To propagate white ash trees, you can use cuttings (hardwood or root), layering, or seeds, with cuttings and layering being more reliable than seeds.
Here’s a more detailed breakdown:
1. Cuttings:
- Timing: Late fall or early winter is ideal for taking hardwood cuttings from dormant trees.
- Selection: Choose healthy, pencil-thick root cuttings or suckers (branches growing from the roots).
- Preparation: Cut root cuttings into 2-6 inch segments.
- Dip the cut end in rooting hormone. Plant in a mix of perlite and soil, ensuring the top end is just below the surface.
- Care: Maintain consistent moisture without overwatering, and keep cuttings in a cool, shaded area.
2. Layering:
- Timing: Summer (June-August) is a good time to propagate from suckers.
- Method:
- Find “sucker” branches growing from the roots or lower trunk.
- Plant the sucker in a well-drained pot with soil and mulch.
- You can add rooting hormone to encourage growth.
3. Seeds:
- Collection: Collect seeds (samaras) from healthy trees in late summer or early fall.
- Pretreatment:
- Soak seeds in cold water for 48 hours, changing the water after the first day.
- Mix seeds with equal parts horticultural sand or a sand/compost mixture.
- Stratification:
- Store the seed/sand mixture in a pot outdoors for 18 months.
- Water the pots if they show signs of drying out and protect from birds and mice.
- Sowing: Sow the seeds in the second spring following collection.
Tips for Success:
- Vigor: Use cuttings or suckers from vigorous and robust parent plants.
- Rooting Hormone: Applying the right concentration of rooting hormone can significantly enhance root development.
- Patience: Ash seeds can take several years to sprout, so be patient.
- Seed Stratification: Stratifying seeds (storing them at cool temperatures) can help them sprout more quickly.
- Protection: Protect seedlings from animals and harsh weather.