The 7 Best Hydroponic Seeds For Indoor Gardening (2024)

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Brock Ingham
Brock Ingham

Whether you choose to grow plants as a hobby or for a living, there are some added benefits to owning a hydroponic garden. So why are some seeds better suited for hydroponics than others? Not all plant varieties do well in the closed conditions of a hydroponic kit. That’s why it’s important to choose the right varieties to save yourself the headache of growing too big for your bridges.

Let me take you through my list of the 7 best seeds for hydroponic growing and where to buy them. From flowers to carrots here are seeds you are going to want to grow.

hydroponic seeds
Some of the hydroponic seeds I use

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Which Seeds Do Well in Hydroponic Systems

There are a few vegetables and herbs that do exceptionally well in hydroponics these seeds include tomatoes, peppers, lettuce, broccoli, and leafy herbs like dill, mint, and oregano. This is because they all have root systems that benefit from constant moisture.

Another added benefit is that hydroponic gardens save an enormous amount of space. Vertical growing systems in particular are ideal space savers.

In this article, I will be exploring what kind of seeds are best grown hydroponically, what to grow them in, and how to grow them.

Sound interesting? Let’s get started!

Growing Vegetables Hydroponically

Lettuce Seeds

Lettuce is a great starter plant for beginners as it grows fast and responds well to hydroponic systems, especially for smaller setups like the AeroGarden. On average, lettuce is usually ready to harvest in as little as 3 weeks especially when you opt for cut salad blends like the Fast and Furious from West Coast Seeds. You’ll be chomping on salad in no time!

Matures in 35-40 days
Super Gourmet Salad Blend

Fast and Furious Lettuce Blend

Grow your own babyleaf Fast and Furious Blend Organic lettuce seeds with this blend of whole line of organic babyleaf lettuce varieties. Enjoy the contrast in color, flavor, and texture from freshly cut salad greens. These fast-growing seeds are perfect for hydroponics and aquaponics.

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Tomato Seeds

Tomatoes are a great choice of seed whether planted outdoors, in a greenhouse, or hydroponically. Hydroponic tomatoes are easy to maintain and there are many different space-saving varieties to choose from. Tomatoes require heavy amounts of water making this vegetable the perfect candidate for hydroponics. Dwarf Cherry or Grape Tomatoes offer more bang for your buck and don’t require the width and height of Beefsteak varieties.

Matures in 50-55 days
Red Robin Tomatoes

Red Robin Dwarf Tomatoes

Red Robin tomato seeds produce hardy, compact dwarf plants that deliver high yields of delicious cherry tomatoes. Plants will set fruit in lower light indoor conditions and still deliver moderate yields of sweet cherry tomatoes.

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Pepper Seeds

You can grow peppers, or anything on this list in fact, at any time of year using a hydroponic garden. No more waiting until April/May/June to begin planting your seeds, these indoor environments allow growth whatever the time of year.

Peppers have the ability to grow much larger and are on average, much tastier than those grown in soil. If your working with a compact hobby grow space like mine then growing a smaller thick-walled pepper will be your best option.

Matures in 65 days
Right on red

Right On Red Compact Peppers

Right on Red is part of the Hungarian Cheese series of peppers. These are round and squat and slightly flattened, with thick, succulent walls. Starting green, Right on Red ripens to a very sweet, very red finish, and it stores well after harvest. The plants are robust and fast-growing, making them the perfect companion in your hydroponic setup.

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Broccoli Seeds

Broccoli is fast-growing but requires more maintenance than other seeds. Therefore, it may not be the best vegetable to consider growing if you are a beginner. That being said, Hydroponic broccoli with the proper care will offer a bounty of fresh sprigs for months to come.

Matures in 50 days
Aspabroc Broccolini

Aspabroc Broccolini

This delicious broccolini resembles a broccoli raab, but with an asparagus-like stem that’s perfect for continuous picking. Aspabroc Broccolini has a sweet, delicate flavor with a subtle, peppery taste. Aspabroc broccolini seeds are a natural hybrid of broccoli and gai lan and are not genetically engineered.

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Flower Seeds

Lavender, Carnations, and Chrysanthemums are just a few flowers that do well when grown hydroponically. Hydroponic flowers tend to thrive better in these indoor environments than outdoors due to the controlled system and lack of overwhelming weeds. My favorite here has to be the English lavender varieties. With flowering beginning in the first year you can expect fragrant aromatics sooner than most perennial flowers.

germinates in 14-21 days (Perennial)
Blue Spear Lavender

Blue Spear Lavender

This brand new cultivar of English lavender is hardy and blooms in the first year, so you won’t have to wait to enjoy your hydroponic flowers. It is the tallest and showiest of the first-year-blooming types, with decidedly blue-tinted flower spikes over subdued grey-green foliage. With a height of only 28-33cm (11-13″) it will grow well in most indoor setups.

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Which Seeds Do Not Do Well in Hydroponics?

Unfortunately, not everything grown in a hydroponic setting will be successful. Seeds that do not grow well in hydroponics include corn, potatoes, zucchini, onions, carrots and most other root vegetables. The amount of water available to these plants from hydroponics will prevent the healthy growth needed for a full harvest.

