MAPLE SEEDS 

Growing Maple from Seeds

1. Fill a plastic bag with growing material. Place a handful of peat moss, vermiculite , or germination paper in a small, plastic, zip-locked bag. For best results, use sterile material and handle it with disposable gloves to avoid introducing fungus.
2. Add a little water. Add a couple drops of water to the growing material to dampen the material slightly. If you see standing water, or if you can squeeze out water from the material, it is too wet.
3. Apply a little fungicide (optional). Fungicide can prevent mold from destroying your seeds, but it is not always necessary, and may damage the plant if overused. Add only in tiny quantities, following manufacturer's instructions.
4. Add the seeds and close the bag. Place up to 5 or 10 seeds in each bag. Starting from the base, roll the bag to expel most of the air. Zip it closed.
5. Store in the refrigerator. Now it's time to "stratify" the seeds, or expose them to temperatures that trigger germination. For most species, the ideal temperature is usually around 1–5ºC (33.8–41ºF). The crisper drawer of a refrigerator is usually about this temperature. Ideally, use a thermometer to confirm the correct temperature. Some seeds may fail to germinate if the temperature is just a couple degrees off.
6. Leave them for 40–120 days, checking every week or two. Most of these species take 90–120 days to germinate, but the bigleaf maple and a few others can sprout in as few as 40. Every week or two, check on the bag and make adjustments as needed: If you notice condensation, pick up the bag and gently tap it to knock the water droplets off. Lay the bag back down on the opposite side, so the wet seeds have a chance to dry off. If the growing material has dried out, add a drop or two of water. If you notice any mold or black spots, remove that seed and throw it away. (If the whole batch is molding, try a little fungicide.) If the seeds have begun to sprout, remove them from the refrigerator.
7. Plant the seeds. Once the seeds have germinated, plant them 0.6–1.2cm (¼–½ inch) under moist soil. Most maples do well in partial shade, but look up the exact species if possible for more info on planting. To increase the odds of survival, start the seedlings in an indoor seed tray instead. Fill the tray with 7.6–10 cm (3–4 inches) of well draining seed starter, or an even mix of peat moss, rotted compost, vermiculite and coarse sand. Water whenever the soil becomes completely dry. Transfer to planter pots once the second set of leaves appear.