Hydroponic Seeds – 5 Helpful Hints to Get You Started

Cherry Tomatoes

Hydroponic Seeds

Gardening Seeds – Hydroponic Seeds.  What’s the Difference?   None really – it’s all about what seed will grow best in a hydroponic system.

Starting seeds can be a challenge for any gardener, even if they do sprout, seedlings can wilt shortly after being sprouted.   This can be very frustrating and giving you “why did I waste my time feeling”.

An advantage of indoor hydroponics, you are not limited to any season.   Imagine being able to grow year-round – fresh lettuce or herbs at your beckoned call.

Another challenge is that you can’t just buy any seed, hoping that it will work in your hydroponic system.   If you do, you are going to be disappointed.   For instance, for some reason when I have planted spinach in my outdoor units they grow in abundance – when I try indoors it hasn’t worked at all.  (There is always hope).

In addition to identifying the right seeds to sprout for your hydroponic systems – you need optimal conditions from the start.   The correct starter medium, moisture, and light.   Let’s discuss first start with a growing medium then move on to moisture/nutrient and light, then finally choosing the correct seed.  5 Helpful Tips to Get Your Seeds Sprouted and Started

Determine the Right Sprouting Medium

There are several types of medium you can use – some of the most commonly found mediums are:

  • Rockwool is what it sounds like – it is a lightweight hydroponic substrate made from spinning molten basaltic rock into fibers, which are then formed into cubes, blocks, growing slabs and etc.  While it does not contain asbestos, the problem with Rockwool if it is a large block it can contain a lot of dust and fibers.   Not good for the old lungs. For hydroponics, it is commonly found in small cubes (which is safer to use) and is a good inorganic medium for starting plants.
  • Grow Rock
    is a Lightweight Expanded Clay Aggregate (L.E.C.A.), Commonly known as Expanded Clay Pebbles.   It is a type of clay that is super-fired to create a porous texture. It’s heavy enough to provide secure support for your plant’s but still lightweight. Grow rocks are a non-degradable, sterile growing medium that holds moisture, has a neutral pH, and will pick up the nutrient solution to the root systems of your plants. Hydroponic grow media is reusable, it can be cleaned, sterilized, then reused again. Although on a large scale, cleaning and sterilizing large amounts of grow rocks can be quite time-consuming. Grow rock is one of the most popular growing mediums used for hydroponics, and just about every store selling hydroponics supplies carries it.
  • Vermiculite – t’s a mineral that is heated until it expands into pebbles. It retains more water than perlite and can wick (draw) water and nutrients upwards. Often used in combination with other types of media to create a highly customized media for specific hydroponic applications.
  • Perlite – was one of the first reliable hydroponic growing mediums available to the horticulture market. You have seen it in the form of hard white bits in potting soil, but perlite can be used by itself in many hydroponic systems. You can find varieties of perlite in liquid filtration systems, insulation, and even soap.   Perlite and Vermiculite are commonly mixed to create a blended hydroponic growing medium.
  • Coco Fiber – comes from the husk of coconuts.   This is an organic growing medium that is gaining support among hydronic growers.  It provides great moisture retention while at the same time allowing air to reach the roots.    It comes into two forms fiber and wood chips
  • Peat Pelletsthese can be used in systems such as the DIY Mason Jar – but not with any system that uses a pump to circulate water.  Has long as the water is not being circulated.   This is an inexpensive and readily available medium to start your plants.


For sprouting, I recommend Rock Wool, Grow Rock or if you are not going to use a pump – Peat Pellets.


If you are going to use Rockwool or Peat Pellets – you will need to soak your cubes and pellets in clean and pure water for up to one hour.   Into each hole in the starter, cubes insert between 2 – 4 seeds to make sure something sprouts.   After sprouting you can pinch (not pull) the weakest ones to leave one strong plant.  As for growing the sprouts add a diluted half nutrient solution into the tray.   Do not immerse them totally so that they are standing in water.    Believe or not roots need oxygen to grow.   Start feeding the sprouts with a correctly mixed nutrient solution to accelerate growth.    There are plenty of hydroponic nutrient solutions out there.  If you like an inexpensive start, try Miracle Grow’s Tomato water-soluble pant food – one ¼ teaspoon to one gallon of water.  1/8 for teaspoon for a diluted solution to begin with then as they sprout move it up to a ¼ teaspoon per gallon of water.


Once the seeds start sprouting, it’s time to intensify the plant lightly gradually by slowly moving the light closer daily until it’s 6” – 8” away from the plant.   A good LED is great for plants, while they cost more upfront, LED’s are very efficient and earth-friendly.   Fluorescents are more affordable and maybe a better choice if you are new to Hydroponics.


