BASICS ON HYDROPONIC CLONING

BASIC CLONING
Many people ask us the procedures involved in producing cuttings for propagation. All of the articles they have read are too involved, too detailed and end up sounding like a test on brain surgery.
There are many methods for taking cuttings, but if you adhere to the basics, growing cuttings is a simple, efficient way of starting new plants. If, after you have successfully mastered these basics, you wish to experiment with a few cuttings at a time until you know the method works well.
Choose a healthy, robust plant for your cutting stock, or mother plant. These cutting stock plants should have characteristics which you desire to preserve, as all cuttings from it will be genetically the same as the mother.
Although cuttings from your plants will root, remember they are chronologically the same age as the cutting stock plant from which they were taken. It is usually desirable to make cuttings from a more mature plant as they are already beginning to produce hormones necessary for flowering and thus fruiting.
For example, cuttings from a flowering tomato plant will begin to produce fruit almost immediately. Tomato plants, started from seed will take at least six weeks. However, taking cuts from a plant that is far into flowering is not advisable, some will grown and some won’t.
Materials

  • A036/40 Rockwool seed cubes or DU4 (no hole) propagation blocks.
  • Very sharp scissors
  • Standard 11 x 21” flat (no holes) with seed cells and humidity dome
  • Rooting solution (liquid or gel) containing INDOLE-3 BUTRIC ACID or INDOLE-3 ACETIC ACID
  • Olivia’s Solution
  • Materials for PH control
  • Captan fungicide
  • Clorix bleach or Physan “20”

