Herb Propagator using Fish Tank Air Pump
Problem addressed/functional need
Propagating your own herbs can save you a lot of money in your own fields and make you money at market. But soaking cuttings to develop roots requires you to change the water twice a day, making it a big consumer of time and attention with spotty results.
The Fish Tank Air Pump Herb Propagator is a simple set-up using a white plastic 'fish tub' (often a waste product from seafood shipping to restaurants), a fish tank air pump, and water. Holes are drilled in the lid of the fish tub, where the cuttings can slip through to meet the water level in the tub. The air pump provides a steady supply of fresh oxygen to the roots of the plants, meaning less need to change the water and more consistent oxygen exposure.
Bill of materials and Sourcing
-4" deep 'fish tub' free from a friendly restaurant
-1/4" drill bit and drill
-Fish Tank Air Pump Like this one from Petco, $10.39
Construction/how to build
Start by drilling 1/4" holes in the lid of the fish tub, spaced about one inch on each side. Take your herb cuttings and remove all leaf matter except the very top set of leaves-- this reduces the amount of transpiration and ensures your cuttings will be less stressed. Stick cutting stems through the top of the lid so the stems can hang down into the fish tub. The leaf matter at the top of the cutting will prevent the cutting from falling into the water. Fill the fish tub with water, place air stones from air pump in water, then affix the lid. Plug in the air pump and observe daily to make sure stems are below water level and to check if water needs changing. You should need to change the water about once per week. Use only non-chlorinated water. Depending on the plant being propagated, you should see root growth within 1-3 weeks.
After roots are well developed, the cuttings will have to be put in greenhouse pots with potting mix to establish them in growing medium.