The process of seed germination is the process by which a plant grows from a single seed. Has it ever happened that you sowed a seed, but nothing grew from it? The causes of poor seed germination can be the seeds’ age, inadequate storage, damage, and numerous mistakes during the sowing itself.
If you want to avoid something like that happening again, follow our tips on testing, improving, and accelerating the germination of vegetable seeds.
Learn how to:
- how to do a seed germination test
- how to improve and speed up seed germination with the help of towels or coffee filters
- with which types of seeds can you improve germination
Why Is Testing Seeds Germination Recommended?
If you have seeds for which you are unsure how old they are or have not been kept in a dry and dark place, it is always better to test their germination before sowing. The germination test will show the percentage of seed germination, i.e., how many seeds will sprout a plant on average. Namely, if you sow a bad seed and it does not sprout, you will lose valuable time because you will have to start the process all over again. Of course, you can always buy ready-made seedlings, but if you want to grow vegetables from your own seedlings, it is better to be sure that the seeds will germinate.
For the seed germination test, you will need the following:
- A dozen vegetable seeds
- Coffee filter or absorbent towel
- Transparent plastic container (I usually use plastic packaging for food)
- Chemical/felt pen
Seed Germination Test Methods
Step 1: Take half of a coffee filter or paper towel. The coffee filter has denser fibers, so the seed’s root will not get tangled in it, as can be the case with paper towels. But paper towels absorb more water, so I prefer to use them.
Step 2: Cut a paper towel or coffee filter to the size of a transparent plastic box and place it on the bottom. Drop a few drops of water on it. Be careful not to add too much water; the towel/filter must be moist but not wet. Wait before adding more water, as a few drops will spread all over the towel/filter.
Step 3: Randomly select a dozen seeds from the seed bag you want to test and place them evenly on the towel/filter about half a centimeter apart.
Step 4: Lay another napkin or filter of the same dimensions on top of it all. Wait to see if the top towel also gets wet by absorbing the water from the bottom towel. If the top napkin remains dry, put a few drops of water on it and cover the box.
Step 5: Write down the type of seed and the day you put it to germinate on the box.
Step 6: Put the plastic box in a warm place where there is light, but never on a radiator because you risk the seeds being cooked or dried out. I usually put it above the fridge because it generates minimal heat from the outside, which is enough for the seeds to germinate.
Step 7: On the instructions for sowing on the bag, read the germination time for the vegetable you put to germinate. Monitor the seeds daily to ensure they do not dry out and, if necessary, add a little water. When the germination period has passed, see how many seeds have sprouted. If, for example, 5 seeds sprouted, the germination rate of your seeds is 50%. If the germination rate is less than that, don’t even bother to sow the seeds outdoors.
Direct sowing of seeds in the ground reduces their germination. This can happen because:
- the seed does not get enough water
- the seed gets too much water and rots
- the air remains between the soil and the seed, so the developing root cannot draw water from the soil
- the temperature below the ground is not high enough for the seeds to germinate
For these reasons, in addition to testing germination, you can also use the towel or coffee filter trick to speed up and improve seed germination.
Repeat the procedure described above to test seeds’ germination, but choose a larger plastic or several smaller ones so that you can put more seeds in them. Always plant more seeds than you need a seedling because not all seeds will ever germinate.
It would be best to use one plastic container for each type of vegetable so that you know which seeds have germinated. Sometimes it happens to me that I put the seeds of two different types of the same vegetable or the seeds of two similar vegetables in the same container. Then I make sure to make a more significant gap on the paper between the two types and write which type it is on the cover above each one. In the case in the picture, there was no need for spacing because tomato seeds are very different from cucumber seeds.
The Process of Seed Germination for Sowing in the Ground
Step 8: Repeat steps 1-7 and monitor the situation. If the paper in the box dries out, moisten it further.
Step 9: When you notice that a root has developed from the seed and/or leave it in the container for a maximum of one or two more days so that the root grows a little stronger.
Step 10: When the seed has germinated, and the root is at least as long as the seed, carefully separate each seed from the paper, being careful not to break the sprout or root. You can also do this with tweezers. If the root is entangled in the paper, cut off all the paper around the seed and place it in the soil together with the paper.
Step 11: Wet the container with soil with water. Make holes in the ground about half a centimeter deep; if it is a larger seed such as beans, you can make them deeper and place the germinated seeds in them so that the root faces down.
Step 12: Cover the seeds with a thin layer of soil and press down so that there is no air left around the seeds. Continue to care for the sown seed as if you had sown it directly into the ground.
Make Seeds Germinate Faster With the Help of a Wet Towel
All vegetable and flower seeds can be germinated in a paper towel or coffee filter. This method benefits species with a long germination period, such as peppers.
Certain types of seeds that need a lot of heat to germinate (such as chili peppers) are stubborn, taking up to three weeks to germinate. In addition, they also need the right conditions for sprouting: an optimal balance of heat, moisture, and weather conditions.
In most cases, the seed usually lacks one or two of these conditions, which slows down germination. The described method speeds up the process by providing optimal conditions for the seeds with minimal effort on your part.
Tomato seeds will germinate quickly in a paper towel or coffee filter, as will cucumber, squash, cantaloupe, and watermelon seeds.
The method also works for kale, cabbage, broccoli, and turnips, but these seeds germinate quickly anyway, so you can sow them directly in the ground.
The same can be said for flower seeds. Although you can put them to germinate on paper first, germination speed is not as crucial for flowers as it is for vegetable seeds.