How to Grow Edamame & Sunflowers

Plant edamame seeds and sunflower seeds in late spring as soon as the ground warms and the soil is dry enough to work.

Select a planting spot where the edamame and sunflower plants are exposed to at least six hours of sunlight per day. Both grow in nearly any type of well-drained soil, and neither tolerates soggy soil.

Spade the soil to a depth of 8 to 10 inches. Rake the soil, removing large rocks and breaking up dirt clods.

Make shallow rows, using a garden hoe. Leave 30 to 36 inches between the rows.

Plant edamame or sunflower seeds in the rows, leaving three inches between the seeds. Cover the seeds with 1 inch of soil.

Water regularly, keeping the soil lightly moist until the seeds germinate and the seedlings are showing healthy growth. Don't overwater, as too much moisture rots the seeds. After that time, provide about 1 inch of irrigation every week that it doesn't rain.

Thin the sunflowers when the seedlings are 2 to 4 inches tall. Allow 12 inches between plants for smaller sunflower varieties and two to three feet for larger varieties. Edamame plants require no thinning.

Fertilize edamame when the plants begin to produce blooms. Use a balanced, dry fertilizer with a ratio such as 10-10-10, applied at the rate specified on the container. Sunflower requires no fertilizer -- too-rich soil may result in bushy plants with few blooms.

Spread 3 inches of mulch around edamame or sunflower plants when the seedlings are 4 to 6 inches tall. Use an organic mulch such as dry grass clippings, straw, or finely shredded bark.

Harvest edamame when the pods are bright green and slightly plump but not full. Edamame ripens between 70 and 120 days after planting, depending on the variety and the climate.

Harvest sunflower seeds in autumn when the back of the blooms turn greenish-yellow.