2 Tips to Know If Your Bonsai Seeds Have Expired

  • By: Josh Koop
  • Date: February 8, 2023
  • Time to read: 6 min.
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If you’re a bonsai enthusiast, chances are you have collected many more seeds than are required to grow bonsai. You’ve probably been storing some for months, if not years. Now that you want to grow a new bonsai, you could utilize your stored bonsai seeds. But do bonsai seeds expire

Like regular seeds, bonsai seeds can expire for various reasons. Maybe they were in storage for too long, or they were stored the wrong way. There are a few ways to learn if your bonsai seeds are viable

In this article, I will tell you how to know if your bonsai seeds have expired. You should also learn how to store seeds properly so that they do not get wasted, and stay healthy for a long time. 

Tips To Know Bonsai Sees Have Expired

You can use normal seeds to grow a bonsai. However, the seeds require special techniques to grow into a bonsai. You may want to use stored bonsai seeds that were collected a long time ago.

Depending on the age and type of the tree species, properly stored bonsai seeds can stay viable for two to five years. However, these seeds can go bad and thus will not germinate.  

If you have bought bonsai seeds from a store, you will find the expiration date on the packets. Some packs may have a “sow by” date on their packets. This date shows the best time to get germination.

However, before throwing out the seeds that have passed their expiration date, you can test their viability. 

So, how do you know you can use your bonsai seeds? Fortunately, there are some simple ways to find out. Here is what you can do: 

Water Test

The easiest way to check bonsai seeds is with a simple water test. First, take a packet of bonsai seeds . Then put about ten seeds in a water container, like a bottle or glass bowl. Let the seeds soak in the water for 15 to 20 minutes. 

After that, the bad seeds will float in the water, and the viable seeds will sink into the bottom of the water container. So, you will know whether the bonsai seeds have germinated or not. 

But this test is not always accurate. Experts often ignore the water test and choose a better way to examine bonsai seeds. 

The Germination Test With Paper Towels

Even if this test takes some time, it is the most accurate way to determine the viability of your bonsai seeds. To take the test, you will need a few things. You will need a paper towel, a zip-up plastic bag, or a plastic container. 

First, take at least ten seeds of your preferred bonsai . Get a paper towel and damp it with some water. Make sure the paper towel is not dripping in water. It should be moderately damp.

Then place the bonsai seeds in a row on the paper towel. Cover them with the damp paper towel well, but not too tightly. 

Next, put the paper towel in a zip-up bag and seal the bag. You can also use a plastic container to place the paper towel and put the lid on it. This way, the towel will stay moist for a long time, which is necessary for the seed to germinate

After the seeds are sealed, keep the zip-up bag or container in a warm place. It should not get direct sunlight to avoid overheating the seeds. Also, the temperature of the storage place should not fluctuate too much.

Otherwise, the seeds will not sprout. To keep the bonsai seeds safe, store them in a high place, such as the top shelf or the top of your refrigerator.

Check the seeds for germination every day. You can moisten the paper towel if it becomes dry. Be careful not to spray too much water because it can spoil the seeds. 

Depending on the type of seed, it may take someday or several weeks for germination. In fact, some bonsai trees may even take a month to sprout. Thus, you have to be extremely patient. Generally, you should wait at least 10 to 14 days. 

If you find fewer than five seeds sprouting, you can conclude that the pack of bonsai seeds is viable for growing bonsai . If it’s less than five, you are out of luck. Hence, you have to prepare new bonsai seeds. 

Remember, the germination of the seeds depends on the type of bonsai. Besides, you have to know how to follow the damp paper towel method correctly. Thus, the time will vary. However, this method is fairly accurate in testing the quality of bonsai seeds.

Finally, plant your bonsai seeds in a pot filled with bonsai soil. Do not use regular soil to sow the seed as it will not work for them. So, learn how to prepare the soil for bonsai seeds . Place the pot at a regulated temperature and water it regularly to keep the soil moist. 

Why Bonsai Seeds May Not Germinate? 

You may have perfectly healthy seeds to grow bonsai. But when you plant the seed in the soil, you may not get the expected result. Maybe the sprouting number is low, or there is no sprouting?

Many other reasons may also cause new seeds to fail to germinate. Some of these reasons are: 

  • Storing the seeds in a place where the temperature is too cold or too hot. 
  • Not watering the seeds regularly. 
  • Over-watering causes seed rot. 
  • Using non-viable or old seeds. 
  • Not drying the seeds properly before storing.
  • The bonsai seeds are infected with insects before or after planting.
  • You planted your seeds too deep in the soil. 

So, you must avoid these issues if you want to grow your bonsai from the seeds. Always buy your bonsai seeds from a reliable source and store them in the right way. 

How to Store Bonsai Seeds For A Long Time? 

You may have some extra seeds. These seeds may be hard to get. Hence, you want to preserve them for a while for next time. To keep the seeds healthy and usable after a certain period, you need to know how to store them correctly. 

Step 1: You have to be smart about choosing the seeds right from the start. Collect only new, mature, and healthy tree seeds. After collecting the seeds, make sure they are completely dry before storing them. 

Step 2: Use air-tight jars such as glass or tin containers to store your bonsai seeds. Some use paper packs, but it is not good protection against unwanted moisture. The jar will make sure the seeds stay dry and do not come into contact with any moisture. 

Step 3: You can also put some moisture-absorbing materials like wood ash, powdered milk, dry charcoal, or pieces of newspaper with the seeds in the jar to keep them dry. 

Step 4: Put the jar in a dry and cool place so that the seeds remain viable for a long time. 

Step 5: If you have various kinds of seeds, label them. Write the name of the tree species, the date of collection, and the possible expiration date. Research the bonsai seeds to find out their expiration date. For example, maple seeds are usually viable for 12 months. 

Make sure the air-tight containers you use for the seed are clean. After sealing the lid, avoid opening the jar. Open it only when it is necessary. 


So, do bonsai seeds expire? Yes, they can expire. However, how long the seeds remain viable depends on their species and age. You can use the techniques mentioned in the article to check whether your seeds have expired. 

You must also store the seeds properly to keep them healthy for a long time.