Grodan® in Cloth Containers

More and more growers enjoy the ease of using cloth containers such as the Smart Pot®. Cloth containers are lightweight, re-usable and have air-pruning properties. The larger ones work great for simple hand-watering while the smaller ones lend themselves to ebb and flow systems. Many growers use soil-less mixes, coco coir or clay balls, but you can grow smarter by using Grodan Grow-Cubes™, Grow-Chunks™, or Absorbent granulate!

Tomatoes grown in Grow-Cubes on left vs. clay balls on right using Smart Pots on an ebb and flow table.

Why Grodan?

Overall, stonewool induces more of the hair-like roots called “feeder” roots than other media. These feeder roots take up the most nutrients. So the more feeder roots, the faster and bigger your plant will grow.

Why hand-water Absorbent Granulate?
(See steps below)
Because it is cleaner than soil-less mixes. Plus you can reduce your watering and nutrients by half, while still achieving spectacular growth. This saves time and money.

Why use Grow-Cubes (small croutons) or Grow-Chunks (large croutons) with ebb and flow?
(See steps below)
Because, if your pump dies, grodan provides a buffer of moisture that is non-existent with clay balls. You can also reduce the frequency of watering (when switching from clay balls to grodan), therefore extending the life of the pump. If you prefer using a mix, use Grow-Cubes as their smaller size blends easier with clay balls.

Hand watering in large cloth pots

Step 1

Soak Absorbent Granulate in pH 5.5 for at least 30 minutes.
Make veg nutrient solution for transplants (EC 1.5 at pH 5.5 works well)
Use cloth pots that are at least 5 gallon size for hand watering.

Step 2

Place soaked Granulate in the large cloth containers and allow to drain to waste.
Pour at least 5 gallons of the nutrient solution made in Step 1 over each container of Granulate. This flushes out any excess lime in the Granulate.
You are now ready to transplant into the containers.

Step 3

We recommend using Grodan starters and Gro-Blocks™ for the best transplants, but you can transplant from any medium into the granulate.
Carefully transplant each plant into the cloth containers.
Water once per week. 1 gallon of nutrients solution works for a 5-gal size cloth container. Use a pH of 6.0 and increase EC as plants grow.
With coco and soil-less mixes you would have to water twice that amount for the same results– wasting time and nutrients!
Switch to a bloom solution when plants start flowering.
Depending on maturity of plant and your environment, you may need to water more often, but always less than most potting mixes.

Small cloth pots in Ebb and Flow

Step 1

Soak either Grow-cubes (small croutons) or Grow-chunks (larger croutons) in water. IF you have hard water, use pH 5.5 water for 30 min.
Make veg nutrient solution for transplants (EC 1.5 at pH 5.5 works well)
Use 1-2 gallon size cloth containers on ebb and flow tables.

Step 2

Place soaked croutons in the cloth containers and allow to drain to waste.
Pour at least 1 gal of the nutrient solution made in Step 1 over each container. This flushes out the croutons and fills them with some nutrients.
You are now ready to transplant into the containers.

Step 3

We recommend using Grodan starters and Gro-Blocks™ for the best transplants, but you can transplant from any medium into the croutons.
Carefully transplant each plant into the cloth containers.
Set your pump to flood 3 times per day initially. You can increase the frequency to 6 times per day when plants mature. Depending on you environment, you may be able to flood with less frequency or may need a few more cycles. However, the frequency of watering will always be less than when using clay balls.
A pH of 6.0 works well. Start with EC of 1.5 gradually increasing it as your plants mature.

Step 4

At flowering, switch to a bloom solution.
Make sure you stake your plants well as they grow.
If you want to mix in clay balls with some Grodan, we recommend the Grow-cubes since they are small enough to mix easily with the balls.
Granulate can also be used in flood trays, but only water once per day max.
When done, easily mix in your old Grodan in your garden or compost pile. Or re-use in the smart pot for a different type of plant! See our recycling tips.