Maple trees come in a variety of species, and each species produces its own unique seed. The silver maple and red maple seeds are mature in late spring to early summer. The sugar maple seeds aren't ready until late summer to early fall. It is recommended to stratify the seeds prior to planting. This means to subject the seed to cool, wet conditions. Maple seeds need 90-120 days of stratification.
Collect seeds that have fully matured according to their time line. Silver maple and red maple seeds mature in spring to early summer. Sugar maple seeds mature in late summer to early fall.
Put the seeds in a closed container filled with moist sand or peat. Store them in a refrigerator set at 33 to 39 degrees F for 90 to 120 days. Check on them occasionally to make sure the soil stays moist but not wet.
Gather a few small pots to plant your seeds in. Fill them 3/4 of the way full with a well-draining potting mix.
Sow one seed per pot. Cover the seed with 1/4 inch to 1 inch of soil.
Water the seed until the soil is moist. Continue to check daily to make sure the soil stays moist. Germination should occur within a few weeks.