Home / How to propagate geranium / The best way to propagate geraniums

The best way to propagate geraniums

If you have ever wondered what is the best way to propagate geraniums, then this article is for you.

 

Overview:

  • This summer I started an experiment to determine what was the best way to propagate geranium plants (AKA pelargonium species).
  • The results were surprising and they will definitely change the way I do things in the future.
  • If you want to skip to the punchline regarding the best propagation method, just read the only underlined sentence found toward the end of this article.  However, the “Materials & Methods section of this article is basically a road map to successfully do it yourself.  Yea, a way to get more free plants!

 

Why bother you ask?

Well… a little while back I tried to research the best way to propagate geranium plants.  As it turns out, there are a lot of different techniques, and everyone seems to think that their method is the best.  So, this left me in a bit of a dilemma; how do I move forward with this conflicting information?  Besides, I thought to myself, how can there be 20 BEST ways to do something?  Another interesting point is that I have not found any “proof” to support that one particular propagation technique is scientifically better than another person’s “best” method.

As a result, I set up an experiment to answer the question for myself.  I tested the top few methods on my list and I also added another crazy method in there just for fun.  I did my best to control the experiment for outside variables so the results could be as clean as possible.  For example, I used the same soil, growing conditions, and the same mother plant for all of the cuttings.

 

Materials & Methods:

Plant preparation:

  • On July 12, 2014, I collected a small pile of cuttings from a single geranium plant (Ivy-leaved geranium: Pelargonium peltatum).
  • Multiple softwood cuttings were then all clipped to about the same length (about 5 in or 13 cm long).
  • Old woody stems were discarded because of lower expected germination rate with woody stems.
  • The bottom leaves were removed from all of the cuttings.  This left only a few leaves at the top of each 5 inch long cutting.
Day 1. Clump of cuttings saved from the big compost heap in the sky

Clump of clippings saved from the big compost heap in the sky (July 12, 2014).

geranium exp day 1...7.12.14 with cuttings

Multiple softwood geranium cuttings ready to put into the containers.

 

Soil preparation:

  • The soil mixture that I used was native sandy soil mixed with about an equal amount of grow mulch.
  • I thoroughly mixed up the soil in a large bin separately, and then added equal amounts of the soil-mix into each of the five containers.
  • In each container, I made 5 depressions in the soil for the cuttings to be placed into.  The pattern for the 5 depressions was the same that you would see on a dice (die).
  • The depressions in the soil for the cuttings were about 1 inch deep.  These soil depressions were made with the non-writing end of an old clean sharpie pen.
geranium on day 1

Geranium cuttings placed in the pre-made soil depressions. Picture taken just before the soil was pushed in around the cuttings.  Day 1 of the experiment.

 

Different propagation methods tested:

The main variable between the five propagation methods tested was the material that was added to the soil-end of the cutting.  The five arms of the experiment are as follows.

  1. Control (nothing was added to the end of the cutting)
  2. Root hormone (the powdered stuff you can get at the store)
  3. Honey (apparently honey is beneficial because of it’s antibacterial properties)
  4. Tanglefoot  (yes it was a crazy-unsupported idea)
  5. Clean water (the cuttings were just placed into regular old water with no additional prep)

 

All containers got the same treatment:

  • The specific material being tested (honey, root hormone, Tanglefoot) was added to the soil-end of the plant-cutting.
  • Five cuttings (for each separate arm of the experiment) were added to the pre-made soil depressions in each container.
  • Then the soil was pushed around the cuttings and watered in (obviously except for the last option where the 5 cuttings were just put in water).
  • The containers were all placed in the same physical location in the yard. This location was was partly shady.
  • Every few weeks, I moved the containers around in relationship to each other to be extra sure they were all getting the same treatment.

 

Result journal:

July 26, 2014

  • All of the cuttings looked about the same.
  • All cuttings appear to be struggling a bit and leaves were turning yellow-ish.
  • Perhaps this early yellowing reflects the changes from diverting energy into the roots, and/or I am over watering.
geranium exp 7.26.14

Early on, all of the cuttings were looking a bit sad. Top row from left to right: (water, Tanglefoot, root hormone. Bottom row from left to right: (Just soil and no plants waiting foe water experiment to root, control, honey) Pic taken July 26, 2014

 

August:

  • No idea where I was.
  • I must have been too busy to take pictures or keep notes-sorry.

 

September 4, 2014

The results below are ordered in relationship to the propagation success:

  1. Control: 4/5 cuttings survived and total/overall growth for this technique was the most robust.
  2. Honey: 4/5 cuttings survived and total vegetative growth lagging behind the control.
  3. Root hormone: 3/5 cuttings survived
  4. Water: 2.5/5 cuttings survived (I say 2.5 because one of the remaining cuttings still has some leaves on it but the stem is rotting. Another cutting is not rotting but has no roots. Only one cutting has roots.
  5. Tanglefoot: 1/5 cuttings survived.
Geranium exp on 9.4.14

Geranium cutting progress on September 4, 2014

 

 September 18, 2014 

The results below are ordered in relationship to the propagation success:

  1. Control: 4/5 cuttings survived and total growth was the most robust. Cuttings are even flowering!
  2. Honey: 4/5 cuttings survived and total vegetative growth lagging behind the control.
  3. Root hormone: 2/5 cuttings survived (Another cutting dead from Sep 4).
  4. Water: 2/5 cuttings survived.
  5. Tanglefoot: 1/5 cuttings survived.
Geranium propagation experiment results on September 18, 2014

Geranium propagation experiment results on September 18, 2014

October:

  • Sorry no pics.
  • However, the results for October are about the same as Sept 18 except that all of the cuttings in the water part of the experiment are now dead.

