These instructions represent a combination of' information, my personal views and feedback from customers on starting seeds in rockwool.

To start larger seeds, such as beans, we always prefer using the wet paper towel method. Take a styrofoam picnic plate with one sheet of paper towel that has been cut to fit the bottom of the plate. Spray the towel with a one-third strength fertilizer. Space your seeds on the towel. Another piece of towel is then placed on top of the seeds and sprayed thoroughly. Drain the plate of excess solution and place it in a large ziplock bag. Put the bag in a warm (75 to 85F) dark location. The plate should be kept in an upright position. Check for germination of seeds twice daily by holding the bottom of the plate to a light and looking for the development of roots. By keeping the plates vertical, all roots will point downward. Occasionally you might have to add more solution to keep the paper towels moist. When you see a root developing (approximately 1/8 to 1/4" long), put the seed, root pointed downward, into an AO 36/40 rockwool growing cube that has been thoroughly soaked in a two-thirds strength nutrient solution of approximately 5.8 pH. You can cover the seeds with a little perlite if desired.

Many people skip the paper towel method and place the seeds directly into a cube that has been watered with a one-third strength solution. This is usually the case when starting a large number of seeds or when working with small seeds, such as basil or lettuce.

Water with nutrient solution when the rockwool reaches 60% of its saturated weight. An easy Way for the hobbyist to check the need for watering is to squeeze the cubes very lightly. If no water drips out of the cubes, it's time to water with the full-strength nutrient solution. Of the day's total watering, 20 to 30% of the solution should come out the bottom of the block and be disposed of.

When 4 to 7 healthy white roots have penetrated the base of the cubes, they are ready for transplanting into a larger plastic wrapped growing blocks. The cubes should be soaked in a full-strength, pH-adjusted nutrient solution such as Formula One. The blocks, prior to use, should be thoroughly soaked in nutrient solution. Place the small cube inside the hole in the larger block. To discourage the growth of algae, cut a 3” square piece of white plastic with a slit for the stem and place on top of the block. The plastic should not touch the stem. When the plant is large enough to completely shade the rockwool, the plastic can be removed.

When roots have penetrated the blocks, it's time to place the blocks on the plastic wrapped slabs. Space the slabs to achieve your desired plant density. This plant density will vary depending on varieties and techniques used. There is a top and bottom to every slab. On slabs with a seam running down the length, there is a small puncture hole accompanying the seam, which is always facing up. To prepare the slab for growth, cut a flap in the plastic where each plant is to be placed. The flap should be large enough so that when it is folded back, there is enough room top your growing block to make full contact with the rockwool of the slab. Fill the slab with the nutrient solution until the plastic sleeve of the slab bulges with excess solution. Allow the slab to soak for up to 24 hours. Alter soaking, the slabs should slope 2 degrees towards the drainage area. Cut a 2" drainage slit at the base of the slab at the end closest to your trays drainage hole. slits can also be made along the length of the slab base, if desired. Place the growing blocks in the cut flaps on top of the slab. If using drip emitters, keep then on top of the blocks, making sure that the dripping solution does not touch the plant's stem.

With automatically-timed waterings of rockwool, it is advisable to do your first light watering one hour before sun up to charge the slab. Water frequently until the plant’s roots have established themselves from the block securely into the slab. Once the plants have secured themselves to the slab, you can begin watering when the slabs dry to 60% of their saturated weight. Hand watering also gives good results with only one watering a day; just be sure that the slab is large enough so that it doesn't go below 60% saturated weight between waterings. We suggest flushing the slabs with 100% excess nutrient solution at least once every 2 weeks.

THE 4 MAJOR RULES OF WATERING ROCKWOOL ARE:

1. Always maintain a pH of approximately 5.8 in the nutrient solution.
2. Maintain a full-strength nutrient solution during every watering.
3. About 20 to 30% of the total solution applied during any given day should leach out the bottom of the rockwool. Flush the rockwool 100% with fresh nutrient solution, every two weeks.
4. Never drench rockwool with a fungicide or insecticide at 100% of recommended label rate. Use only 15 to 20°/'o of the recommended on the label. Contact us for further information.