Hydroponic Seeds: Everything Needed Before Starting Your Seedlings

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By Alex Harris

Hydroponics plants are a great way to improve the quality of your garden while also saving space.

But hydroponic plants have their own unique needs when it comes to hydration, nutrients, and light exposure.

Hydroponic plant seeds need more hydration than traditional seedlings because they do not receive water from soil or a hydroponic system. They also need more nutrients in order to grow.

There is no one-size-fits-all solution when it comes to hydroponics, but knowing what you’re getting into before starting your planting process can make things much easier for both you and your future harvest!

hydroponic seeds

Seeds Vs Seedlings

Seeds and seedlings both have their advantages. Seeds are easy to get, cheap, and produce a lot of plants quickly.

They also don’t require any extra growing space since they can grow in small spaces like eggshells or even coconuts! Seeds do take time though; it takes about three months for a seed to reach maturity.

Seedlings are faster and more reliable, taking only four weeks at most to start producing plants. They require less space but cost quite a bit more than seeds do due to the extra time spent growing them!

Starting Your Seeds

If you invest in a hydroponic starter kit, it will likely come with a bunch of seeds. This is the best way to get started since you know exactly what seed varieties they are and how much time it takes for them to grow.

But, if your kit doesn’t come with any seeds or if they aren’t working out for you (e.g. because some plants didn’t germinate), then you can start your seeds from seed.

If this is the route you are going, I recommend looking for heirloom or non-GMO varieties since they tend to have higher yields and better flavors.

Nutrients During Seeding

Many hydroponic systems provide nutrients to the plants throughout their lifetime, however, some are designed specifically for seeding.

Nutrients during seeding are beneficial because it encourages quick growth and can prevent nutrient deficiencies that may occur without these additional nutrients.

The amount of time you should introduce your supplemental water-soluble fertilizer depends on which system you’ve chosen, but you should typically add it within the first 24 or 48 hours of seed growth.

Check out our guide on the best hydroponic nutrients

Hydroponic-Ready Seed Starting Supplies

Once you have the seeds you want to use, the next is making sure you have the right supplies to kick start your hydroponic garden.

Here’s what you need to get started:

  • Grow tray with a fitted lid (ideally it should be vented to control the humidity)
  • Warming or heat mat to place directly under the tray (helps with seed germination)
  • A growing medium to germinate your seeds in, something like Rockwool or Rockwool cubes are fine
  • Distilled water that’s the half-nutrient solution (gives your seeds everything they need).

Frequently Asked Questions about hydroponic seeds

Here are the most common questions that growers have when seeding.

Do you need special seeds for hydroponics?

The answer is no. You can use the same seeds that you would plant in soil, but they must be started early to ensure germination before your system goes into flood and drain mode.

If you are using a seed starting kit for hydroponics, it will likely come with instructions on how to sprout your seeds specifically for this sort of system.

What seeds are suitable for hydroponics?

You can use the same seeds that you would plant in soil, but they must be started early to ensure germination before your system goes into flood and drain mode.

If you are using a seed starting kit for hydroponics, it will likely come with instructions on how to sprout your seeds specifically for this sort of system. Vegetable seeds, fruit seeds, herb seeds. They’re all the same.

How do you grow hydroponic seeds? (Germination)

To start growing your hydroponic seeds, first, fill your seedling tray with the growing media of choice and wet it thoroughly. Next, you want to plant one or two seeds per hole that you have created in your hydroponics starter kit.

You can then cover the seeded holes with a thin layer of additional growing medium and press down firmly on top to secure them into place.

Finally, you will want to water your hydroponic seedlings with a spray bottle. Make sure that the seeds are moist but not soaking wet or they could drown and die before ever sprouting into life.

Continue watering your seeds on a daily basis until they germinate – which takes about one to two weeks depending upon temperature and humidity.

What are “heirloom” seeds?

Heirloom seeds are seeds that have been passed down and cultivated for many generations. Many heirloom seeds are over 100 years old and they typically produce the best tasting fruits and vegetables, while also being more resilient to harsh weather conditions.

Can seeds grow in just water with hydroponic gardening?

If you are using a hydroponics starter kit, it will have an air stone in the water reservoir that keeps oxygen levels constant for your seeds.

Most kits also come with seed starting media mix – which is designed specially to promote germination when used alone or mixed half-and-half with soil. This growing medium helps to keep your seeds in place and it also has a high water content that keeps your hydroponics seedlings moist.

When should I start feeding my hydroponic seedlings?

Once your hydroponics seedlings have sprouted, you will want to start feeding them with a diluted nutrient solution.

If using an organic hydroponic fertilizer like worm castings or compost tea, give the plants one teaspoon of fertilizer per gallon every time you water for at least two weeks.

After that period is up, you can switch to a hydroponics base nutrient solution which you will then feed your seedlings at half the recommended strength.