healthy plants need massive amounts of direct sunlight. If you give them 10-16 hours a day, you’ll be rewarded with healthy, happy, productive plants.

Luckily, complete open horizons will give a grower 13 to 16 hours of direct sunlight a day during the growing season in the contiguous U.S. and southern Canada.

But why do garden plants need so much?