You may already know duckweed and think of it as a nuisance. It's true it is a very invasive plant if left to grow wild and uncontrolled.  Here on our farm we have built ponds dedicated to the growing of duckweed.

The reason we have built these ponds is because we raise tilapia here in northeastern Brazil.  The duckweed plant is a great source of protein and has halved out food bill for the tilapia! For 10,000 fish, you can imagine this is quite a savings. 

If you would like to find out how to build duckweed ponds,  I have written an article on Hubpages. 

Although we use it for feeding our tilapia, there are people who feed it to chickens and other animals. It is also consumed by people in Asia. Besides using it as a feed supplement, you can also make money from growing duckweed. If you take a look at Ebay for example there will be people selling it. They are also selling it on Amazon.  When you realize how fast this plant grows you will understand that this could be a little gold mine. 

Let's look at what you will need to do to sell your plants. Firstly you will need an Ebay account. If you are like most people you already have one. On you write up about it, tout the benefits of using duckweed. Remember it isn't just about farm animals.  Think of all the people who have aquariums. Even in they grow it in a bowl on their kitchen counter for their goldfish,  they are still a potential customer of yours. 

For those who have a garden pond, they may like the idea of having duckweed either in their pond or as a feed for their fish. People who have chickens. All of these people could be your customers. Make a stunning sales page when describing the benefits of duckweed to sale on Ebay. You will need leakproof bags which you can send through the mail. Some people sell 50 plants and others sell 1/4 cup. Either way, when you see how fast this grows, it will be like a money plant. 

***One caveat here is, you can't sell plants abroad.  Check the restrictions in your country and with your postal service. Most countries do not allow this as the chance of transfering diseases and pests into a new environment is high. That said, their will be a market for it in your country.