Tips on Growing Japanese Maples from Seed.
Collect the seeds in the fall once they start to turn brown. Here in zone 5 that happens near the end of September through October.
Break the seeds apart, there are usually two seeds growing together to form the seed pod. Break of the wing from the seed. After doing this you can store the seeds in a cool dry place until mid winter. Or you can simply sow them in a flat right away and just set the flat outside under a shade tree.
When sowing in the flat in the fall, the flat should contain a good seed starting mix that drains well. Sprinkle the seeds on top of the soil in the flat. Then sprinkle a little soil over the seed. No more than 1/4″ soil over the seeds. Lay a screen (hardware cloth) over the flat to keep the critters from digging in the flat and eating your seeds.
You can use just about anything for a flat, but if you use a cake pan, dish pan etc., you must drill a lot of holes in the bottom so no water stands in the flat. The holes should be at least 1/4″ in diameter and about 1″ on center.
Just leave the flat outside in the cold all winter. The seeds actually need this cold treatment before they will germinate. Come spring you can remove the screen and allow the flat to get more sun. Keep the flat watered, but allow the soil to dry between waterings so the soil has a chance to warm up. You need for the soil to warm so the seeds will germinate.
If you prefer to do the mid winter sowing method just store the prepared seeds in a paper bag in a cool dry place until about mid to late February. Mark your calendar so you don’t forget about them. Mix the seeds with some sand and peat moss or Perlite and peat moss. After mixing together well just put the mixture in a freeze bag and put the bag in your refrigerator. Not your freezer, and not way to the back of your regrigerator. You want the seeds cold, but not frozen.
After 90 days in the fridge take the bag of seeds out and just put them on the counter or other suitable area at room temperature. About 70 degrees. Check the bag every few days for sprouting seeds. As the seeds sprout you can pick them out of the bag and plant the tiny seedlings in a flat of seed starting mix.
The little white tail that appears first is the root, so buy seed root and all. Once the first leaves appear make sure you bury only the seed and not the leaves.
Small Japanese Red Maples should be grown in an area that gets at least 50% shade for the first year or so.
Keep them watered as needed, but do not keep the soil soggy all the time.
Buy Japanese Red Maples for as little as $1.35 each!