September 5, 2012
Propagating Hydrangeas From Cuttings
Last week, there was the most beautiful arrangement of giant clear blue mophead hydrangeas adorning the reception area of my offices in the Starrett Lehigh building in Manhattan. Of course, seeing such magnificent blooms, I wanted to grow that particular variety of hydrangea in my garden, but I wasn’t sure of its name. So, rather than guess and perhaps order the wrong plant, I decided to bring the stems home and have Ryan McCallister, my gardener, propagate new plants from the cuttings. It’s an interesting and rather simple process and also very gratifying.
1 These are the hydrangea stems that I brought home for Ryan to root. Some are quite long.
2 The stems were cut cleanly, at an angle, and kept moist inside damp paper toweling.
3 A stem for hydrangea propagation should be at least 4 inches long and new growth. A new growth stem is a lighter green in color than old growth, which tends to be on the woody side.
4 Ryan snipped the long stems, separating them just above a leaf node, where new leaves will hopefully form.
5 The shorter stem cuttings are the right length for rooting.
6 Empty reusable pots and trays are stored neatly in the greenhouse basement. These pots are washed thoroughly after each use.
7 Ryan began mixing the rooting medium, a blend of equal parts perlite, vermiculite, sand, and a bit of potting medium. This white substance is perlite, a volcanic mineral that improves aeration and drainage and traps moisture, making it available to plant roots.
8 This is vermiculite, a lightweight mineral that improves soil aeration and moisture retention.
9 The rooting medium all nicely blended
10 Ryan filled the pots with the mixture.
11 He then place the filled pots in the trays.
12 And gave the medium a nice drink of water
13 Next, Ryan poked holes in the rooting medium using a small wooden dibber, or dibble.
14 Although not absolutely necessary, the use of a rooting hormone, which acts as a root stimulant, will increase the chances of successful propagation.
15 Ryan sprinkled a bit of the hormone into another container.
16 He then dipped the bottom part of the cutting into the hormone.
17 Just a bit on the end does the trick.
18 The cuttings were then placed into the holes.
19 And the soil firmed around the cuttings
20 Any large leaves were snipped off, focusing attention on the formation of roots.
21 Ryan continued snipping the other long stems, dipped them in the hormone, and planted them in the pots.
22 In all, we have a potential total of 36 new hydrangea plants. In a couple of weeks, Ryan will look very gently to see if they are indeed forming roots and if so, we'll have to figure out where to plant them!