Growing your own Japanese Maple from seed is a very rewarding experience. What could be better than seeing a seed sprout and become a little twig, and then grow into a beautiful tree? The secret to starting your own tree from seed is something called layering. This is where you trick the seeds into thinking they’ve been through a freeze/thaw cycle; also known as winter. Here are 5 simple steps to get you on your way:

1. Start with fresh seed. Fresh seed increases the probability that the seeds will be viable. As seeds age, the chances of them germinating decrease. Collecting seeds from a local tree is a great way to ensure you start with fresh seeds, but be sure to ask permission first! When the seeds have turned a reddish-green color, they are ready to harvest. One thing to remember with ANY Japanese Maple seed: there is no guarantee that you will get the same color as the tree from which the seed was collected. A seed from a red Japanese maple will usually be red, but there is also the possibility that it is a cross between a red and green tree, which can produce a tree that has traits from both parents. But this is the exciting part; your tree will be unique! You can also buy small quantities of seeds on Ebay, but be sure to confirm that they are the current year’s crop.
2. Determine what the “last frost date” is for your area. This is the day in spring when it is generally safe to start planting gardens. In Maine, it’s usually right after Memorial Day. Now count down 120 days. This is the approximate number of days the seeds will need to germinate. This is the date that the stratification process will begin. Some seeds may not germinate until much later than 120 days, but be patient, some seeds are only late bloomers, or are they germinators?
3. On or around the date you determined in step 2, fill a cup with hot water from your tap, but don’t use extremely hot water. If hot water steams when it comes out of the faucet, it may be too hot. Simply adjust the temperature with cold water. If the water is too hot, it will kill the seeds. Don’t overfill the cup, you need room to add the seeds. Pour your seeds into the cup and let everything sit for 24 hours.
4. Most of the seeds will now be at the bottom of the cup. The seeds have absorbed water and have now started the germination process. Remove these seeds and place them in a small bag containing moistened sand, peat moss, vermiculite, or a combination of these. The exact mix isn’t extremely important, just make sure it’s damp and not wet. Personally, I’ve had better luck with vermiculite, and it’s easier to find the seeds when planting them, but go ahead and use what’s easiest for you. Poke a few holes in the bag with a fork to allow air to circulate. Put the bag in the refrigerator. I put mine on the door, or in the drawer. Be sure to put them somewhere where you can see them. You’ll need to check on them from time to time, and if they get pushed behind something, you might forget about it. Check the bag from time to time to make sure the sand, peat moss, or vermiculite is still moist, and add water if necessary. Opening the bag to check for moisture also exchanges the air in the bag, helping to kill mold and mildew. If mold or mildew is present, don’t panic. Simply rinse the seeds with a 50/50 mixture of water and hydrogen peroxide, and return them to a baggie with fresh, moist sand, peat moss, or vermiculite.
5. As the seeds begin to sprout, you will see little white “tails” coming out of the seeds. You are getting closer to growing your tree! You can choose to plant the seeds outside after the last frost, or use whatever method I’ve found works best for me. Either way it works, but I’ve found that I don’t have much control over the weather and it’s sometimes uncooperative. There have been times when my seeds were ready to plant outside, but the ground was still frozen. I couldn’t do much about it! I decided to plant the seeds in individual peat pots. You already know the; the ones that swell when you pour water on them. Make a hole in the top of the pot with a pencil and place the seed in the hole. Keep the pots moist, but not wet. This method gives you a little more time for the weather to cooperate. Be sure to give the plants plenty of light when they start to develop leaves. I use a fluorescent light suspended above the plants, but a bright window works just as well, and be sure to rotate the plants if they start to bend toward the light. Another thing to keep in mind is something called damping. This is when the plant dies and rots near the soil line. It is caused by a fungus that lives in the soil and is usually due to a lack of air circulation and excessive watering. If I find seedlings showing wilting, I remove them from the area to reduce spread, adjust airflow with a fan, and reduce watering frequency. When you can work your soil outside, simply plant the pots in the ground. I plant mine in a bed I made to grow the plants for a while until I can transplant them to sell. For seeds that have not germinated, plant them in a shaded bed about 3/8 deep, watering occasionally. Save them for next year, and see if any have sprouted.

New Japanese maples should be shaded for the first year or two to minimize the chance of sunburn. For small numbers of plants, you can build a small lattice cage that provides shade. For larger numbers, a trellis suspended over the plants on a wood or cinder block frame is an option, but a shade cloth may be a better option. After the plants have grown for a few years, they can be transplanted into their permanent home. Be sure to dig up and transplant the trees after they are dormant to ensure their survivability.

Congratulations! You now have a beautiful Japanese Maple that you can enjoy for years to come, and you can even tell everyone who comments on it that you grew it yourself!