First mix a solution with which to wet the Rockwool seed cubes or prop blocks.
Olivia’s Solution is a nutrient for cuttings. It also contains rooting hormones and essential trace elements. Mix at a rate of 6 oz. per gallon of water. Distilled water is best, but tap water will work fine unless you are using hard well water.
Green Thumb Hydroponic Supplies sells both liquid and gel rooting solutions. The gel (Clonex) adheres to the stem and for most plants the results are excellent. Some users report that it is too strong for some varieties, in which case the liquid is recommended. If the liquid rooting solutions is used, add 1 teaspoon per gallon to the Olivia’s mixture. Adjust PH t9o 6.0.
This solution may be applied by hand watering or automatically (e.g., flood table).
The growing tips we desire may be cut from the top or the side branches of the mother. Looking at the mother plant, select an active growing tip to three sets of sun leaves and 2 to 4 inches in total length.
Whether or not to trim off the third set of sun leaves is dependent on the total length of the cutting. If the cutting is 2 to 3 inches keep the third set of leaves. If it is longer than three inches remove them. Trimming should be done while the clone is still attached to the mother.
If liquid cutting solution is used pour ½” of solution into a cup or similar container. Make the cut between the third and fourth internode. Using the dull side of the scissors gently scrape the tissue around the part of the stem (1/2”) which will be buried in the Rockwool. This allows the stem to absorb easier and roots will form all along the disturbed tissue.
Now submerge the end of the cutting in the liquid cutting solution. While submerged, use the scissors to make a thin final cut, off the tip, to remove any possible air bubble trapped in the end. Allow to remain in the solution 1 or 2 minutes.
If using a gel, make the final cut and immediately place in the gel.
Although Rockwool seed cubes are manufactured with a pre-punched hole for cuttings they are sometimes too loose around the stem. Using an ice pick, which has been dipped in the Clorox, make your own hole off to one side of the prepunched hole. Use the same procedure if using DU4 blocks.
Wash the flat seed cell and humidity dome with a solution of 1 oz. Clorox or “Physan 20” per gallon of water to sterilize them.
Soak the Rockwool cubes or prop blocks with the prepared Olivia’s solution and allow to drain. Place in the seed cells and then the flat.
Dampening off is a fungal disease prevalent in Florida. Excess humidity promotes the growth of the fungus, causing the stem to be mushy and rot at the base. To prevent dampening off, mix a solution of Captan fungicide and water. Use this to spray the top of the wet Rockwool.
You can now transfer the cutting from the cutting solution to the Rockwool. Do this as quickly as possible. If using the gel, scrape the excess gel off on the side of the bottle before transfer.
Care of the Cuttings
There are several factors to consider in caring for the cuttings. Humidity, temperature, C02 levels, feeding and lighting must be controlled to obtain healthy, robust cuttings.
Balancing humidity causes the most problems for growers. Too low humidity causes loss of moisture, wilting and death. Excess humidity encourages fungal diseases such as dampening off. In Florida, with its high humidity, there is a lot of fungus spores in the air. Spray the cuttings and the surface of the Rockwool weekly with Captan to control fungus growth during rooting.
Cuttings require high humidity during rooting. As they lack roots, moisture and nutrients can only be absorbed through the stem and leaves. Moisture is lost through the leaves due to transpiration (breathing).
Humidity domes must be used to control the rate of transpiration
Also, misting of the leaves is a good way to increase water intake. But mist only once a day and only if wilting is evident.
After placing the cuttings in the Rockwool cubes, mist them lightly with water and cover dome. Do not remove the dome for three days unless a problem is evident.
After three days begin to feed the cuttings with the Olivia’s solution once per day. Be sure to apply enough solution to wash through the cubes. This action replaces nutrients and adjusts the PH in the Rockwool.
The Rockwool must be permitted to drain. Do no allow the cubes to stand in the solution. If you are hand watering, a hole may be cut in the corner of the flat to catch the runoff in an empty container. The PH of the runoff may be adjusted and the solution reused.
This is also the time to allow some air to the cuttings. Once watering is begun, open the vent in the humidity dome. If no vent is present, place something under the side of the dome to allow some air flow.
Ideal temperature is 752~ Lower temperatures will slow rooting, higher temperature will promote fungus growth and increase moisture loss through transpiration.
If possible, increase the C02 level. This increase will speed rooting as well as growth. At least, make sure fresh air is available to the cuttings.
Lighting
For small scale production of cuttings fluorescent lights work fine, Cuttings do not need as much light in the rooting stage as in the later stages.
A 4’ fluorescent fixture will support two 21” x 11” flats. Place the lights to within 2” of the top of the plants for maximum lumens.
Green Thumb Hydroponic Supplies recommends Vitalite Power Twist for maximum lumens and proper daylight spectrum (5500aK). Vitalite also carries a 3 year guarantee.
For larger areas, metal halide lighting is best. Care must be taken to keep the metal halide far enough from the cuttings to prevent drying them out. Some people place cutting trays around the mother plant to take advantage of the existing metal halide lights as well as the C02 enriched atmosphere.
The lighting period should be from 18 to 24 hours per day. Rooting is faster under 24 hours of light.
Feeding
After beginning to feed at three days, continue the once a day feeding with the Olivia’s solution until roots have formed. Under proper conditions, this usually takes 10 to 14 days. If using seed cubes, the roots may be seen growing out of the sides and bottom. IfDU4 propagation blocks are used, gently pull the Rockwool away from the stem, checking for root formation.
Generally, the dome may be removed after seven days. As a test, remove the dome and check the cuttings periodically over several hours. If the plants are wilting, mist them and replace the dome. Try again in a few days.
Once the roots have come through the seed cubes, the cubes must be transferred to propagation blocks. To avoid this step, some people use a no-hole propagation block at the beginning.
Normally at this point, there will be some yellowing of the lower leaves. This is a symptom of nitrogen deficiency and it’s time to change nutrient solutions. Now use a half-strength, PH-adjusted grow formula. Taking samples from the Rockwool to test for PH and PPM concentrations should be started. Refer to Green Thumb Hydroponic Supplies’ handout “Rockwool Guidelines” for information.
Now the cuttings have become small plants. They may be held in the Rockwool blocks and vegitated until planting time. The plants can use more light now that the roots are established. Most people using H.I.D. lights will plant at a maximum of 6 inches in height, but they may be held longer. If, at planting time, you find long roots exiting from the bottom of the blocks, cut these back to 1/2” in length.
Once you have established a successful pattern of cloning, do it the same each time. With a little practice you will find cloning simple and fun.

