• PO Box 25079, Tempe, AZ 85285 USA

Growing Duckweed

Duckweed is easy to grow and is a nutritious snack for water fowl, poultry, and fish

We really appreciate what duckweed contributes to the Garden Pool. We dedicate more surface area of growing duckweed than to any other plant we grow. The tiny floating plant adds nutrition to the diets of our fish and hens while purifying the water. It really is an amazing plant. Despite our love for the plant, most of the literature you will find online about duckweed is how to eradicate it. Most folks consider it a bothersome invasive species that turns nice lakes in to something that looks like a swamp. Here are some tips from the Garden Pool Team to grow duckweed, successfully.

The deep end of our pool is full of duckweed.

  1. Duckweed prefers slow moving water however, you will notice fastest growth with areas of agitation. Slight agitation, such as where an outlet flows, seems to increase the asexual reproductive process. The duckweed divide quicker.
  2. Grow in several places. You will find the best micro-climate for production this way. Also, if one spot fails, you have several others producing.
  3. Do not grow in the same area as you are raising your fish. They’ll eat your crop.
  4. Surface Area! The more you have the more you will get. Duckweed needs only a few inches of water, but takes as much space to spread as possible.
  5. Duckweed grows faster in warmer weather. If you want faster yields, make sure your water temperature is over 70°F.
  6. If your duckweed is turning white, something is wrong. The duckweed is dying.
  7. Don’t forget nutrients! Duckweed needs more than water and sunlight to grow. We use the tilapia waste water to grow our duckweed, but you can use other nutrients. Compost teas or organic hydroponic nutrients also do well.
  8. Not all duckweeds are equal. We have experimented with several different species of lemna and have found that lemna minor is our favorite duckweed for production.
  9. Duckweed has the smallest flower in the world, but we have never seen it. Don’t worry about pollination as means of reproduction. The plant grows and divides asexually, much like a single-celled organism does. Don’t worry about finding tiny bees.
  10. Duckweed can grow thick! When production is highest, duckweed can grow several inches thick. We have had our pond area full before and it looked like a lawn.
  11. Don’t forget to add oxygen. If you place duckweed in a pool without aeration the water will eventually go anaerobic. Without oxygen, nothing will grow.
  12. If you grow in an aquarium you may grow more algae than duckweed. Duckweed naturally limits the growth of algae because duckweed floats and gets the light before the algae. In aquariums this does not happen.

How to Grow Duckweed Video

Class: Getting Started in Aquaponics
Recorded LIVE
When: June 29th, 2013
Where: The Garden Pool in Mesa, AZ
Length: 33 minutes
How to grow duckweed was recorded live in a classroom setting. To be a part of our classes in person, join our meetup group.