I am often asked how we manage to germinate thousands of Japanese maple seeds each year because conventional wisdom says that this is considered very difficult to do.
In this article I will reveal to you the little known “nursery secrets” that we use to guarantee virtually 100% germination rates and disprove 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, you will usually find practically identical advice.
Conventional wisdom holds that successfully germinating Japanese maple seeds is difficult 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 seeds you buy from merchants or from unknown sources (such as those you will normally find at e-Bay) are dry. Dried seed must be rehydrated and then stratified * before it has any chance to germinate.
* Stratification is the scientific term used to describe allowing the seed 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 sprouting dried Japanese maple seeds, you know that the results are still unpredictable. People tell you that it is difficult and in fact difficult to get a decent level of germination from dried seeds.
So we find out from painful practical experience that conventional wisdom is correct. It is difficult to germinate most of the Japanese maple seed 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 will germinate.
Well, good luck! You may be lucky enough to get a few more seedlings, but chances are 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 didn’t even soak our seed!
Here’s the REAL “secret” to virtually 100% successful Japanese maple seed germination …
… Use FRESH new season seeds! Yes, honestly, that’s the most important thing to do. DO NOT buy from seed merchants or eBay online sellers who do not care about the success of their seed germination. You will almost certainly acquire old, dry seeds by purchasing that way.
Having bought Japanese maple tree seeds in the past from reputable seed companies and then failed to germinate them, I decided there had to be a better way.
By chance I stumbled upon the ‘secret’ of using fresh seed only after finding a ‘rare’ source that offers fresh seed.
So here’s what you need to do to ensure germination success …
1. Get fresh new season seeds. Note: The fresh seed season is usually from December to March.
2. Store in a zippered bag.
3. Store them for at least 90-100 days in the refrigerator.
4. Observe the seeds from time to time and make sure they do not dry 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 of Water).
6. At the end of the cold storage period, the seeds germinate naturally, even in the resealable bag in the fridge!
7. Transplant the seedlings as they germinate, planting the emerging rootlets in seed compost. We use and recommend using a growing medium based on coir (coconut).
We grow many of our seedlings in plastic tubes. These are the same tubes that the USDA Forest Service uses. In this way we minimize the additional handling of the seedlings (thus reducing our time / cost and the possibility of damaging the delicate seedlings when replanting).
You should also be careful of late spring frosts. Look for our YouTube video and additional articles online on spring frosts and Japanese maples! Your seedlings can germinate in January – February – March and you could face a period of several weeks in which new seedlings are at risk of frost damage. Your seedlings should be kept frost-free, but they should also have good light and air movement around them. Keep the seedlings in good light or they will grow long, messy and weak stems.
It is important to remember that seedlings are hybrids. We know the ‘mama’ tree that provided the seeds …
… But we do not know the tree ‘papa’ whose pollen (thanks to the bee) fertilized the flowers of the tree ‘mama’. 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 parent ‘mama’, 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 ‘Bloodgood’ seedlings or Acer palmatum Atropurpureum (if they have red leaves).