How to Plant Wisteria Seeds

Rub the wide bottom (opposite to the seed's point) or each seed gently against the sandpaper to expose the inside of the seed. Stop right after you have broken through the surface. Alternately, soak the seeds in a bowl of warm water for 24 hours. These processes weaken the seed's hard coating and enable them to sprout quickly. Failing to do so will make it hard for the seed embryo to break through the hard shell. In nature weather prepares the seeds when they are in the ground over winter by freezing and thawing them.

Plant the seeds indoors six to eight weeks before the last frost, according to Eileen Powell in "The Gardener's A-Z Guide to Growing Flowers from Seed to Bloom." Do this by preparing individual pots or a single large plant tray with potting soil. Water the soil and add more dirt to make up for the compaction. Press the seeds into the soil and bury them one inch deep. Place the pots or trays in a cool room with temperatures between 55 and 65 degrees Fahrenheit. An ideal place would be an unheated laundry room that gets indirect heat from the house. Provide the plants access to sunlight through a window or place a fluorescent plant light over them for at least 12 hours per day. Transfer the seedlings immediately after the last frost to a sunny outdoor area. Transfer one seedling per bed or area.

Plant prepared seeds directly outdoors at a depth of one inch in early spring or late autumn. The naked seeds will not be harmed by the threat of a gentle frost before they sprout. Use one seed per tree that the wisteria will be trained around or one per side if they will be twined into an arch or pergola. The wisteria will sprout in 30 to 35 days.