Hydroponic Herb Gardens
Moving Seedlings into Hydroponic Planters



When herb seedlings are 2-3" tall and roots are growing out of the bottom of the cube, they're ready to be planted in a hydroponic planter. This is usually 2 weeks after planting - depending on the variety.


Hydroponic Herbs - mature seedlingWhen roots grow out the bottom of the grow cube it's time to move seedlings to hydroponic planters.


This is Step #2 of growing herbs with hydroponics. (See Step #1 here.)


What Size Hydroponic Planter Should You Use?

Unlike orchids or houseplants, the size of the hydro planter for growing herbs is not critical for success. 

In fact, planter size can be determined by whatever fits best in your growing area (windowsill, under lights, etc.).


Hydroponic Herbs - assortment of hydroponic plantersHydroponic Planters come in many sizes

4" Hydro Planter

Perfect for windowsills. Typically holds 2 grow cubes.

5" Hydro Planter

Our most popular size. Works well on windowsills. Holds 3-4 grow cubes

7" Hydro Planter

For larger growing areas - typically holds 5-7 cubes.

6", 7" or 9" tall profile Hydro Planters

Planters for larger crops. Tall planters come in 6", 7" and 9" sizes and hold 5-9 grow cubes.


Let's Plant!

For this project we're planting several varieties of lettuce in the same pot.


Grower Tip: To grow full, healthy looking plants, always use several grow cubes per pot. See chart above. 



1. Soak LECA pebbles for several hours in clear water.  No nutrients yet.


2. Cut plastic cover on grow cube with a scissors and remove it. The plastic cover holds in moisture while seedlings are growing. Won't be needing it anymore.

Hydroponic Herbs - preparing rockwool seedling for planting


3. Fill the bottom of the grow pot with pebbles. 

Hydroponic Herbs - preparing hydroponic pot


4. Position plant (and Grow Cube) on top of pebbles (plant entire cube - don't try removing plant!). Planting depth for seedlings is important. For a smooth transition new roots should be close to - or in contact with the water when planter is watered to maximum.

Hydroponic Herbs - preparing hydroponic potPencil marks maximum water level - that's where Grow Cube will be planted.


5. Holding plants (and cube) in position, add more pebbles. If seedlings are too high - they won't reach the water. Too low and the leaves will be buried. If planting depth isn't right, lay culture pot on its side, slide out grow cubes and start over.

Hydroponic Herbs - planting rockwool cubes

6. When Grow Cubes are in postion, carefully add pebbles to fill in the gaps between the cubes. This can be tricky the first couple of times. Don't worry about damaging seedlings - they're tougher than they look. 


Hydroponic Herbs - planting herbs growing in rockwool into hydroponic planters


6. Pack down pebbles. Be aggressive so plants are stable in their new pot. Don't worry about damaging the roots or "squishing" the grow cubes.


Hydroponic Herbs - planting herbs growing in rockwool into hydroponic planters


7. Insert water gauge and place culture pot in outer pot. Your seedlings might look disheveled at this point. No worries, they'll perk up in a day or two with a little sun.

Hydroponic Herbs - finished planting



Watering and Nutrients 

Hydroponic Herbs - Diagram of hydroponic planter

A water gauge tells you when and how much to water. No green thumb required because with our system you'll get the watering right every time!

Pour nutrient solution over pebbles until water gauge reads maximum. When water gauge reads minimum, rewater immediately. Unlike most plants, herbs do not need a dry period between waterings. 

Now, while you go about your busy life, the LECA pebbles will wick the nutrient solution up to the plant gently and evenly. The water gauge tells you when and how much to water. No more guessing!


Hydroponic Herbs - the Dyna-Gro nutrients you should be using

Start applying nutrients at full strength immediately. These young plants are hungry!

For best results I use and recommend Dyna-Gro "Grow" 7-9-5 formula 1 tsp. per gallon every watering.



Grower Tip:  Resist the temptation to "top off" the system to keep the reservoir full at all times. Allow enough time between waterings for the water gauge to read empty before rewatering. Roots need air as much as they need water to grow! 



Hydroponic Herbs - growing in hydroponic plantersMature planter 5 weeks later


Why Hydroponics?

How to Grow from Seeds

Tools for Success