The black-eyed susan flower (rudbeckia hirta) grows best in full sun. Full sun is defined as at least 6 hours of direct sunlight per day. Black-eyed susans can tolerate partial shade, but 6–8 hours of sunlight really is ideal for these yellow flowers. This is good because the black-eyed susan has low heat tolerance so shade can help protect it in late summer. They can also handle indirect sunlight but will need at least 8-10 hours of it to make up for the lack of direct light.
How Many Hours of Sun Do Black-Eyed Susans Need?
Black-eyed susan plants need at least 6 hours of direct sunlight per day. These showy flowers are a staple of many a summer garden since they require warm weather and bright light to bloom.
- 6–8 hours of daily direct sunlight is ideal for black-eyed susans.
- Black-eyed susan flower heads need warm temperatures and bright light to produce their best blooms.
Black-eyed susans can grow up to 6 feet (1.8 meters) in height, which makes them impressive to behold. If you want to add them to your summer garden, just make sure they’re given a bright patch to grow. You want to maximize the amount of light the flower heads get for the most dramatic blooms
Can Black-Eyed Susans Grow in Indirect Sunlight?
A black-eyed susan can grow in indirect sunlight but it will need more light to make up for the lack of direct sunlight. 8–10 hours of indirect sunlight should be sufficient for your black-eyed susans. This ability to deal with indirect sunlight makes these showy flowers ideal houseplants.
- Black-eyed susan plants can grow in indirect light.
- Substitute 8–10 hours of indirect light for 6–8 hours of direct sunlight.
- Black-eyed susan make great houseplants.
Be sure to give your potted plants a sunny spot to grow. A south-facing window would be ideal for growing your black-eyed susan vine. You may want to get a dwarf variety black-eyed susan seeds to avoid having a 6-foot tall potted plant though.
Can Black-Eyed Susans Grow in Shade?
Partial shade is tolerable to black-eyed susan flowers. Black-eyed susans do prefer full sun but some afternoon shade will not be harmful. In extremely hot conditions, black-eyed susans can be helped by partial shade.
- Partial shade is tolerable to black-eyed susan plants.
- Shade can help black-eyed susans deal with excessive heat.
This is because the black-eyed susan vine is susceptible to extreme heat. Extreme heat can kill a black-eyed susan vine and result in dead flowers. Dappled or light shade is a good way to protect these plants from high heat.
What Happens if Black-Eyed Susans Don’t Get Enough Sun?
A lack of sun will severely weaken and may even kill your black-eyed susans. All flowers need to convert light to energy through photosynthesis. Not getting enough means your plant will be undernourished. This can result in leaf spot, fungal diseases, and root ball rot. At best, lack of sunlight will stunt your black-eyed susan’s growth. It won’t grow as tall as you’re hoping if it’s not getting enough light.
- Black-eyed susans grow best in full sunlight.
- Undersunned black-eyed susans are at increased risk of disease.
- Stunted growth is a common side effect of lack of sunlight.
Since a black-eyed susan vine can grow up to 6 feet tall (1.8 meters), it would be a shame to not see it reach its full glory. Be sure your black-eyed susan gets plenty of sunlight to avoid these issues. Well-sunned plants are healthy plants and disease resistant. If you want to increase your plant hardiness, always keep your black-eyed susan well-sunned.
Can Black-Eyed Susans Get Too Much Sun?
Too much sun is not a concern but too much heat can be harmful to the growth of your plants. Black-eyed susan seeds germinate and eventually flower best when soil temperatures are near 70℉ (21℃). Soil temperatures are typically ideal for black-eyed susans when daytime highs are around 80℉ (27℃). Black-eyed susans are considered a hardy plant that is very cold-tolerant, but they don’t handle the heat as well as they handle cold.
- Excessive sunlight does not harm black-eyed susans, but too much heat does.
- Daytime highs of 80℉ (27℃) are ideal for black-eyed susans.
- In extremely hot temperatures, black-eyed susans can struggle and die.
- If your black-eyed susans are wilting in the heat, provide extra water and some afternoon shade.
High heat periods like midsummer can scorch your black-eyed susans, ruining their blooms. Be sure to plant black-eyed susans somewhere with dappled shade if you live in a high heat region. This will provide protection against high heat. If you can’t provide natural cover, consider using this row cover to protect them from the afternoon sun when temperatures rise above 80℉ (27℃).
How Much Sun Do Black-Eyed Susans Require?
Black-eyed susans require 6 hours of direct sunlight every day. This is because they are sun-loving plants that flower in late spring and early summer. They love warm climates and ample sunlight. But this does come with a downside. Let’s go over the key things to remember about the sun needs of black-eyed susans:
- Black-eyed susan plants need full sun (6 hours of direct light each day).
- Black-eyed susans can tolerate partial shade, which can be sued to protect theme roma afternoon heat.
- Susans that don’t get enough sun are at increased risk of becoming diseased.
- Susans can’t get too much sun can die in temperatures over 80℉ (27℃).
Black-eyed susans grow best in sunny garden beds. If you have a mild climate, you can plant them wherever they’ll receive the most sun. If you live somewhere hot, consider planting them in a garden bed near shade. This will preserve the flowers’ beautiful blooms for you to enjoy throughout summer.