What to know about temperature, moisture, germination

When the days begin to get longer, my mind goes in two different directions -- both of which I enjoy. I start thinking about gardening, but also fishing. Today's topic will be on gardening.

There are thousands of different kinds of plants or vegetables we can grow in our gardens. Most of them will come from some kind of seed. A few, like potatoes, will grow from the eyes of seed potatoes or from slips off sweet potatoes. But most come from seed.

This seed has different levels of quality. Seed that is poor in quality will only germinate and grow into a few healthy plants. Some seeds will germinate as high as almost 100 percent. To test germination, take a paper towel and put it on a dinner plate or something similar.

Place about 10 seeds on the paper towel. Cover it with another paper towel and dampen both towels with warm water, say 90-degree water. Place the plate where it will stay warm or around 80 degrees or so as an average.

After a few days or up to two weeks, the seeds will germinate and begin to grow. If seven of the 10 germinate, the germination percentage is 70 percent. What you do to determine percent of germination is divide the number of seeds that germinate by the total number of seeds on the plate and then take that number times 100. 7/10 x 100 = 70 percent. Many seed packages list the germination percentage.

Several things determine germination. One is the moisture. A seed needs to be damp but not wet. If a seed is either too dry or too wet, it won't germinate properly.

If you take your finger and press down on the growing medium and your finger gets wet, it is too wet. If your finger is dry, the medium is too dry. If your finger is damp, just damp, it is about right.

The second thing that determines germination is the temperature. Most all seeds have an ideal germination temperature. If the temperature is lower or higher, the percentage of germination will be lower.

Let's take green beans, for instance. An ideal germination temperature for green beans is 86 degrees. At that temperature, the highest number of beans that are viable will germinate and grow. If the temperature is higher or lower, a lower percentage of green beans will germinate. In other words, if you plant your green beans in soil that is too cool, they will not germinate like they should.

If you would stretch a piece of black plastic down your row where you are going to plant your green beans, it will effectively raise the ground temperature. After the danger of frost is over, remove the plastic and plant your green beans. The ground temperature will be higher and they should come right up.

One catalog that contains the germination temperature of all common garden varieties is Johnny's Garden Catalog. Cucumbers prefer around 86 degrees. Peas prefer from about 55 degrees up to about 80 degrees. Onions prefer from about 77 to 86 degrees. Okra likes about 84 degrees. Tomatoes like a medium temperature of around 86 degrees.

So if you want to start tomatoes in the house, the starting medium needs to be around 80 to 86 degrees. Kale prefers cooler temperatures, from 50 degrees up to 85 or so. If the ground temperature gets above that, germination falls off rapidly.

Even if you never order seeds from Johnny's, you should get their catalog. The website is johnnyseeds.com. The catalog will help you by listing the ideal germination temperature, how many seeds to order for a given length of row, the pH range the plant prefers, a list of common varieties and more. I personally order seed from Morgan County Seeds, Johnny's Seeds, Baker Creek Seeds and Pinetree Garden Seeds. Mick, my brother, also orders seeds from Seed Savers Exchange. I also buy seeds locally from garden centers.

If you have questions or comments, let me know.

Until next time.