Large Fruits or Vegetables

It is extremely difficult to grow fruits and vegetables such as melons, zucchini, watermelons and corn. Not only do they need room to grow, some bare a lot of weight and can therefore be difficult to manage if you have limited space.

Potatoes

Potatoes outdoors

Both potatoes and sweet potatoes do not adapt well to hydroponic systems as they require plenty of sandy soil to grow and mature. Another reason is that the roots need space to grow, something which there is minimal room for in a typical hydroponic garden. While it’s an uphill battle growing potatoes hydroponically it is possible given the right conditions and care.

Carrots

The same can be said for carrots, and other root vegetables that need plenty of room and soil to thrive. Hydroponic carrots are not impossible to grow, but it will be an uphill battle to grow one similar in quality to what you can get from an outdoor garden. plan for small tender roots and harvest regularly for best results. Royal Chantenay Carrots provide a compact taproot that will be able to stay above the waterline of most larger Deep Water Culture systems.

Matures in 70 days
Royal Chantenay Carrots

Royal Chantenay Carrots

Expect good flavor and an ideal shape for juicing. Also good for freezing and canning. These big, dark orange carrots are 12-15cm (5-6″) long, amazingly sweet. Royal Chantenay carrot seeds produce roots that grow to a uniform size and shape and are not picky about where they grow. These carrot seeds will be your best chance at growing hydroponically.

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Onions

As a root vegetable, onions are also difficult to grow indoors. The root or bulb of the onion requires room to spread and search for light and moisture. If you’re set on growing onions in your hydroponic setup, try planting green onion seeds. They are able to handle a variety of conditions and will not need to expand like other varieties of onions.

Matures in 50 days
Kincho Green Onions

Kincho Green Onions (scallion)

Kincho scallion seeds are Japanese type scallions with dark-green leaves and tall, straight, single-stalk stems that do not bulb. Kincho maintains a uniform thickness along its whole length, and they look great bunched on the market table. The flavour is bright, and the texture is crisp, so it’s just right for slicing.

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The Best Growing Medium For Hydroponic Seeds

So, how does a seed grow without soil? Let’s take a look at the best-growing mediums for these special seeds.

Rockwool

Rockwool is an inorganic material that is mostly used for soundproofing and insulation. It is made out of molten minerals, or rocks such as ceramics and slag.

In hydroponics, rockwool cubes are popular as they are a great source of insulation, they’re cheap, and they take up minimal space. Rockwool is pH neutral and is good at retaining moisture and oxygen; both of which are essential for a plant to thrive.

Clay Pebbles

Unlike rockwool or grow sponges clay pebbles offer an eco-friendly option to our hydroponic unit. These brown little spheres are easy to handle, and easy to clean allowing for re-use time and again. Clay pebbles are porous allowing them to hold water and nutrients vital for plant growth.

Grow Sponge

A grow sponge (as seen in AeroGarden kits), is made from peat moss (a soil amendment derived from peat bogs). They are used in hydroponics since they are affordable, lightweight, and retain a good amount of water. This water retention is important to mention as while the sponge is porous, it does not lie heavy on the roots of the plant.

Grow Bowls

Grow bowls are ideal for growing smaller fruits and vegetables such as strawberries, herbs, peppers, tomatoes, etc. These devices are a complete grow system for plants providing space to plant seeds with lights to grow under.

They are small, compact and able to hold multiple seedlings at once which makes them perfect for even the smallest indoor spaces.

How to Grow The Best Plants Hydroponically

Now you’ve read about what to plant and where to plant them, you’ll need to know how to care for your hydroponic plants. I’ll take you through everything you need to know about growing the best plants hydroponically.

Hydroponic seeds

Spacing

Spacing is incredibly important when it comes to gardening outdoors, and it is just as vital in hydroponics. If your plants are too close together, there is a high chance that growing foliage will not have access to the light it requires. Therefore, I would heavily recommend keeping tabs on your crops and trimming them down as and when needed to prevent crowding. Leafy herbs like dill needs constant pruning to prevent flowering and stimulate growth.

Once indoor plants begin to grow into adults, it is at this point when growers tend to think about transplanting outdoors (I will go into detail more about this further down the article).

Avoid Cross Pollination (Unless Intentional)

Traditional gardening often requires pollination, which is provided by bees and the wind. The same cannot be said for hydroponic systems.

While human intervention is the only way to pollinate indoor plants, you will find that many seeds planted hydroponically are of the self-pollinating kind. Vegetables such as tomatoes, peppers and peas, are all self-pollinating.

For those that do require pollination such as strawberries or cucumbers, there is a chance that pollen grains from each variation may cross over onto one another, thus resulting in a new variety of strawberry/cucumber.

While some growers purposely cross pollinate, there is a chance that the final product may not meet the requirements.

Nutrients and Plant Food

Plants require a total of 17 nutrients in order to successfully thrive. Therefore, it is essential to provide your crops with a good amount of nutrition.

Unfortunately, plants grown in hydroponic systems are less forgiving than those grown outdoors. So keeping an eye on nutrient consumption is key.

