DIY ProjectsPropagation & Seed Starting

How to Build a Simple Homemade Plant Propagation System

This homemade plant propagation system is extremely easy to build at home and lets you root cuttings of all kinds of plants. Its fun to see how many kinds of plants you can root using this simple technique. And since they don’t cost you anything, that makes it even better.

The very first thing that you need to purchase is a very inexpensive fish aquarium. The size doesn’t matter because you are going to build the rest of your homemade plant propagation system around the aquarium. Don’t make it too large or it will be too heavy to lift and put into place. If you want to root a lot of cuttings, you’re better building more than one of these plant propagation systems. I picked up an aquarium at the discount pet store for less than $10.00.

Once you have the fish aquarium you need to measure and obtain the outside dimensions of the top of the aquarium. Then, using 1″ by 4″ lumber, construct a box or a flat with an open bottom like the one the above photo. Make the inside of your flat one inch larger than the aquarium in both directions.

In other words, if you measure across the top of your aquarium and find that the width is 9½”, make the width of your flat 10½” on the inside. If the length is 20″, make the length of your flat 21″ on the inside.

When your flat is complete you should be able to turn the aquarium upside down and place it inside the flat and have approximately ½” of space on all four sides.

Notice how simple the flat is to build? All you need is four pieces of wood to make the fours sides and then three pieces across the bottom. Notice that there is small gap on each end of the bottom and two larger gaps in the middle. The size of these gaps doesn’t really matter, you just want to have openings so water can drain through.

It’s difficult to see in the photo but if you look closely, you can see that we have lined the bottom of the flat with a piece of rigid hardware cloth (screen). Make sure the hardware cloth you use is quite rigid, so it doesn’t sag below the gaps on the bottom when the flat is full of potting soil. If you go to a full-service hardware store they’ll have what you need.

Now it’s time to paint the homemade plant propagation system. From now on the aquarium will be used upside down, so what was intended to be the bottom we are now using as the top. Confusing I know, but the photos should help.

Notice how masking tape has been applied to the top of the aquarium? You’ll see in the next photo that a strip of masking tape was applied, a one-inch gap was left and then another piece of tape was applied and so on. A one-inch piece of masking tape was also applied all the way around the aquarium, about one inch from the top.

Once it is taped spray paint the entire aquarium with white paint. White paint reflects the rays from the sun to keep our system from getting too hot. Apply the tape before spray painting, then as soon as you are done painting, even before the paint has a chance to dry, pull the tape off exposing strips of clear glass, or plastic.

These clear strips allow a small amount of sunlight to enter our plant propagation system while the painted areas block out most of the sun’s rays. This gives the cuttings the amount of sunlight they need but keeps it from getting to hot inside. Make sure the paint you buy adheres to glass or plastic without special preparation.

Now it is time to fill the flat with potting soil. For rooting cuttings buy a bag of potting soil that contains as little nitrogen as possible. When you are trying to root cuttings you do not want to encourage top growth, so use just a good blend of potting soil that is light and contains some Perlite for drainage. If you don’t think the soil you purchased has enough, or any Perlite at all, you can always add some.

When rooting cuttings you want the soil to be moist but not wet and soggy. It’s kind of like baking a cake. Nobody likes a dry cake, but most people love a moist cake. But nobody would care to eat a wet or soggy cake. Your cuttings like their soil exactly the same way you like your cake!

Fill the flat completely with potting soil, press down on the soil, packing the center, the corners, and the edges. You want the soil to be firmly packed into the flat.

Now it’s time to start filling your flat with cuttings. You might have to use something like a Philips screwdriver to poke holes in the potting soil so your cuttings slide in easily. As you stick the cuttings gently pack the soil around each cutting, so they stand upright and any air pockets around the cuttings are pressed out.

Make sure you dip your cuttings in a rooting compound before you stick them. A rooting compound is not magic, and cuttings will root without it, but it greatly increases your success rate. The brand of rooting compound you use doesn’t matter. Both liquids and powder rooting compounds have been proven to work equally well. But the strength of the rooting compound you use does vary depending on what time of year you are doing your cuttings.

If you are sticking cuttings in the late spring you should only be taking softwood cuttings, and the rooting compound should be on the weaker side. If you are doing hardwood cuttings in the fall or winter, the rooting compound should be stronger.

With powder rooting compounds you have to buy different strengths for different times of the year. But with most liquids you have to mix them with water, and you adjust the strength that you need by adding more or less of the concentrate to the water. Brand name doesn’t matter; they all do the same thing. If it sounds complicated don’t get nervous. The instructions are right on the bottle.

Stick all of your cuttings at once so they don’t dry out as you are filling the flat. Once the flat is full, gently water the cuttings in, soaking the soil thoroughly. This also helps to eliminate any air pockets around the cuttings. You can stick the cuttings in the flat as close together as one inch. They really don’t need much room at all to root.

Once you have the flat full of cuttings, just place the aquarium over top of the flat, resting it on the potting soil in the flat. As you stick your cuttings you want to keep them at least ½” from the edge of the flat so there is room for the aquarium to rest on the potting soil, just inside of the flat.

The only thing left for you to do is move your homemade plant propagation system to an area that is partially shaded and make sure the soil in the flat doesn’t dry out. You’ll be able to tell how moist the soil is just by the amount of condensation on the inside of the aquarium. Check the soil for moisture every day until you can gauge how often it needs additional water.

You’ll be amazed at the different kinds of plants that you can root using this system, and you’ll be amazed at the different things that you can be doing at different times of the year.

You can do hardwood cuttings all winter long, and once you have your flat filled with hardwood cuttings you can move it outside, even if you live in a cold climate. Hardwood cuttings are tough, and they don’t mind the cold and freezing weather at all. Just make sure the medium remains moist all winter.

Mike McGroarty is the owner of McGroarty Enterprises and the author of several books. You can visit his website at and read his blog at

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