Best DIY Plant Propagation Box

Find or purchase a clear plastic storage box with a lid. You can also use a glass fish aquarium with a hood if you have one on hand.

The size of the box doesn’t  matter too much, but think about what types of cuttings you will be rooting in there and how tall the  box will need to be.

The plastic storage box I use is about 16”W x 10”D x 10”H, which is perfect for most cuttings.

Add your propagation soil to the box, and spread it evenly over the bottom of the box.

The soil should be about 3-4 inches deep. It’s important to use propagation soil  (rather than potting soil) inside a propagation box to ensure success.  

Add water to wet down the propagation soil. Keep the soil moist but not soggy, and never allow it to dry out completely.

If you added too much water to your propagation box, you  can simply leave the lid off the box for a day or two to allow the excess water to evaporate.

You can root just about any type of plant cutting in this propagation box, so I encourage you to experiment!

Whenever I trim a plant or a piece  breaks off, I’ll put the cutting into my propagation box.

For best results, dip the cut end of your plant  cutting into rooting hormone before sticking it into the propagation soil.

Make a hole in the soil with  your finger and place the cutting into the hole so the rooting hormone doesn’t rub off.

Lightly pack the soil around the stem of the cutting to ensure the medium is touching the cutting.

At least one leaf node should be below the soil line.

Make sure that none of the leaves are below the soil, and pinch  off any leaves that are laying on the surface of the soil. 

Put the lid on your propagation box. If the lid on the storage container is airtight, poke some holes in the lid or prop it open slightly to allow air to circulate in the box.

Air circulation helps prevent mildew growth in the propagation box. I like to use an electric drill with a  small-medium sized drill bit to drill holes in plastic lids because some types of plastic will crack if you try  to make holes with a hammer and a nail.

Drill the holes 2-3 inches apart on the lid. 

Place your propagation box in an area near a sunny window inside the house. If you don’t have a sunny room to put it in, place a plant grow light above  the top of the box. It’s best to keep your propagation box inside the house to keep it protected from  wind, rain, bugs and too much sun. But, if you must put it outside, it should be kept in the shade and  protected from rain so it doesn’t get overwatered. Inside or out, always keep your propagation box  out of direct sunlight.  

Use bottom heat to help speed up the rooting process. You can add bottom heat by placing your propagation box on a heat mat (the same one you use  for your seedling trays). During the winter, you can place your propagation box on or near a heat  vent (be careful if it’s near a vent, because the dry air from the heat vent will cause the soil in your  propagation box to dry out faster). 

Soft stem cuttings  will root in about three weeks (some will root in as little as few days), and hardwood cuttings will take  about 8-10 weeks. 

You’ll also want to monitor the humidity level inside the box, and the moisture level of the  propagation soil. The soil should never be soggy or completely dried out, it’s best to keep the soil  consistently moist. To water your propagation box, use a gentle spray from the kitchen sink sprayer or  a plant mister; you don’t want to disturb the propagation soil once your cuttings are in the box.