Tomatoes are fast-growing plants that can double in size in as little as two weeks during their initial growth phase. For this reason, they require lots of energy from sunlight, soil nutrients, and water. Tomatoes originated in warm regions like Central and South America, evolving in sunny conditions that the plants still prefer to this day. However, it’s possible to enjoy homegrown tomato crops even if conditions aren’t perfect. Here’s what home gardeners need to know.
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How Many Hours of Sun Do Tomatoes Need?
Like many sun-loving plants, tomatoes require a minimum of six hours of full sun per day for healthy growth and to produce fruit. However, gardeners who are able to provide outdoor conditions for their tomato plants with eight or more hours of full sun per day are rewarded by an increased bounty of tomato fruits.
- Tomatoes perform best with at least six hours of sunlight per day.
- The more sun they get, the more fruit the tomato plants produce.
- The hours of sunlight tomato plants receive don’t have to be consecutive.
The hours of direct sunlight do not need to be consecutive. For instance, tomatoes can be successfully sited in garden spots that receive both morning and afternoon sun as long as the total direct sunlight received adds up to at least six hours per day.
Can Tomatoes Grow in Indirect Sunlight?
Whether tomatoes can grow and produce fruit in indirect sunlight depends on the amount and quality of the sunlight. Tomato plants may do well in bright, indirect sunlight such as dappled sunlight provided by deciduous trees with high canopies, but the same plants are likely to struggle if planted on the north side of the house or outbuilding or under a dense shade tree. As a general rule, tomatoes that are grown in indirect sunlight produce less fruit than tomato plants that receive at least six hours of direct sunlight per day.
- Tomatoes can grow well in indirect sunlight as long as the shade is light or dappled.
- Heavy shade or north-facing plantings will cause tomatoes to struggle
- Some tomato varieties—such as cherry tomatoes—grow well with less sunlight than other tomatoes.
Some varieties of tomatoes require less sun than others. Most varieties of cherry tomatoes, for instance, perform fairly when grown in locations with less than ideal amounts of sunlight. There are also a few classic varieties that have been proven to produce an acceptable amount of fruit when grown in bright, indirect sunlight.
Can You Grow Tomatoes in Shade?
Growing tomatoes in the shade is difficult, but not impossible, as long as the plants receive some direct sunlight or it’s dappled shade. Choosing the right tomato variety is important — as mentioned previously, some types of tomatoes are more shade-tolerant than others. However, because water doesn’t evaporate as quickly in shaded conditions as it does in direct sunlight, fungal pathogens are frequently an issue. Providing trellises, placing plants farther apart, and taking care not to let the foliage and lowest leaves get wet during watering are recommended to keep plants healthy and producing. However, gardeners should keep in mind that tomato plants grown in shady areas will be leggier than normal and will not produce as much fruit.
- Tomatoes can be grown in shaded locations.
- Fungal pathogens are a problem when growing tomatoes in shade.
- Tomatoes don’t require sunlight for fruit to ripen.
The good news is that although tomatoes require a certain amount of sunlight in order to flower and set fruit, direct bright light isn’t necessary for the fruit to ripen. The two factors necessary for ripe tomatoes are heat and ethylene gas. Getting plants to the flowering stage is the real challenge for those growing tomatoes without the benefit of abundant sunlight — after that, the amount of sunlight the plants receive plays a smaller role.
What Happens if Tomatoes Don’t Get Enough Sun?
Tomatoes that don’t get enough sun produce smaller yields and become leggy and tall during the growth phase as they try to reach the sunlight. The stems and foliage may also be paler than they otherwise would be if they don’t get enough sun. The plants may also fall victim to fungal diseases, such as powdery mildew. This is because lack of exposure to direct sunlight promotes damp conditions where fungal colonies thrive. To combat this problem, gardeners must provide shaded tomatoes with good air circulation.
- Tomatoes become tall and leggy without enough sun.
- Good air circulation is important for tomatoes that don’t receive ideal amounts of sun.
- Gardeners can make up for the lack of sun in a variety of ways.
Besides providing good air circulation, those who site tomatoes in spots that receive less than six hours of sunlight per day can optimize their chances of a successful harvest by providing plants with rich, well-drained soil, ample amounts of water, and good drainage.
Can Tomato Plants Get Too Much Sun?
Although tomatoes typically thrive in full sun, intense sunlight coupled with excessive heat can cause a condition known as sunscald. Sunscald presents as grayish-white or yellow patches on the surface of the fruit and typically appears on the parts exposed to the sun. Areas affected by sunscald are more vulnerable to damage by insect pests and pathogens.
- Intense heat and sun cause a condition called sunscald.
- Sunscalded tomatoes are more susceptible to damage by insects and disease.
- Protect scalded tomatoes from the heat of summer with a shade cloth.
When caught in its early stages, the progression of sunscald can be slowed by placing a physical barrier, such as a shade cloth or screen, over the fruit to shield it from the sun. Gardeners can also pick affected fruit and allow it to ripen indoors, cutting out the sunscalded area prior to use. It’s best to be proactive if you expect any heat waves to come through so you can grow healthy tomato plants.
How Much Sunshine Do Tomatoes Need?
Although tomatoes produce the most fruit and are less vulnerable to pests and disease when they have more than six hours per day of direct sunlight, they’re adaptable plants that can thrive in less than ideal conditions. There are many ways that gardeners can make up for not being able to provide perfect sun exposure, such as providing good air circulation, rich, well-drained soil, and enough water.
- Tomatoes can be grown even without full sun.
- Tomatoes can perform well in indirect sunlight.
- Growing tomatoes in shade is challenging but not impossible.
In conclusion, most home gardeners can grow tomatoes even if they don’t have the perfect spot for them in the garden. When you plant tomatoes, consider how much bright light they get and determine if you’ll need to take extra steps to prevent fungal disease.