Hydroponic Herbs
Growing From Seeds 

Growing herbs from seeds - new seedlingNew seedlings 1 week after planting. Notice the shell from the seed at the tip of the new leaf.

The miracle of seeds! Every seed contains all the food and energy it needs to burst out of its shell and start growing. Just add water.

Growing from seeds with soil can be a delicate process. Too much water and fungus attacks. Not enough water and new tender seedlings shrivel up and die.

Watering has to be "just right" for success.  

Growing herbs from seeds - plants die in soilYoung, tender seedlings suffer without special care

We replace soil with "Rockwool Grow Cubes" - a new and unique way to nurture seeds into seedlings. Rockwool Grow Cubes are a sterile growing medium that resists disease and provides the exact balance of air and water that seeds need to sprout. 

Growing herbs from seeds - using rockwool cubesRockwool Grow Cubes

more on Rockwool Grow Cubes  . . . 

Growing herbs from seeds - seedlings in rockwool cubesMature lettuce seedling growing in a Rockwool Cube

Planting Seeds in Rockwool Grow Cubes

1. Soak Rockwool Grow Cubes in clear water until they're saturated - about 10-15 minutes.

Position saturated cubes in a watertight tray for planting. Any type of tray or saucer will work.

Growing herbs from seeds - rockwool cubes in pastic saucerRockwool Grow Cubes in a plastic saucer

2. Using a pointed object (like a pencil) poke several holes in the top of each cube. 

Growing herbs - planting seeds in Rockwool cubesPreparing rockwool grow cubes for planting

3. Carefully sprinkle seeds over saturated cubes. Try to get the seeds to fall into the holes - don't worry if you miss - they'll still grow.

Growing herbs - planting seeds in rockwoolcubesPlanting seeds

4. Cover seeds with a layer of sand to protect the seed and to block out light. Any type of builders sand will work.

Growing herbs - protecting seeds with sandCover seeds with sand for protection as they open.

Good job!

Now, be sure to use labels so you know what you've planted. (you think you'll remember - but you won't.)

Getting Your Seeds to Sprout (Germinate)

Getting seeds to germinate is a delicate process that requires two things; 

  1. warm temperatures 
  2. just the right amount of moisture.

Growing herbs from seeds - you should be using a heat matHeat mats provide the gentle wramth seeds need to sprout

1. Warm Temperatures

Temperatures in the 68- 75 degree range are imperative. Most seeds simply won't germinate in temperatures below 68 degrees. Temperature is more important than light for sprouting seeds.

Heat mats are the best tool for providing the gentle warmth seeds need to sprout.


2. Just the Right Amount of Water

Watering seeds growing in soil is never easy. Seeds are easily dislodged or damaged. 

And, if they're too wet, disease sets in quickly (especially a fungus called "damping off" where new seedlings decay at the base and the plants fall over and die).

Growing herbs from seeds - Rockwool cubes

Accurate watering is easy with Rockwool Grow Cubes. Simply pour water into the tray (not on the cubes) to about 1/4" deep. Use plain water - no nutrients yet. The capillary properties of the Grow Cubes will pull moisture up to the seeds gently and evenly. At the same time, air flows through the cubes creating an even balance of air and moisture, preventing fungus and disease.


Most seeds germinate better in the dark. (Always read the seed packet before planting.)

But, when new leaves emerge (in 5-7 days), the new seedlings want  light - and lots of it! After seeds sprout, move them to sunny window that gets a couple of hours of direct sun.

New seedlings will grow weak and spindly without adequate light..

Growing herbs from seeds - tray of new seedlingsSeedlings growing in Rockwool Cubes - 2 weeks after planting.

Most seeds sprout in 5-7 days. After 2-3 weeks in a sunny window (or under grow ights) you'll have mature seedlings that are 3-4" tall and are ready to be moved into a hydroponic planter.

herbs - basil seedlingBasil seedling ready to be moved into a hydroponic planter.

Grower Tips for Seeds and Seedlings:

  - Use plain water while seeds are sprouting. After new leaves appear apply nutrients at 1/2 strength. I use and recommend Dyna-Gro Grow 7-9-5 formula.

 - As seedlings mature they will gradually use more water. Always wait until tray is dry to touch before rewatering however.

 - Avoid harsh, dry heat when warming seeds for germination. Top of a refrigerator or few inches above a radiator simply aren't the best spots. Kitchen counters are better - or - for the best results everytime - invest in a heat mat!

Moving Seedlings to Hydro Planters

Hydroponic Herb Gardens - Tools for Success

Why Hydroponics?