Acer Negundo - Seeds and Germination
Germintion rate of Maple is highly variable. It's 20-70%
If you sow the seeds just after picked them up you don't have to treat them. Previous treatments are needed when you save the seeds.
This specie needs cold stratification. So we have to put the seeds in wet sand under low temperatures, 2-5ºC for 30-120 days.
The ideal substrate is a sandy one. When the seeds have grown enough put them in a better soil.
Put the seeds on the substrate, leaving two cm between them.
Cover with a layer of soil equal to the thickness of the seed.
The seeds may sprout while they are in the cold stratification. After that, put the seeds in a warmer and illuminated place.
For all that time we have to keep constant moisture and temperature.