Propagation Procedures for a Western Redbud Tree

Timing

• Western redbud seeds stay viable for up to 12 years, thanks to their hard, impermeable seed coat. However, they must be gathered immediately after they ripen in autumn to limit the chances of insect damage and pathogenic growth. Collect the seeds once the pods turn light brown and rattle when shaken. Keep the seeds inside a paper bag under dry, cool conditions until spring, when they can be pretreated and sown.

Seed Pretreatment

• Pretreating Western redbud seeds takes roughly three months, so it is best to start the process in late winter or very early spring. It involves scarification to weaken the seed coat and stratification to fulfill the seed's dormancy requirement. The seeds can be nicked with a nail file or soaked in boiling water overnight to weaken the seed coat. Both methods work equally well, although the water soak is less labor intensive. Once scarified, the seeds must be cold stratified. Store the seeds in moistened peat moss inside the refrigerator for two to three months. Check the peat moss regularly to ensure it remains moist.

Sowing

• Sowing Western redbud seeds in containers rather than nursery beds will limit the chances of damping off, a devastating fungal infection common in many seedlings. Larger, 1-gallon pots are best because they allow the seedlings to put down a long taproot, which will help them survive in the ground. Sow one seed in each pot at a depth of roughly 1/4 inch, which is approximately three times the width of the seed. The soil covering the seed should be lightly tamped to help anchor the seed to the soil.

Germination Conditions

• Outdoor germination will result in healthier, more robust Western redbud seedlings because the freely circulating air and fluctuating temperatures discourage the growth of potentially harmful pathogens. A lightly shaded, sheltered area is ideal, although the pots can be placed inside an open cold frame if daytime temperatures stay below 70 degrees Fahrenheit for an extended period of time. Consistent moisture is essential, so keep the top inch of soil moderately moist. Because the seeds are shallowly sown, water with a fine mist or spray nozzle to keep from dislodging the seed. Healthy Western redbud seeds will germinate in roughly one to two weeks if daytime temperatures stay consistently above 70 F.

Aftercare and Planting

• Although Western redbuds grow quickly, they must still be grown in pots under sheltered conditions for one full year before they're planted in the ground. Infections are still a threat during the establishment phase, so keep them under the same sheltered yet airy conditions, and water them at the base rather than spraying from the top. Acclimate them to full sun for at least two weeks before planting them in a sunny bed in spring or autumn of their second year.