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How to prepare pots and plant sprouts.

Prepare pots in advance so sprouts can be immediately transplanted once they are ready. 

The ideal size pot for planting your seedlings is 4” size. Use 4” pots and not a larger size because a 4” size pot produces a plant with a tight root ball that is easy to transplant later. With a larger sized pot, you’ll get looser, more spread out roots, which are bad because they are prone to getting torn or damaged during transplant. Another benefit of 4″ pots is faster top growth.  Small pots constrain plant roots which forces growth upwards. When their roots are allowed to expand their growth outwards a plants top growth is slower.  

Pack pots with grow media. On the bottom of the pot, add a 1” layer of hydroton. Hydroton prevents water buildup on the bottom of the pot and creates air pockets so roots get access to air. Fill the rest of the pot with coco coir.  

Pre-water the coco coir with distilled water, or tap water pH balanced to 5.8 prior to adding sprouts to the pots.

Planting Sprouts

To plant your sprouts, first make a hole in the coco coir to plant your sprout in. The end of a tube is a good tool for this. The hole should be deep enough that your sprout’s tap root fits all the way inside. Drop your sprout into the hole using your fingertips so its tail is positioned down. If you miss, and the tail isn’t pointing down, it’s usually better to leave it misaligned than keep poking at it and risking damage. The tail will naturally revert itself and point back down on its own as it grows longer.

Bury sprout 1 cm deep.

Gently backfill the indent with the coco coir until your sprout is completely covered. It shouldn’t be buried that deep, no more than 0.25” (0.635 cm) of medium on top.

Water & Nutrients For Seedlings

Water pots using a watering can with a wide distribution and slowly pour until water starts to drain out the bottom of the pot. When it starts to drain out the bottom you’ll know you’ve added enough water. Do not add water past the point it starts draining because an over saturated medium will suffocate sprouts. 

Remember the weight of the pot when it is fully watered so later you can pick it up and judge if it needs more water or not by how heavy it feels. As a general guideline, plan to water every 2 days at first, then switch to every day when your seedlings get bigger. Never water past the point it starts to drain out the bottom.

For the initial watering use distilled water, or tap water pH balanced to 5.8. Once seedlings appear and their first two baby leaves begin to yellow, begin adding fertilizer at the following concentration:


350 – 500 TDS

0.7 – 1 EC

During the first week of growth extra phosphorus in fertilizer is beneficial for seedlings.

Adding 2 parts kelp extract / 5 parts humic acid will help enhance root growth. 

Excessive chlorine can be harmful to roots. Remove chlorine using vitamin C (ascorbic acid) tablets or a water filter.

Lighting For Seedlings

Add light after your sprouts emerge from the media. Lights for seedlings can be left on 16-24 hours per day.


100 PPFD

5,000 – 7,000 LUX

Delicate seedlings can be damaged by excessive light. Start with low light levels and raise it gradually.

Don’t allow the stems to become elongated and spindly. If you observe any stretching, increasing light intensity fixes this problem.

To encourage rooting, use a full spectrum light with emphasis on blue wavelengths. Red wavelengths are not ideal for seedlings because they promote stem elongation at the expense of root development.

LED or florecent Tube lighting is common for nurseries. The correct type of bulb is often labelled cool white.

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How to transplant seedlings to larger pots.

The more branches there are on a plant, the more clones it will yield. Shorter, bushier plants with more branches make better mother plants than plants with long stems and fewer branches. To encourage more branch growth, transplant in 2” pot size increments as plants get bigger. For example, from a 4” pot to 6” pot, from 6” pot to 8” pot and so on. This technique constrains roots, which has the effect of forcing more branches to grow.

How To Know When It’s Time To Transplant

Without sufficient roots to hold it together, media will be loose and will fall apart during a transplant, causing unwanted root stress and damage. Before transplanting, check first to see if there are roots growing out of the drainage hole at the bottom of the pot. This is a good sign that roots are developed enough to handle a transplant. Another good sign your roots are mature enough is the diameter of the plant’s top canopy is wider than the diameter of the pot. The diameter of the canopy mirrors the diameter of the root ball, and a wide canopy suggests that the root system has developed to the outer perimeter of the pot.

Roots growing out bottom, and top canopy with a wider diameter than the pot are signs that plant is ready to be transplanted.

Setting Up A Fresh Pot For Transplant

The first step for preparing a new pot is adding a layer of hydroton to its bottom. For 6” – 8” pots, use 1” of hydroton. For 10” and wider pots, use 1.5” of hydroton. Hydroton is added to the bottom of pots because it creates air pockets that help with drainage and provide plant roots with air access.

Fill the new pot with coco coir, with the outgoing pot nested inside it. Pour a mix of 90% coco coir, 10% hydroton between the old and new pots, saturate it with treated water, then push it down with your fingers until it feels firm. 

Add a mix of 90% coco coir, 10% hydroton.
Add water.
pack down.

Remove the old pot using a twisting motion. The coco coir in the new pot will have a convenient indent ready to receive a new rootball.

New pot is ready to receive transplant.

Performing A Transplant

Secure the stem of the plant you are transplanting between your fingers, and its base with your palm. Then flip the pot upside down. The plant might simply fall out into your palm. If it doesn’t, with your other hand push your finger into the drainage hole at the bottom of the pot to dislodge the rootball. The rootball should come out as one piece with little mess.

Hand position for transplanting rootball.

Once the plug is removed from the old pot, drop it into the indent in the media in the new pot. Perform the transplant quickly because roots shouldn’t be exposed for any length of time. 

Add some additional coco coir to fill in any gaps. Pack the coco coir tightly around the rootball.

Finishing Up

After the plant has been successfully moved to the new pot, add 1” of sand on top. The sand helps prevent insects from getting into the coco coir and laying eggs. 

Sand on top provides a protective barrier against pest infestation.

As a last step, lay down a layer of hydroton. Hydroton helps with even distribution of water and maintaining the integrity of the sand barrier. Without the hydroton, coco coir can float up over the sand during watering.