Water PH and TDS

Both the water pH and TDS (Total Dissolved Solids) must be up to scratch to grow healthy crops. So what are they?

Water pH (power of hydrogen) refers to the level of acidity or alkalinity in water. When it comes to gardening, this level should be between 5.5 and 6.5. If this pH level is too acidic, the plant will absorb too many nutrients. If too alkaline, the plant will find it hard to absorb any nutrients at all. Water is the foundation of the nutrient solution, so it is important to consistently check the pH levels.

Similarly, the TDS levels show how much salt and nutrients are available. TDS levels of 600 to 1000 are regarded as good, with 800 being almost perfect. If these levels are too low or too high, it can cause irreversible damage to your plants.

Care (Trimming)

Once your seeds have sprouted, your plants will begin to grow rapidly – which can sometimes become chaotic and stressful. I would recommend taking time out of your day (this could be a few minutes or even an hour depending on how big your system is) to tend to your growing plants to make sure they are getting all the essentials.

This will include trimming, misting, and repositioning your crops to ensure they have ample space and moisture to thrive.

Algae on growing medium

Cleaning (to Avoid Algae)

It is essential to keep your hydroponic system clean and free from algae, bacteria and pathogens. All of which can damage or even kill plants very quickly.

In order to ensure your indoor growing environment is clean, you will need to sanitize and sterilize the area frequently, especially after a harvest. There are many accessories to help you do so and they key is to keep on top of it by putting a cleaning schedule in place.

Transplanting your Hydroponic Plants

You may be wondering why anyone would choose to transplant indoor plants to an outdoor environment. Well, this could be for a number of reasons. Hydroponic growers choose to transplant crops when they have matured slightly and are ready for a life outdoors. For example, you may need to free up space, or you may have decided early on to transplant them outside once they begin to flourish.

Whatever the reason, you may wonder how to do it. Our step-by-step guide below is a good starting point. Let’s take a look.

Step #1: Lower The Amount of Water For Hydroponic Plants

About a week or so before the ‘big move’ you will need to reduce the amount of water you give to your indoor crops. This manipulates the roots so that they grow slightly and prepares them to search for water once in soil.

Step #2: Transfer Into a New Pot

Before transplanting outdoors, you will firstly need to move the plant into a pot of its own to help toughen up the cells before it is moved outside.

A pot that is around 6 inches in diameter will suffice as the roots need space to spread (if transplanting a seedling).

Step #3: Fill It Up With Soil

To give your plant the best chance in the great outdoors, you should introduce it to soil early on. Filling your plant pot with potting soil. The softer and ample the texture and aeration is, the more space your seedling will have to grow successfully. Before adding the soil, you should mix with water in a separate pot. Be careful not to completely drown the soil in water as this could lead to root rot which will destroy the plant.

Step #4: Transfer The Plant To The Pot

To do this, simply dig into the soil with a large spoon to make enough room for the plant and its roots. This should be done quickly to prevent any damage. Therefore, if you are transplanting multiple plants, have the pots lined up and ready for the move. You may even want to trim or remove some of the leaves before transferring to minimize the risk of damage.

Step #5: Mist Your Transplants

Although the soil in the pots will already be moist, you should continue to mist the soil daily for at least a week. Adding fertilizer to your misting spray is essential so that your plant continues to receive nutrients.

After one week, you can reduce misting to once a week. Once the plant becomes accustomed to the new environment, watering will not be required as frequently.

Step #6: Let Them Toughen Up

By this, I don’t mean place them outside immediately in high wind speeds. This is a gradual process, so I would recommend firstly moving them into a room where there is plenty of natural sunlight.

Keep a close watch on your plant/s over the next few days. If you see any negative changes, try taking them away from direct sunlight and ensure the soil is moist.

Let them sit outside for an hour or two during the warmest times of the day and gradually extend this period until they are eventually outside permanently.

Hydroponic tomatoes

Hydroponic Seeds: FAQ Section

Take a look at my FAQ section to see if I can answer your question.

Are Seeds Better Than Clippings?

This depends on the plant in question but generally there is no right or wrong answer. While it is true that cuttings mature quicker than seedlings, there is also a chance that the original plant may have been affected by disease or pests which can therefore affect the plant you are trying to grow.

What Are Heirloom Seeds?

Heirloom seeds are seeds that have been passed down through generations, just like an heirloom. Such seeds are known for their distinguishable flavoring, adaptability or hardiness. Heirloom seeds are used to ensure a grower produces the same crop or plant year after year with the same great qualities.

What Are Dwarf Variety Seeds?

These are used to grow miniature versions of plants and vegetables. For example, cherry tomatoes, baby artichokes and green beans grown from dwarf seeds. These are ideal for hydroponic gardens as they require less space to grow.

When Should You Start Feeding Seedlings?

What most people love about hydroponics is that they are very low maintenance, particularly for the first week or two of growing. You should think about feeding seedlings once the first true leaves have formed

Final thoughts

I hope you have learned something new about what seeds to use when it comes to hydroponics. If you are a newbie, or a keen grower yet to plant indoors, growing hydroponic seeds is a brilliant and interesting way of taking seeds to fully-grown crops.

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