Yes, sunflowers can grow in shade but won’t flourish. Planting sunflower in shade will result in stunted flowers, and seeds won’t grow well.
As their name (sun) suggests, sunflowers require the abundant sun to grow properly.
The plant is native to Central America, where it prospers in warm, sunny conditions. That’s why it’s recommended to plant sunflowers in late spring, where they will get at least 6 hours of sunlight.
Sunflowers can grow in shade areas, but don’t expect a bountiful harvest if you do that.
For the best results, a sunflower needs 6 to 8 hours of sunlight. Therefore, you should plant sunflowers in an open area where they receive abundant sunlight from the morning to evening.
What Happens When You Plant Sunflowers In Shade?
Sunflowers have heliotropic qualities. This means that they follow the path of the sun. However, this applies only to the sunflower’s buds. They face the east when the sun rises and follow the sun to the west as it sets.
After the plant blooms and stem hardens, the flowers face the east and no longer move with the sun.
So, if the plant is not receiving enough sunlight because of shade, it will not bloom well. As a result, it will lead to stunted growth. The plant will be weak and unhealthy.
Low Seed Production
If sunflower is grown within the right conditions, it should produce at least 1, 000 seeds. These seeds are edible and are used for a variety of purposes around the world.
But if the conditions are not right, such as low light or shade, expect to have a bad harvest. You will harvest fewer seeds than a person who grows the plant in full sunlight.
Risk Of Fungal Infection
Sunflowers are vigorous plants that can defy harsh conditions and flourish. They can grow in different types of soils as long as they receive enough nutrients and water. They can also grow in shade areas, but you will risk losing your plant or having a lower production.
One of the disadvantages of planting sunflowers under shade is exposing them to diseases. A fungal disease such as Phoma blight thrives in wet conditions.
Therefore, if your plant is not getting enough sunlight, it may be attacked by this fungal disease.
Phoma blight attacks the plant when it starts flowering. You may notice black lesions on the stem. Also, you may see dark-colored, poorly shaped lesions show up on leaves and flowers. This fungal infection may cause your plant to die or produce little seeds.
Apart from Phoma blight, other diseases that might attack your plant in shade areas are powdery mildew and white mold. With enough sunlight, none of these diseases will survive. The sunflower will dry out dew that gathers at night and attract the parasites that cause these diseases.
Sunflowers are known as one of the best pollinators. These plants feature tall and brightly colored flowers that attract insect pollinators from a distance. Because of their outstanding visibility, bees, moths, wasps, beetles, and butterflies fly from far to land on the plant.
What attracts these pollinators is the colorful petals of the sunflower and the warmth of the daily sunlight. Thus, if you plant the sunflower in a shaded area, the pollinators won’t detect or get attracted to the plant easily.
This will hinder pollination to some extent. In the end, they will affect the production of seeds, which is the primary purpose of sunflowers.
What Else Do Sunflowers Need Apart From Sunlight?
Sunflowers is a hardcore plant that can survive in tough weather. However, you need to plant it in favorable conditions before it attains the hardcore level. Young sunflowers are weak and need proper conditions to grow.
The best time to plant sunflowers is after the danger of frost has passed. Additionally, the soil temperature should be 70 degrees to 75 degrees F. On top of that, you should sow the seeds when the soil temperature is 55 degrees F or warmer.
Sunflowers may be drought and heat tolerant, but they need frequent watering to flourish. Sunflower needs even more water in the early stages of growth. The seeds should be watered daily to keep the soil moist for proper development.
A young sunflower should be water after every few days, more so if the soil is hot and dry. When the plants start to strengthen, and the flower becomes established, water only once a week. Do not water the leaves or flowers, but at the base of the plant. This will discourage disease build-up.
As stated earlier, sunflowers can thrive in various types of soils. They don’t need a lot of nutrients to survive. But if your soil is poor in nutrients, you can add some fertilizer to it. If you have compost, it will be the best solution.
Add it on top of the soil. But if you don’t compost, acquire slow-release fertilizer and apply it in the same way. Avoid adding fertilizer close to the plant as excess nitrogen may delay flowering.
Control Pests And Diseases
Like any other plant, sunflowers will also attract pests and diseases. Things like snails, slugs, squirrels, birds, and deer will want to feed on your plant.
Apply repellents for slugs and snails, create a fence for squirrels and deer, and keep your plant well moist to prevent diseases.
Whether you plant a sunflower for its beauty or as a food source, you need to ensure that the conditions are right. Sunflowers can grow in the shade but won’t grow to their full potential. What’s more, growing sunflower in the shade exposes it to many diseases and pests.
Sunflower needs at least 6 hours of full sunlight to grow to their full potential. Also, with enough light, the plant will fight off fungal infections and different diseases. It will also attract pollinators, which are crucial for the multiplication of sunflower.
Therefore, plant your sunflower where it gets 6 to 8 hours of sunlight and not in a shaded area.
Even if you’re growing sunflower indoors, ensure to place it close to a south-facing window where it gets enough light. Apart from sunlight, ensure that the plant receives the right fertilizer, water, and proper care.