 

BASIC CLONING
Many people ask us the procedures involved in producing cuttings for propagation. All of the articles they have read are too involved, too detailed and end up sounding like a test on brain surgery.
There are many methods for taking cuttings, but if you adhere to the basics, growing cuttings is a simple, efficient way of starting new plants. If, after you have successfully mastered these basics, you wish to experiment with a few cuttings at a time until you know the method works well.
Choose a healthy, robust plant for your cutting stock, or mother plant. These cutting stock plants should have characteristics which you desire to preserve, as all cuttings from it will be genetically the same as the mother.
Although cuttings from your plants will root, remember they are chronologically the same age as the cutting stock plant from which they were taken. It is usually desirable to make cuttings from a more mature plant as they are already beginning to produce hormones necessary for flowering and thus fruiting.
For example, cuttings from a flowering tomato plant will begin to produce fruit almost immediately. Tomato plants, started from seed will take at least six weeks. However, taking cuts from a plant that is far into flowering is not advisable, some will grown and some won’t.
Materials

  • A036/40 Rockwool seed cubes or DU4 (no hole) propagation blocks.
  • Very sharp scissors
  • Standard 11 x 21” flat (no holes) with seed cells and humidity dome
  • Rooting solution (liquid or gel) containing INDOLE-3 BUTRIC ACID or INDOLE-3 ACETIC ACID
  • Olivia’s Solution
  • Materials for PH control
  • Captan fungicide
  • Clorix bleach or Physan “20”

