Hydroponic farming is one of the most efficient ways to take a frail, small plant and shelter it from the harsh world outside until it’s reached its maximum potential.
Even a basic hydroponic system can support the kind of exuberant plant growth that makes the Hanging Gardens of Babylon look like a window box.
Safe and protected, fragile seedlings and cuttings can quickly develop extensive root systems and abundant foliage that set the stage for success once moved to your outdoor garden. These fantastic growth rates make hydroponic gardening a great way to grow all types of plants for later transplant.
Whether you’re after higher yields from heirloom pepper plants or a growing tray of spring flowers to be ready for the first thaw, it’s easy to use a basic hydroponics setup to prepare to transplant hydroponic plants in soil.
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Why Transplant Hydroponic Plants in Soil?
With a bit of foresight, a hydroponic system can be the best way to get a head start on your traditional gardening.
For example, when you sprout early seedlings safely away from frosts before the growing season, you can develop sturdy plants that will be ready to be popped into the ground once the weather changes.
It’s also not uncommon for particularly vigorous plants, especially herbs, to crowd other plants in hydroponic rigs. You’ll get more from each square foot of your growing area if you move these overgrown beasts into containers or garden beds after sprouting.
After doing so, the plant’s roots should adapt quickly to their new environment, and you’ll be swimming in fresh basil, rosemary, or thyme for years to come, all while freeing up the space in your hydroponic growing systems for short croppers like leafy greens.
Benefits of Transplanting from Hydroponics to Soil
The use of hydroponics to sprout seeds and strike cuttings protects delicate new plants from rough weather, pests, and disease.
Planting hydroponic plants in soil is a good idea if your growing season is short or you have a lot of pesky birds or insects that love to eat newly planted seeds.
Get them going in a controlled environment, and you can also control their growth.
Grow lights provide light and allow you to prevent sun damage to fragile new leaves. The nutrient solution can even be tailored to each phase of growth, providing essential nutrients as the plant moves from the seedling stage and begins to mature.
It also allows you to select only the strongest, most healthy plants to put in your spring beds.
Traditional gardens encourage over-planting in the understanding that not all infant plants will survive. It’s a wasteful approach that results in more seeds spread and more time invested in plants that may not grow at all.
Starting your seedlings in hydroponics is far more efficient, allowing you to focus your attention on the strongest, best plants for your garden every time.
Risks of Transplanting from Hydroponics into Soil
The most significant risk of transplanting from hydroponics into soil is transplant shock.
This is a condition where damage to the roots reduces a plant’s resilience and effectiveness, leaving the transplanted plant at risk of dehydration, disease, or environmental damage.
The mechanics of hydroponics make their plants more vulnerable to transplant shock, especially those grown in hydroponic growing systems that feature exposed roots.
Deep Water Culture Systems (DWC) and Nutrient Film Technique Systems (NFT) encourage short, dense roots adapted to the wet, nutrient-rich water and environments found in grow trays and water reservoir tanks.
If you’re worried about your plants developing root rot in a hydroponic system, be sure to read our article on choosing the best hydroponic air pump for your plants!
The roots of plants grown in these systems simply aren’t robust enough to burrow through soil and actively seek out what they need to thrive. Because of this, you risk severe shock when transplanting from these systems into soil.
To successfully transplant from these systems, you will need to keep a close eye on every step of the process, and you may even need a bit of luck. (A prayer to the green thumb gods couldn’t hurt!)
The other biggest transplanting problem comes from environmental shock. Move your new transplants too quickly, and they won’t be ready for the fluctuating temperatures outdoors or the harshness of direct sunlight.
Symptoms of Transplant Shock
Plants suffering from transplant shock will show the following symptoms:
- Wilted Leaves, Stems, and Shoots
- Dropped Leaves
- Yellowing
- Slowed or Stalled Growth
Transplant shock often resembles dehydration. The stressed roots simply can’t get water up into the tissue of the plant itself.
While it’s tempting to treat it like dehydration and keep adding more and more water, the roots of the plants themselves are damaged and prone to dying off when they are allowed to become waterlogged.
Just hold back and allow the plant to recover.
How to Prevent Transplant Shock
You can lessen the impact of transplant shock on your hydroponic plants by planning ahead. With the right type of system – even a basic system – and the right medium, you can keep the shock to a minimum.
If you plan to start outdoor plants or trees in hydro, choose bedded systems like drip systems or wick system beds. Everything from citrus trees to cherry trees do well in these types of hydroponics!
Both of these growing techniques provide good stimulation to the root system, encouraging longer, tougher roots that endure the change to soil far better.
Ebb and flow hydroponics is also a good choice for those using hydroponics systems to get a head start.
Pick your medium with care, too.
Mixed blends of perlite, vermiculite, and an organic element like peat moss or coconut fiber can be left in place during the transplant process. It allows smaller seedlings to be relocated without their root ball ever becoming exposed to the air or manhandled in any way.
This makes these blends a popular medium choice among large-scale commercial growers, who often take this shortcut to produce higher yields and larger harvests without spending a long time fussing with their seedlings.
However, none of this will help much if you’re transplanting due to necessity.
A large plant that needs to go outdoors due to size may well be in clay pebbles, perlite, or Rockwool, with bare roots and lots of them.
You can still mitigate the damage by handling the roots as little as possible while transplanting them.
Planting Hydroponic Plants in Soil (Step-by-Step Guide)
Step 1: Prepare Your Transplant
Prepare seedlings or clones for transplant by reducing the frequency of their watering. Roots that have to work to find their water develop thicker walls and more lateral shoots, perfect for life in the soil.
