Even in areas with a short growing season, you can grow the hyacinth bean vine from seeds. After starting indoors before the last frost, it will propagate and spread rapidly outdoors, reaching a length of 15 to 18 feet on supports. Here are guidelines on how to prepare hyacinth bean seeds for transplanting outdoors.
Step 1: Prepare the Seeds for Germination and Plant in Pots
Soak seeds overnight submerged in warm water above 70 degrees Fahrenheit to start the germination process. Prepare pots with moist potting soil, and set one seed per pot just under the soil surface. Set the pots in a location that gets 6 hours of sunlight per day. Keep the soil at room temperature, and water as needed to keep the soil moist.
Step 2: Prepare the Garden Bed to Plant the Strongest Seedlings
Once nights are frost-free, move the seedlings out to the garden. Have supports ready for twining the vines as they will shoot up quickly. In loosened soil mixed with sand or fine gravel for drainage, blend in compost and leaf mold to a depth of 2 inches. Add 5-10-10 low nitrogen fertilizer, and plant the seedlings 12 inches apart, with a 1/8-inch soil covering. Moisten the soil daily until the seedlings are established.
Step 3: Maintain the Vines
Water the vines as needed to prevent wilting. Each month, apply a mulch of leaves and lawn shavings, and add fertilizer at half-strength in a high-low phosphorus and nitrogen blend. Potash is also beneficial to hyacinth bean vines. Train the vine tendrils onto the supports when the vines reach 18 inches in length.
Step 4: Protect from Pests
Rabbits consider hyacinth bean plants a delicacy. To protect them, cover the seedlings with bird netting until mature leaves have formed.
Step 5: Check for Insects and Disease
The sharp wiry hairs on hyacinth bean leaves serve as ample defense against most insects and airborne disease spores. Ensure soil does not become soggy as this promotes root rot.
Step 6: Autumn Removal
Collect seeds in late summer after the flowers have faded, and start the next batch in late winter near the final weeks of ground frost. When the vines die back after frost, remove them and compost.
In warmer frost-free areas, plant the seeds directly into warm soil in late spring, and allow them to self-seed. Dig out weaker vines to prevent overcrowding.
The hyacinth bean vine adds color and scent to gardens, drawing butterflies and hummingbirds to feast on the nectar from its purple or white flowers. Elegant twining purple stems support the flowers, shaded under broad green leaves. Hyacinth bean pods are edible and can be cooked in many different ways. Raw hyacinth beans do have toxic elements, so boil them thoroughly before preparing in recipes to eat. Early seedlings can also be harvested and cooked in dishes that call for bean sprouts.