Hydrangea Macrophylla Propagation

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Late July 2016: Hydrangea Macrophylla in original location in full bloom

 

This beautiful Hydrangea Macrophylla was in full bloom in August 2016.  It was a well established plant which had been in the garden for over 15 years.  It’s pink and purple appearance made me think that it could possible produce blue flowers if the pH of the soil was right.  Despite its incredible beauty, the owner wanted this removed to make way for another garden project.  The roots were extremely well established and this made it essentially impossible to remove the plant with roots included.  Instead of taking the root ball, we took hardwood cuttings as close to the roots as possible.

 

All of the tutorials on the internet recommend taking young, green cuttings rather than old wood.  Unsure if hardwood cuttings would successfully root, we progressed with the experiment anyway.  This was already a risk as the plant was well established in the ground and I was attempting to propagate these on a 5th floor balcony in central London!  I knew this entire process would be quite a shock to the plants, so I wanted to maximise my chances of success.  Two different methods were used:

  1. Dip in rooting hormone and plant cuttings straight into soil
  2. Soak cuttings in water for two days before dipping into rooting hormone and potting into soil

I found altogether there didn’t seem to be much of a difference between each of the methods, but I think the rooting hormone really helped, especially because the cutting were so old.  I bought my rooting hormone on Amazon, and I have been using it on other propagation projects since.

14th August 2016

14th August 2016: Fresh cuttings soaking in water

 

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14th August 2016: Planting directly into soil in progress

 

14th August 2016:  Planting complete – All advice on the internet suggested that I cut back the majority of flowers and the leaves straight away to minimise stress on the cuttings straight away, but they were too beautiful I could not bring myself to do it.

20th August 2016

Throughout the week I watered the pots every day or so, depending on if the soil looked like it was drying out.  I was DESPERATE to see if any progress was happening underneath the soil but knew the best chance of survival was to leave it alone.  And pray.  I knew this was going to be an exercise in patience as all of my research said that no “above ground” progress would be seen for 6 months, since we were going into Autumn.  I had no idea that actually I would be seeing my first leaf sprouts within a month!

20th August 2016: 6 days after planting, branches were pruned, I cut off most of the leaves and flowers which were dying.

 

20th August 2016: Here you can see the tubs I used to plant the cuttings, holes were drilled into the bottom to provide drainage

25th September 2016

Just a month later I saw the first signs of a sprout of leaves, and I was shocked!  These small leaves popped up in all of the plants and grew very slowly.  One thing I noticed is that they tended to appear along the edges of the pots, rather than the cuttings which were in the middle of the pot.  Perhaps they thrived with the added protection from the elements?

The second surprise I had was that these baby leaves didn’t drop over winter.  They continued growing very slowly but steadily and I continued to water them when the soil looked like it was drying out.  During winter I watered them about once a week.

 

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25th September 2016: New leaf growth

 

January 2017

Unfortunately I don’t have any photos of this project. The leaves started to show some more growth in late January, so I decided to carefully go through the cuttings and get rid of the dud cuttings.  I didn’t really touch the ones which already have leaves because I knew they were successful so far. At this point it seemed to me that there was approximately a 30-40% success rate with the hardwood cuttings, which I was happy with.  I was quite surprised with what I found once I inspected underneath the soil.   I focused on the stems which showed no sign of new growth, to throw them out if they were dead.  Interestingly, there were small roots growing on almost all of them.  The new roots were very small, and perhaps won’t be successful, but I decided to leave them in there for the growing season to give them a chance.  In this process I threw out perhaps 20% of the cuttings, meaning that there was potential growth in more like 70-80% of the cuttings!

I added soil mixed with perlite onto the pots and about a week later, I watered all of the cuttings with a mixture of water and ‘worm tea’.  Since that watering, the leaves have started growing like CRAZY!

March 2016

As it is the beginning of spring, all of my hydrangeas are sprouting new leaves every day. I think the worm tea really helped them as well.

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20th March 2017: New leaves growing each day

 

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20th March 2017: Cuttings which were transplanted into another pot are also showing new growth every day, although leaves at the back are wilting slightly, I think this is due to recent unusually windy weather

 

20th March 2017: More strong growth coming from very old hardwood cuttings

 

20th March 2017: Hydrangea propagation from hardwood results after 6 months, as you can see, the old wood cuttings have been pruned right back

April 2017

The leaves are continuing to grow rapidly, however the leaves in one of the pots are appearing quite yellow rather than the usual green colour.  After some research online, it seems that yellowing leaves of Hydrangeas is a sign of nitrogen deficiency.  A solution for this is to add a high nitrogen fertiliser.  I purchased this fertiliser and added to the plant, updates on photos to follow to see if it helps.

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2nd April 2017: Side view showing strong stalk growth and leaves,  the leaves are quite yellow, however it is only appearing slightly yellow in this picture

 

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2nd April 2017: Leaves appearing more yellow than green, high nitrogen fertiliser was added to help the growth of the leaves.  Hydrangea will not flower this year as it was only propagated in Autumn 2016, so flower buds did not have opportunity to develop

To see the second part of this propagation, click here

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