Hydroponic Seed Starting 101: A Primer For Beginners

Shannon McKee | July 10, 2017

Takeaway: Starting your seeds hydroponically has many benefits, but many people are unsure how to go about it. Shannon McKee gives us a primer on the basics of starting your own seeds to expand on what you’re currently growing.

Many people skip starting their own seeds because of the time and effort to get them started, but there are some great reasons to start your own seeds hydroponically. It’s so much easier to just go to the store to pick up some seedlings to pop into your system and get growing, right? Well, store-bought seedlings do have some downsides that can be avoided if you start your own.

The first is that you’re limited to what you can grow in your system. You have to choose from the options available at the store. However, if you start your own seeds, you can grow anything. This means you can grow your favorite heirlooms or even rare plants that aren’t found at many nurseries.

Adding seeds to your hydroponic system means that they won’t go through any trauma or root damage from being transplanted into your system. This process may also introduce diseases or bugs into your hydroponic system from the store.

Also, you get the satisfaction of growing a plant from a tiny seed rather than just picking up a seedling. Plus, a packet of seeds can grow a number of plants for just a few bucks, whereas the cost of only one seedling can be the same amount.

Seeds are also more cost-effective than buying one or two seedlings in the long run, as you can save some for the following year. The germination rate can decrease over time, but often, you can still get quite a few to sprout over the years until you have to buy your next seed packet.

What You Need to Start Seeds in a Hydroponic System

The first time you start your own seeds for your hydroponic system may be a bit more expensive at the beginning because you need to buy more materials than in future years. Seeds need water, light, oxygen, and heat to grow. You really don’t need anything too special to grow your own seeds.

You can use a grow tray with a dome for your own miniature greenhouse to create an ideal environment. If you’ll be growing your seeds in an area that is cooler, you may want to invest in a heating mat that goes underneath the grow tray to keep it warm as this is a necessary condition for sprouting to occur. Light is good to have as well as this will help your seeds sprout.

Inside of your grow tray, it can be beneficial to use a pot that works for your seeds and their future as seedlings in your hydroponic set-up. You’ll want to use starter cubes, such as those made of stonewool (rockwool). The key here is to use something that can withstand being immersed in water without dissolving, as it could clog up your system after transplanting.

Step by Step Instructions for Sprouting Seeds in a Hydroponic System

• The first thing that you’ll want to do is to soak your starter cubes in clean water for about an hour. After they’ve been given a chance to soak, put a few seeds into the cube’s hole. You’ll want to add several just in case you have some seeds that don’t germinate. Once they sprout, you can thin out the weaker plants to allow the strongest to grow.

• Prepare your grow tray with about an inch of clean water or nutrient solution that is at half strength. Arrange the light source and heating mat as needed. You can keep the lid on to keep the heat and moisture in the tray.

• Put these planted cubes into the grow tray and add water or the half strength nutrient solution as the level goes down in the grow tray.

• After about four days, you’ll start to see some sprouts emerging.

Some people prefer to use a Ziploc bag, rather than a grow tray, when trying to get the seeds to germinate as it functions like a greenhouse. Seal the bag with a little bit of air and put it in a dark place for about four days to get the seeds sprouted. Then, you can put the starter cubes with sprouted seeds into the grow tray.

Step by Step Instructions on Transplanting

Keep your tiny seedlings growing strong with your hydroponic nutrient solution. Once they’ve gotten bigger, you don’t have to make the nutrient solution half strength.

You’ll start to see the seedlings’ roots coming out of the bottom of the cube, and this is the sign you’ve been waiting for, as it means you can start transplanting. This can take about two to four weeks depending on what plants you’re growing.

Clear up a spot in your hydroponic system’s growing media for the seedling – cube and all. Gently transfer the starter cube into your growing media, and cover it gently.

Give the root system a chance to naturally seek out the water and nutrients in your system by top watering it for a few days to give it a chance to grow the root system.

Voila! You grew your own seedlings into a strong plant for your hydroponic system. Depending on the type of plant, you’ll be able to get your first harvest about four to eight weeks from the time you transplanted your seedlings.

Cut out the dependency of only being able to grow the types of plants that are available as seedlings at your favorite gardening store. Take a little extra time to nurture your seeds so that they become strong seedlings ready to transplant into your system. You’ll be able to take pride in your efforts with how healthy your plants are and your overall system’s health.