  • Move your seedlings once the roots start poking out of the starter cube this should be around 2 – 4 weeks depending on the type of plant.
  • Add the entire seedling and growing media into the hydroponic system you are using.   Add nutrient solutions to the transferred plants for a few days to train the plant on how to find its food source.


Seed Selection

As a beginner try to steer clear from root plants and I highly recommend Non-GMO seeds whenever possible.   An added benefit is you can find Heirloom Garden Seeds.   Heirloom Seeds are rediscovered historical varieties that can really surprise you.  The Heirloom Garden Seeds that I have linked you to gives you a nice variety of seeds.  For those that you can’t use in a Hydroponic System such as corn, pumpkin, and turnips – you can still plant them in a soil garden.  With the sale price of less than $16 for 34 packets – its a deal.  Sorry, I didn’t want to sound like a salesman here – but, this is a good deal no matter your preference on the garden system.  The most common plants you will seed in the Hydroponic systems are:

  • Greens like lettuce, spinach, Swiss chard, and kale.
  • Herbs like basil, parsley, oregano, cilantro, and mint.
  • Tomatoes – (I tend to lean towards and have great success with Cherry Tomatoes)
  • Mustard Greens
  • Strawberries are especially good.
  • Peppers (Hot and Sweet)
  • Radishes
  • Cucumbers
  • Beans (You will need a trellis or something to support pole beans)
  • Chives
  • Blueberries (It can be done – but in a more advanced system)
  • Scallions

In Summary

Hydroponic gardening can be a very satisfying adventure – but, like most adventures, it takes practice and to gain the skills and knowledge to be successful.   Start small with a DIY system and as you build to learn to be a successful move to more challenging projects.    I look forward to your comments and questions.   Yes, you can hydro grow.


  1. Thanks for the detailed information. You are correct in that it takes practice to gain the skills one needs to do this in a successful way.

    Patience as well but in the end it is well worth it.

    Thanks for sharing!

  2. I had no idea that there are so many options for materials for growing plants this way.my boyfriend is fascinated by this type of growing, which I didn’t know much about. Your post is very well done!

    • Thanks for dropping by – I am trying to show that there are options to get started from the DIY to as much as you would like to spend. Thanks for dropping by and the comment…

  3. Wow, great article!!! I was researching winter plantings in prep for spring. My wife gets an early start indoors in preparation for her spring plantings in the garden. Winters are cold and long here in the Northeast and now she’s interested in year round plants thanks to this article.
    Thanks for the tips, this is a great start for her. A question on the process though, are there any starter kits available that incorporate some of what you’ve outlined above? I’d think between that and the info on your website, she’d be sure to have a successful start.
    We’ll be sure to visit again to see what other gems of info she can find here.

    • Plenty of starter sets out there ranging in price from inexpensive to how crazy to you want to go. For example, the Freehawk Hydroponic System comes at under $35. I lean towards to the AeroGarden systems. Have had great success in the past and them. They range in price from about $70 to on up. Sometimes you can catch them on sale as I did with the Harvest Elite which I am going to do a product review on in the near future. Thanks for the comment….

  4. I think these would be a great option for growing some fresh produce during the winter as we a have a really short summer here. My father actually grows tomatoes and berries in their basement using LEDs and I’ve been thinking about trying it myself. I think the spinach really needed more light and warmth than your LED lights could produce since they thrived outside. Or do you think there might be some other factor?

    • Spinach grows really well outside, haven’t had much success indoors. Just purchased a Blue/Red light LED that I am trying out, it at least is getting seeds to sprout. Beleive it has something to do with the temperature. Will post my experience a little later on…. Thanks for dropping by come again.

  5. What a great deal of good information on hydroponic growing. Your article has some very useful information. This is something I’ve been curious about for a while now. Thanks so much for this post.

  6. Interesting article, I’ve heard about hydronic growing for years. I would like to get started at some point so i saved your website.

    any advice on micro greens? i have a kit.

    • Love microgreens and sprouting. My advice is finding the greens or sprouts you like. I’ve tried different mixes – the only one I am not too crazy about is Mong beans. My spouse loves them – I find them a little too harsh by themselves. Thanks for dropping by….

  7. Hi Steve,

    Many thanks for such an informative piece.

    What I found particularly striking is the variety of soils or sprouting medium as you call them. Frankly I was ignorant of the diversity.

    Thank you again for the piece.


    • I appreciate your dropping and commenting. Yes while there is not as many different types as it would be found in nature – there are some really basic mediums that hydroponic systems use.

  8. Hi Steve,
    Wow, I love your article.
    All the detail you provide will really help when I start my own.
    And now I know why I didn’t have much luck in the past, lol. Definitely a lighting problem.
    You’ve given me the hope to try again!

    • Lighting is definitely a major issue….Right now I working on some different approaches to see if they work. Plan to share my experiences in the not too distant future. Please feel free to visit and to ask questions if we can be of any help.

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