First mix a solution with which to wet the Rockwool seed cubes or prop blocks.
Olivia’s Solution is a nutrient for cuttings. It also contains rooting hormones and essential trace elements. Mix at a rate of 6 oz. per gallon of water. Distilled water is best, but tap water will work fine unless you are using hard well water.
Green Thumb Hydroponic Supplies sells both liquid and gel rooting solutions. The gel (Clonex) adheres to the stem and for most plants the results are excellent. Some users report that it is too strong for some varieties, in which case the liquid is recommended. If the liquid rooting solutions is used, add 1 teaspoon per gallon to the Olivia’s mixture. Adjust PH t9o 6.0.
This solution may be applied by hand watering or automatically (e.g., flood table).
The growing tips we desire may be cut from the top or the side branches of the mother. Looking at the mother plant, select an active growing tip to three sets of sun leaves and 2 to 4 inches in total length.
Whether or not to trim off the third set of sun leaves is dependent on the total length of the cutting. If the cutting is 2 to 3 inches keep the third set of leaves. If it is longer than three inches remove them. Trimming should be done while the clone is still attached to the mother.
If liquid cutting solution is used pour ½” of solution into a cup or similar container. Make the cut between the third and fourth internode. Using the dull side of the scissors gently scrape the tissue around the part of the stem (1/2”) which will be buried in the Rockwool. This allows the stem to absorb easier and roots will form all along the disturbed tissue.
Now submerge the end of the cutting in the liquid cutting solution. While submerged, use the scissors to make a thin final cut, off the tip, to remove any possible air bubble trapped in the end. Allow to remain in the solution 1 or 2 minutes.
If using a gel, make the final cut and immediately place in the gel.
Although Rockwool seed cubes are manufactured with a pre-punched hole for cuttings they are sometimes too loose around the stem. Using an ice pick, which has been dipped in the Clorox, make your own hole off to one side of the prepunched hole. Use the same procedure if using DU4 blocks.
Wash the flat seed cell and humidity dome with a solution of 1 oz. Clorox or “Physan 20” per gallon of water to sterilize them.
Soak the Rockwool cubes or prop blocks with the prepared Olivia’s solution and allow to drain. Place in the seed cells and then the flat.
Dampening off is a fungal disease prevalent in Florida. Excess humidity promotes the growth of the fungus, causing the stem to be mushy and rot at the base. To prevent dampening off, mix a solution of Captan fungicide and water. Use this to spray the top of the wet Rockwool.
You can now transfer the cutting from the cutting solution to the Rockwool. Do this as quickly as possible. If using the gel, scrape the excess gel off on the side of the bottle before transfer.
Care of the Cuttings
There are several factors to consider in caring for the cuttings. Humidity, temperature, C02 levels, feeding and lighting must be controlled to obtain healthy, robust cuttings.
Balancing humidity causes the most problems for growers. Too low humidity causes loss of moisture, wilting and death. Excess humidity encourages fungal diseases such as dampening off. In Florida, with its high humidity, there is a lot of fungus spores in the air. Spray the cuttings and the surface of the Rockwool weekly with Captan to control fungus growth during rooting.
Cuttings require high humidity during rooting. As they lack roots, moisture and nutrients can only be absorbed through the stem and leaves. Moisture is lost through the leaves due to transpiration (breathing).
Humidity domes must be used to control the rate of transpiration
Also, misting of the leaves is a good way to increase water intake. But mist only once a day and only if wilting is evident.
After placing the cuttings in the Rockwool cubes, mist them lightly with water and cover dome. Do not remove the dome for three days unless a problem is evident.
After three days begin to feed the cuttings with the Olivia’s solution once per day. Be sure to apply enough solution to wash through the cubes. This action replaces nutrients and adjusts the PH in the Rockwool.
The Rockwool must be permitted to drain. Do no allow the cubes to stand in the solution. If you are hand watering, a hole may be cut in the corner of the flat to catch the runoff in an empty container. The PH of the runoff may be adjusted and the solution reused.
This is also the time to allow some air to the cuttings. Once watering is begun, open the vent in the humidity dome. If no vent is present, place something under the side of the dome to allow some air flow.
Ideal temperature is 752~ Lower temperatures will slow rooting, higher temperature will promote fungus growth and increase moisture loss through transpiration.
If possible, increase the C02 level. This increase will speed rooting as well as growth. At least, make sure fresh air is available to the cuttings.
Lighting
For small scale production of cuttings fluorescent lights work fine, Cuttings do not need as much light in the rooting stage as in the later stages.
A 4’ fluorescent fixture will support two 21” x 11” flats. Place the lights to within 2” of the top of the plants for maximum lumens.
Green Thumb Hydroponic Supplies recommends Vitalite Power Twist for maximum lumens and proper daylight spectrum (5500aK). Vitalite also carries a 3 year guarantee.
For larger areas, metal halide lighting is best. Care must be taken to keep the metal halide far enough from the cuttings to prevent drying them out. Some people place cutting trays around the mother plant to take advantage of the existing metal halide lights as well as the C02 enriched atmosphere.
The lighting period should be from 18 to 24 hours per day. Rooting is faster under 24 hours of light.
Feeding
After beginning to feed at three days, continue the once a day feeding with the Olivia’s solution until roots have formed. Under proper conditions, this usually takes 10 to 14 days. If using seed cubes, the roots may be seen growing out of the sides and bottom. IfDU4 propagation blocks are used, gently pull the Rockwool away from the stem, checking for root formation.
Generally, the dome may be removed after seven days. As a test, remove the dome and check the cuttings periodically over several hours. If the plants are wilting, mist them and replace the dome. Try again in a few days.
Once the roots have come through the seed cubes, the cubes must be transferred to propagation blocks. To avoid this step, some people use a no-hole propagation block at the beginning.
Normally at this point, there will be some yellowing of the lower leaves. This is a symptom of nitrogen deficiency and it’s time to change nutrient solutions. Now use a half-strength, PH-adjusted grow formula. Taking samples from the Rockwool to test for PH and PPM concentrations should be started. Refer to Green Thumb Hydroponic Supplies’ handout “Rockwool Guidelines” for information.
Now the cuttings have become small plants. They may be held in the Rockwool blocks and vegitated until planting time. The plants can use more light now that the roots are established. Most people using H.I.D. lights will plant at a maximum of 6 inches in height, but they may be held longer. If, at planting time, you find long roots exiting from the bottom of the blocks, cut these back to 1/2” in length.
Once you have established a successful pattern of cloning, do it the same each time. With a little practice you will find cloning simple and fun.

 

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