For ebb and flow or drip system setups, give them less water than usual by programming longer intervals between watering in the period leading to transplanting. This practice ‘toughens’ the roots and prepares them for life in soil.
Step 2: Choose Your Pot
Pot size is critical to the success of your transplant process.
Choose a pot no more than two inches larger across than your root mass. It may be quite a small container for seedlings or a large pot for emergency relocation.
Pots must also have adequate drainage. Standard nursery pots with three to five holes at the bottom of the pot are perfect.
Step 3: Select and Prepare Your Growing Medium
Choose a soil-free medium with good water retention for bare-rooted plants previously grown in a Deep Water or Nutrient Film system.
DWC and NFT hydroponics are perfect for semi-aquatic plants like peace lilies or even Arum Lilies, which make a perfect addition to any indoor or outdoor pond or garden.
An equal mix of perlite, vermiculite, and an organic element like peat or coco coir is a perfect next step.
Seedlings from bedded systems started in this mix have a head start and can be planted into a conventional soil mix suited to the type of plant.
I recommend adding a water-retaining element like coir, peat, or vermiculite – it’ll ease the transition from richly watered hydro to more spartan soil.
Perlite is also a good additive as it improves aeration and will help the roots adapt quickly. The more plant respiration and carbon dioxide production that occurs, the better.
No matter the choice, fill the pot two-thirds of the way with your growing medium and create a small mound in the center of the pot for bare-rooted plants or a small well for bedded transplants.
If you have large plants, consider adding a stake or other support at this point.
It may take some time for the roots to become strong enough to hold the plant upright in addition to providing nutrient-enriched water.
Step 4: Relocate your Plant
Carefully remove the whole plant from the system and free it from any growing containers or plastic net pots.
For bare-rooted plants, carefully spread the roots over the mound of growing medium and gently cover. Pat the soil in place to ensure the plant is secure, and if you’ve opted to use a stake or support, now’s the time to tie your plant into position.
For formerly bedded plants, all you need to do is pop the lot straight into the well you’ve made.
Do not loosen the medium or tease out the roots. The less you can disturb the roots, the better your outcome will be.
Step 5: Prune if Required
Larger plants will do well to be pruned at this point, especially if they’ve come from a bare-rooted hydroponic setup.
Fewer leaves reduce the work the ailing roots need to perform, allowing them time to recover.
Trim the leaves back to reduce the work your roots need to do to support the plant. New shoots and outlying leaves can be neatly trimmed away and discarded if needed.
Step 6: Relocate and Rehydrate
Deeply water your newly potted plant. Pure water is best, as the roots are already stressed and don’t need the work of transporting minerals in addition to recovering.
You may find the content of the pot settles somewhat when you water, destabilizing your plant. Simply top up with a bit more medium of your choice. Once the plant is stable, return it to the grow room for now.
It’s almost inevitable you’ll see some wilting.
Moving from the relative luxury of hydroponics into even well-tended soil is a substantial change for all plants.
While the plant is wilted, keep the soil moist without allowing it to become waterlogged. If the water level in the soil overwhelms the damaged roots, it’s only a matter of time before they develop root rot.
Use only pure water, especially for plants in conventional potting mix.
Any fertilizer added before the plant is ready lingers in the soil, building up over time and causing problems of its own. Only once the plant perks back up can you water it with fertilizer.
Potted Exotic Pro Tip: Seaweed emulsion and kelp meal are excellent for formerly hydroponic plants. These fertilizers are rich in trace minerals, proteins, and naturally occurring plant hormones that promote root growth and can make a vital difference for a newly transplanted hydroponic plant.
Step 7: Harden Off Your Transplant
Once your plant has recovered from any transplant shock, you can consider its long-term future.
If you intend to grow it alongside your hydroponic garden, then congratulations! You’ve got a successful transplant that will grow quite comfortably close to its old home.
For others, it’s time to ‘harden off.’ Plants that will eventually wind up outdoors must be acclimatized to their new home in small, manageable steps.
The best time to start the process is roughly two weeks or so from when you intend to transplant.
Take your new transplants outdoors during the warmest part of the day, leaving them to adjust for two to three hours before bringing them indoors. Gradually extend this period of time until they are outdoors all day.
Any sudden change in temperature can quickly lead to transplant shock.
Next, allow the plants to spend a day or two outside overnight.
Finally, leave them outside in conditions close to where they will be planted.
During this time, gradually taper off the amount of water the plant receives. Increasingly dry conditions stimulate more lateral root growth and help prepare it for the great outdoors.
It’s important to harden off plants in containers that may not be going outdoors.
If your grow room is luxuriantly lit with warm and humid conditions all year round, even moving them to cooler, darker conditions indoors will require similar treatment.
Step 8: Final Relocations
Once hardened off, you can finally move your transplants out of their pots and into their garden bed.
Water the soil deeply, and dig a hole in your bed appropriate for the size of the plant.
Gently tap the plant from its pot, growing medium and all, and place it in the hole before filling it in.
Finally, mulch the new plant heavily and give it a good amount of water.
For best results, try to disturb the plant roots as little as possible, watching for new roots to grow with time.
It can be tempting to sweep away blended growing medium or potting soil, but it’s unnecessary. The organic matter in the growing medium will decompose in time and support root development until it does.
Inorganic elements like perlite and vermiculite perform much the same function in the ground as they do in a bucket.
If anything, the extra boost they provide will help the transplant become established.