How to Grow Sunflower Plants Indoors

Growing sunflowers indoors can be a challenge.

Sunflower plants bloom with large, yellow flowers that can grow up to 10 feet tall. As a bright sign of summer, it is no wonder that homeowners would like to bring them indoors. If you wish to keep the sunflower indoors throughout its growth, this may present a challenge as the flower needs full sun. Another difficulty may be the size of the flower, although dwarf varieties exist that only grow 2 or 4 feet tall.

Things You'll Need

• Small pots
• Peat
• Perlite
• Large pots
• High-quality potting soil

Instructions

1. Start the sunflower seed in a small pot, planting it 1 inch deep in a mix of half peat and half perlite. Water the plant deeply until water flows out the drainage holes in the bottom.

2. Keep the seeds evenly moist, but not soaked. When the seeds grows to 3 inches, transplant them to large pots surrounded by a high-quality potting soil embedded with fertilizer.

3. Place the sunflower in a east or south facing window where it can receive full sun all day. If you cannot provide this kind of light for the plant, either place the plant outdoors or provide supplemental lighting. If you choose the latter option, start with a cool-white incandescent light and move to a warm-white incandescent light when the sunflower reaches 6 inches.

4. Water the sunflower, keeping it moist until it starts growing vigorously again. Place a 1 to 2 inch layer of mulch on top of the soil. This will conserve moisture for the plant. Only water the plant again when the top of the soil dries.

Tips & Warnings

• Do not water the plant from overhead, as wet leaves lead to molds and fungi.

References

• Washington State University: Sunflower
• Purdue University: Sunflower
• University of Hawaii: Growing Plants Indoors Under Supplemental Lighting