I am often asked how we manage to germinate thousands of Japanese maple tree seeds each year because conventional wisdom says that this is considered very difficult to do.
In this article, I’ll reveal the little-known “nursery secrets” we use to ensure virtually 100% germination rates and debunk the myth that…
Germinating Japanese Maple seeds is hard to do… If you’ve read any standard text or instructions for germinating Japanese Maple seeds and you’ll usually find virtually identical advice.
Conventional wisdom holds that successful Japanese maple seed germination is hard to do, definitely something for the more advanced gardener. Conventional wisdom also says that the key to successful germination is a combination of soaking the seeds in water followed by “stratification”* (see below).
Soaking the seed is recommended because almost all the seed you buy from dealers or unknown sources (like what you’ll usually find on e-Bay) is dry. Dry seed needs to be rehydrated and then stratified* before it has any chance of germinating.
*Stratification is the scientific term used to describe the seed being allowed to experience an extended period of cold for at least 90-120 days, as if the seed had gone through a winter period after naturally falling from the tree.
Even if you’ve tried soaking and germinating dried Japanese maple seeds, you’ll know that the results are still hit or miss. People tell you it’s hard, and in fact it’s hard to get a decent level of germination from dry seeds.
Then we discover by painful practical experience that the conventional wisdom is correct. It is difficult to germinate most of the Japanese maple tree seeds that you will find for sale. To make up for any lack of success as a result of using this conventional method, you will be advised to leave your seed trays in the ground for another year in the hope that a few more seeds can germinate.
Well, good luck! You might get lucky and get a few more seedlings, but more likely you’ve provided the local mice and other critters with a tasty winter meal!
Conventional wisdom overturned!
Year after year in our nursery we achieve a germination success of 87%, 92%, even 98% in some cases. And we don’t even soak our seed!
Here is the REAL “secret” to achieving virtual 100% success in Japanese Maple tree seed germination…
… Use FRESH new season seeds! Yes, honestly, that’s the most important thing you have to do. DO NOT buy from seed dealers or online eBay sellers who do not care about the success of their seed germination. You will almost certainly get old, dry seeds buying that way.
Having bought Japanese maple tree seeds in the past from reputable seed companies and then been unable to germinate them, I decided there had to be a better way.
By chance I stumbled upon the ‘secret’ of using fresh seeds only after finding a ‘rare’ source that offers fresh seeds.
So here’s what you need to do for guaranteed germination success…
1. Get fresh new season seeds. Note: The season for fresh seeds is usually from December to March.
2. Store them in a zipper bag.
3. Store them for at least 90-100 days in the refrigerator.
4. Check the seeds from time to time and make sure they are not drying out. If necessary, add a DROP or two of water, every few weeks, so the seeds don’t dry out.
5. If (and only if) you see mold developing, and as soon as you see it, use a fungicide, very sparingly, following the manufacturer’s instructions, or apply a weak solution of bleach (1 part bleach to 9 parts water). Water)
6. At the end of the cold storage period, the seeds germinate naturally, even in the zipper bag in the refrigerator!
7. Transplant the seedlings as they germinate, planting the emerging rootstock in a seed compost. We use and recommend using a coco-based growing medium.
We grow many of our seedlings in plastic tubes. These are the same tubes used by the USDA Forest Service. In this way, we minimize the extra handling of the seedlings (thereby reducing our time/cost and the possibility of damaging the delicate seedlings when replanting).
You should also watch out for late spring frosts. Look for our YouTube video and other online articles on spring frosts and Japanese maples! Your seedlings can germinate in January – February – March and you could face a period of several weeks where new seedlings are at risk of frost damage. Your seedlings should be kept in a frost-free location, but should also have good light and air movement around them. Keep seedlings in good light or they will grow long, messy, weak stems.
It is important to remember that seedlings are hybrids. We know the ‘mama’ tree that provided the seeds…
…But we don’t know about the ‘daddy’ tree whose pollen (thanks to the bee) fertilized the flowers of the ‘mama’ tree. So just like our children, these seedlings will be similar, but NOT identical to the parents.
The seedlings should exhibit some of the characteristics of the ‘mama’ parent, but they will not be identical (a true clone). This means that we CANNOT name the seedlings with the same cultivar name as the parent. For example, Acer palmatum ‘Bloodgood’ seedlings can only be called ‘Seedlings from “Bloodgood” seed’ or Acer palmatum Atropurpureum (if left red).