 

Conclusion:

  1. In this experiment, the simple control method did the best!  Just stick the cutting in soil and keep moist. This was actually a big surprise for me.
  2. The honey experiment option was close behind at second best.  The honey had the same number of cuttings surviving, but the growth rate was not as robust as the control method.
  3. In this experiment, the use of root hormone was no more than an added expense that actually lead to worse results (when compared to the control method).
  4. The Tanglefoot option was a disaster and is not recommended for this indication.  Only one sickly looking cutting survived in this arm of the experiment. (Note, this is not the intended use of Tanglefoot which I think is an awesome product for sap-sucking bug control).
  5. Rooting in water was not very successful at all.  Only one of the five cuttings ever rooted and it eventually died as well.  In fairness, I should have transferred the rooted cutting into soil earlier.  However, even if I did – and it survived, it still would mean that only 1 out of 5 in the water propagation method cuttings could have lived.

 

Some additional interesting info about Geraniums:

  • Geraniums (pelargonium species) are a beautiful and hassle free option for drought tolerant landscaping in Southern California.
  • Geraniums are also in the elite category of gopher resistant plants. However, they but not totally gopher proof.  For more details on that subject, see my earlier article on Gopher Resistant Plants: Truth & Fiction.
  • They are evergreen perennials that are both drought and heat tolerant. However, they can only tolerate minor frosts.
  • Geraniums are indigenous to Southern Africa

About Thomas Osborne, MD

Dr. Osborne is a Harvard trained Radiologist and Neuroradiologist who loves to share his insight about medicine and gardening.

11 comments

  1. Very nice article. Very informative. Thanks
    Sandra

  2. Real Science! Totally refreshing. Thanks so much. I will use the control, no-fuss method.

    Susan

  3. Thanks very much for this. It’s great to see the proof that the easiest, lowest-cost method produces the best results.

    • Thomas Osborne, MD

      Thank you for the note.
      You are very welcome Jan.
      I totally agree with you, its awesome to see when the best method are the cheapest.
      Tom

  4. Another way to do this that is not so extensive is as follows!

    Materials Needed:
    -6- 4 1/2″ pots (depending on how many cuttings you take) This is for 6 cuttings.
    -1 bottle of Rooting Hormone Powder 0.08%
    -Soil Mixture: Metro Mix (Sungrow is what I use), Organic Compost (Happygrow or Redearth is what I use)
    -Water
    -Sharp Pair of Snips (No pruners because it makes the wrong type of cut)

    Instructions:

    -Mix soil types at a 50/50 ratio and fill pots not packing them.
    -Use a pencil to make a hole in the center of each pot to place your cuttings in.
    -Get your Rooting Powder ready (I use the lid and pour some powder in it so not to waste).
    -Water the soil not to saturate but to moisten.
    -Get your snips and take cuttings in the following way: Count 5-6 leaves from top down and make cut using the snips (a straight cut) right above the 7th leaf (Node).
    -Remove one leaf after the first cut using the snips.
    -Dip the cut end in the Rooting Powder and place in the soil where the hole was created.
    -Use the dice method (the face of 5 on a die) to pack the soil around the cutting.
    -Water once more but not to saturate.

    * Once all cuttings have been watered it’s important to put them in a sunny location. The ideal place would be in a grow house or hot house (high humidity, good air circulation, full sun). If you don’t have one you can make your own out of a thick plastic or buy a small one ( known as frost protectors for the garden).
    * Remember to keep soil moist at all times but not saturated!
    * In about 2-3 weeks they will be ready to transplant in to a different container of your choice. Using the same soil mixture would be ideal because it drains well.
    * Adding ‘Osmacote Non-burning fertilizer’ 1 Tablespoon per Gallon size of Container will help the roots to become established quicker and cause your plant to thrive.
    *Make sure to water in the fertilizer any time it is used ( bi-annually )!

    Good Luck and Have Fun!

    • A suggestion:

      -Try the “Citronella Geranium” to help repel those Mosquitos this year. You can find them at your locally owned nurseries they are usually kept with the Herbs or Lemon Verbena.

  5. Thanks for sharing this information – which was also a reminder to me to do the research first. I dropped a handful of geranium cuttings into water yesterday – and this morning had a nagging feeling there might be a more effective way to coax them into rooting. So this evening I plan to move them into a slightly moist potting mix and follow your basic guidelines. Your info is appreciated. I do have one question that calls on both your medical and gardening expertise. Somewhere in the past, I recall reading that plants can benefit from B Vitamins — producing stronger root systems, larger plants and greater yields of flowers/fruit/vegetables. I have no idea which B Vitamins, and no idea how they would be applied. (I’m hesitant to drop a couple of Flintstone chewable vitamins into my flower pots.) Just curious whether you might have any expertise with or knowledge of this?

    • Thomas Osborne, MD

      Hey Jim
      Great question.
      I have heard similar things… somewhere.
      Really dont know how true that is though… I have never experimented with plants + B Vitamins myself.

Leave a Reply

Your email address will not be published.

Scroll To Top