HydroponicsPropagation & Seed Starting

4 Grow Media Tips to Make Hydroponics Simple

To make hydroponic gardening easy there are some useful tips when it comes to using growing media. From just getting started and propagating unrooted cuttings, to germinating seeds and transplanting, if a grower follows these tips hydroponic growing can be very easy.

Getting Started

The first step is to sterilize all your tools, trays and equipment – anything you expect to come into contact with seedlings or cuttings – in order to reduce the risk of disease. Once you’re done cleaning, separate the hydroponic media sheets into strips or individual cells, as crop spacing or your hydroponics system requires. Be sure to space cubes enough to allow proper air circulation and light levels for the specific plant you’re growing.

Next, you should fully saturate the media with water, making sure to drain off and dispose of any excess. After sowing your seeds, be sure to keep the media moist and be sure to use to a clean, new sheet media each time you start a new crop in order to maintain a disease-free environment.

Unrooted Cutting Propagation

Prior to sticking unrooted cuttings, gardeners should fully saturate the media with fresh water. Once that’s done, place cuttings in the media with only enough pressure to seat the cuttings at the bottom of the hole. This is typically between a half and three-quarters of the full depth of the cube.

Since cuttings have no roots, you must maintain high humidity levels with a humidity dome, spray bottle or mist system. Be sure to keep the media moist, too. Once you begin to see initial root development, feel free to reduce humidity levels. For the best performance, gardeners should maintain a consistent bottom heat of 75-80 degrees F, depending on crop requirements. Read this article for more information on how to use bottom heat to propagate cuttings. Then, after plant roots begin to develop, you can begin a more formal fertilization program – adjusting temperature and light levels according to the needs of your specific plant.

Seed Germination

Prior to sowing, make sure you fully saturate the growing media with fresh water. Next, place your pelleted or raw seeds in the cube. There is no need to cover the seed with any other media. However, you should always keep the media moist during germination. In fact, it is a good idea to maintain a water level of approximately ¼” in the tray, lowering the level as the plant roots develop.

For uniform growing results, maintain a consistent bottom heat level of from 75-80 degrees F. Using a humidity dome will aid in germination, but you’ll need to remove the dome as soon as roots begin developing to help reduce the risk of disease. Once germination occurs and the roots start sprouting, you can begin your fertilization program to enhance plant growth. Again, you’ll need to adjust the temperature and lighting according to your specific plant’s needs.


Depending on the crop and the hydroponics system you use, you may need to transplant your seedlings or cuttings. If that’s the case, you’ll want to thoroughly water media prior to transplanting into another media. To determine whether your seedlings or cuttings are ready to transplant, simply measure how far the roots protrude from the media. When roots stick out ¼” to ½” from the media, it’s time to transplant. You don’t need to remove your plants from the media when transplanting, just transplant the media along with the plant into its new “home”. Eliminating the need to remove the plantlet from the media will prevent root shock or damage and continue to promote healthy plant growth. At this point, you should continue with your regular fertilization program, maintaining the proper temperature and light levels for your specific plant type.

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