Growing your own Japanese maple from seed is a very rewarding experience. What could be better than watching a seed sprout into a tiny 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 gone 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 likelihood that the seeds will be viable. As the 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 reddish-green, 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 from 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 a 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 the “last frost date” for your area. This is the day in the spring that it is generally safe to start planting gardens. In Maine, it is 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 the stratification process will begin. Some seeds may not germinate until much later than 120 days, but be patient, some seeds only bloom late, or are they germinating?
  3. On or around the date you determined in step 2, fill a cup with hot water from your faucet, but do not use extremely hot water. If the hot water is steaming when it comes out of the faucet, it may be too hot. Just set 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, vermiculite, or a combination of these. The exact mix isn’t extremely important, just make sure it’s moist and not wet. I personally have had better luck with vermiculite, and it’s easier to find the seeds when planting, but go ahead and use whatever is easiest for you. Poke a few holes in the baggie with a fork to allow air to circulate. Place 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, or vermiculite is still wet, and add water if necessary. When you open the bag to check for humidity, the air in the bag is also exchanged, which helps 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 place them back in a baggie with fresh, moist sand, peat, 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 have found works best for me. Either way it works, but I’ve found I don’t have much control over the weather and it’s uncooperative at times. There have been times when my seeds were ready to plant outside, but the ground was still frozen. He couldn’t do much about it! I decided to plant the seeds in individual peat pots. You know the; the ones that swell when you pour water on it. Poke 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 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. Leave 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 to provide shade. For larger numbers, a trellis suspended over the plants on a wooden frame or cinder block is an option, but shade cloth may be a better choice. 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 tree that you can enjoy for years to come, and you can even tell everyone who comments on it that you grew it yourself!