How to Use Hydroponic Grow Sponges

This may be a novel idea to some of you, but hydroponic sponges are great alternatives to replace soil when growing plants. We all know that soil can be a hassle when they spill and mess up our gardening spaces. Furthermore, if you’re a hydroponic grower, sponges are a much more affordable alternative to Rockwool cubes, which are costly. 

Sponges are a convenient alternative since they are compact and light. Additionally, sponges can are excellent growing mediums as they help to reduce root damage during the transfer of seedlings. Use any regular sponge, or purchase one from the supermarket near your house.

This idea may be novel to some, but do feel free to try it out as an experiment. This activity only needs a sponge, a tray or container, seeds, and water and sunlight. Expect to see a pleasant surprise when your seeds begin sprouting and growing into mature plants. 

Preparing the sponge

When choosing your hydroponic sponge, you may opt for sea sponges rather than regular kitchen sponges from the supermarket. They can serve as a natural piece of decor in your home or garden. 

Before you begin planting seeds in your sponge, check that they are clean and have not been in any contact with chemicals like detergent or antibacterial solutions. New sponges are recommended – try to avoid using reused sponges as they might be contaminated with dirt or mold. 

Prepare the hydroponic sponge by washing it in some diluted bleach. Then wash it thoroughly in clean water. 

Place the sponge in any waterproof container you like. Choose a container that is close to the size of the sponge. This will be perfect since it can prevent the spillage of water. You may also cut the sponge to fit the container’s shape if you want. Next, pour a small amount of water into the bottom of the container, although it should fill no more than half an inch to its height. 

Planting your seeds

If you’re unsure of what type of plants to grow, here are some suggestions – lettuce, watercress, carrots, tomatoes, watercress, radish, and herbs such as chives. Apart from vegetables, you may also opt for flowers like marigolds and nasturtiums. For the best results, do some research on seeds that can germinate rapidly, and for plants that can grow in the existing climate of the place. 

Sprinkle the seeds over the sponge, and pat them into the sponge. Try to leave some space between each seed, if possible. If the seeds are too big, press the seeds and make sure they are securely placed into the sponge holes. An alternative method would be to cut a large hole in the sponge, where you will place your seed to grow. 

Using plastic cling wrap, cover the container, and poke holes into the plastic with a small stick or pencil. This step is important to prevent the excessive accumulation of moisture, and to provide air circulation for your seeds. Next, find a warm place in your home or garden to place the sponge, and wait a few days for the seeds to germinate. Note that warmth is essential in ensuring that seeds germinate. 

The number of days before germination occurs varies. Lettuce seeds usually take around two to seven days, depending on the existing temperature. Some herbs, like chives, usually take much longer, from two to three weeks to sprout. The warmer the temperature, the faster the seeds will sprout.  

Growing the seeds

As you wait for the seeds to sprout, you may lift the cling wrap and inspect your sponge for signs of mold or drying. Add water to the sponge using a spray mist bottle, giving only a few sprays to ensure it is not excessively soaked. Remember that overwatering should be avoided, as this can cause mold growth or rotting. 

Once the seeds have grown into seedlings, place the sponge garden in any spot that receives plenty of sunlight. This can be on your countertop or windowsill, or any place in your outdoor garden. If there is little sunlight where you live, you may place your mini garden under a fluorescent light instead. Give the seedlings as much light as possible, as plants may grow poorly in shady areas. 

Enjoy your harvest

Once the seedlings have matured into plants, wait for them to grow to heights of three to four inches. Once they have reached this stage, you may harvest them. Simply bury the sponge within some soil, or transfer it into a hydroponic system. 

Some final tips: to produce fuller, leafy plants, especially for herbs – pick the leaves from the growing tip – this allows new leaves to grow along the stem. 

Additionally, if you are doing this project during the spring season, it is advised to keep the mini garden indoors. Even though temperatures are warmer in spring, a late spring frost might cause germinated seeds to die. 

Once grown, transfer the mature plants into bigger pots or garden boxes. Once done, you will have your first batch of vegetables or flowers grown from sponges! To grow another batch, simply wash and reuse the sponges again before planting a new group of seeds. 

Planting seeds in sponges can be a simple and fun family activity, especially during the winter when it can be too cold to do gardening. Hydroponic sponges allow you to monitor the progress of plant growth, and you can also see the roots developing inside the sponge. Children would love to take on this little project, and you can carry this out as a science experiment to teach them about plant growth. 

Furthermore, this method is great for those who don’t own gardens or who live in small spaces, as the sponge is capable of growing many seedlings. Should some seeds fail to sprout, you can simply reuse the sponges, making this a convenient and inexpensive way to try nurturing plants you’ve never grown before. 

If you decide to take on this activity, document the process with photos. If you are successful, share this unique growing technique with other green thumbs and encourage them to try it out as well!


Share on facebook
Share on twitter
Share on pinterest
Share on linkedin