VOA慢速英语2021--Growing Trees From Seeds（在线收听）

Maple and oak trees with branches full of seeds at the end of summer got American plant expert Lee Reich thinking about how trees grow.

He remembers how, a few years ago, he decided to drop an apple seed into some soil he had placed in a small container. Reich imagined his small seed would turn into a beautiful apple tree. But, it didn't work out. The seed germinated and started growing. But then, it stopped growing when it was just 10 centimeters tall.

How come?

Reich said most seeds that come from colder parts of the world need special treatment before they will grow. He found out that he was lucky his seed grew at all!

Reich now knows how to grow a tree from seeds. When those seeds fall from the branches of tall trees, they cannot start growing right away. Reich noted that the young trees would die during the cold winter if they start growing immediately.

So, most seeds know how to stay asleep during the winter until warmer weather comes. That is when they can grow well. But, if you do not want to wait all winter for your seeds to grow, Reich has some suggestions.

‘Fool the seed'

Reich said you can "fool the seed" into starting to grow.

The way to do this is by placing the seeds into plastic bags filled with potting soil that is a little wet. Then put the bags into a cool place like a garage or refrigerator. The process is known as "stratification."

It is important to keep the seeds cool, but not too cold, for a few months. The temperature needs to be above freezing but below 10 degrees Celsius.

Reich said you might have a little more work to do before stratification, depending on what kind of seed you are growing.

Harder seeds first need to be softened to let water get in. Such hard seeds come from redbud, juniper and hornbeam trees.

To get water inside the seed, you need to nick them with a small, sharp object. The other way to soften a seed's hard shell is to put them in soil and leave them in a warm room for two or three months. Then you can begin stratification.

Once the seeds are stratified and conditions are right, they will start to grow roots. For sugar maple trees it might take three months. For apple seeds, it might take only two months.

But Reich shares a warning. Don't forget about your stratifying seeds! One week, he said, they could be asleep. The next week, they could have fat, white roots. Once your seeds start to grow roots, you can put them in a container, or pot. Or, if you are not ready, keep them somewhere cool until you are ready to plant them outdoors.

Reich noted that some people may wonder what the point is of all this trouble when you can just buy a small tree at a garden center.

"You're a gardener, you like to grow plants," he explained.

Reich also said how satisfying it is to look up after many years at a tall tree that you once started from just a seed.

Words in This Story

branch –n. a part of a tree that grows out from the main body, or trunk

gardening –n. the act of taking care of the plants on an area of ground (v. garden)

germinate– v. to begin to grow (a seed)

pot– v. to plant something in a pot

garage– n. a building or part of a building where a car is kept

refrigerator – n. a device or room that is used to keep things (such as food and drinks) cold

stratification – n. the act of arranging something in layers

nick– v. to cut or damage a small part of the surface of something