Hydrangea Propagation: experienced advice required.

I've read a tidbit or three that these can be propagated merely by putting them into water. Now, to my mind, that seems like an easy-peasy way to make more plants. And, I would really like some more plants from the 3 I currently have!

However, I've also read a cautionary tale that the roots formed via the glass jar/water method are not "real" roots and therefore, destined to failure

Anyone have a beginner/idiot-proof/tried and tested method of propagating hydrangeas? I'd really like to get some cuttings started, ready for next Spring (as long as it isn't too late to do it now?)

Thank you

 

I get as near to 100%, as makes no odds, strike on Hydrangeas.

I don't believe in rooting in water (for anything that will root easily in water) as I find that getting them to transition to soil/compost results in some failures (as you have described). I'm sure some folk have no trouble, but they probably have "green fingers" in the sense that they know what to do, and when to do it ... whereas what you are looking for is a failsafe method.

I think that things that will root "just in water" will root very easily anyway, so its a good indication that they should be "easy".

Here's what I would suggest:

Prepare the pot(s) first. Mix multi purpose compost 50:50 with perlite if you have it, otherwise sharp sand. If you don't have either ask and I'll dream up an alternative! (for example seed sowing compost would probably do, its very sandy ...)

I would sieve it through 3/8th" mesh - something reasonably fine - to get rid of all course material, and I would rub the mix through my hands a) to get it even and b) to get the multi purpose as fine as possible (the perlite / sand will then provide drainage and keep it open). We need the compost to be in good contact with the cuttings, that won't happen if it is coarse.

I use shallow pots (so called "pans") about 4" - 6" in diameter.

Get the compost moist. If you squeeze it into a sausage in your hand it should cling together, but if you attempt to break it then it should break apart a) cleanly and b) easily. If it will not hold together as a sausage it is not wet enough, if when you squeeze it water oozes out its too wet (add more compost mix), and ditto if it doesn't break apart cleanly.

Fill the pots to the brim and then gently firm them - don't ram them down at this stage. Filling to the brim, initially, will mean that once the cuttings are in, and firmed, that the compost level will be close to the "lip" depth.

Right: Now you need your cuttings.

I suggest you perform the whole of this exercise on one trial piece of suitable cutting material. That will tell you whether the bit you have selected is long / big enough, or not, and then you will know how big the rest need to be. If you cut them all off the Mother Plant initially, and then find they are too short, then you will need the "putting on machine" so the Following is the procedure, but try with one piece first, then with a whole batch.

Cut off some suitable pieces, best are non-flowering shoots. They need to be at least 4" long, 6" or maybe 9" is the max. Cut them off just above a leaf pair (which will encourage the buds there to break and make a bushy mother plant ). Put them immediately into a plastic bag.

When you have finished gathering material bring them back to the house where you will prepare them. Don't do this in direct sun, the plants will wilt.

You need a sharp knife (I use a scalpel, but on the telly they always use a penknife. A sharp kitchen knife will do, if its not too precious!). Cut immediately below the lowest leaf pair (so you will be throwing away the bottom bit of stalk).

Gently remove the bottom pair of leaves. They should snap off cleanly, but if not cut them off neatly tight to the main stem. If the buds in the leaf axil have started to open, or are very fat, I would break them off too, if they are tiny I leave them on).

Do the same for the next leaf pair up. If the leaf pairs are very close together you might remove the third leaf pair too. No exact science here, I find that if I bury several leaf-joints then often they all produce roots, so 3 x leaf pairs buried results in a cutting with a bigger root system when I pot on. But your pot has finite depth

Your ideal cutting will then have 2 full leaf pairs above that, and perhaps a tiny leaf pair emerging above that. You might get away with 1 full leaf pair, but I cuttings with so little "top" tend to be fragile

The leaves on Hydrangeas are big, so for all the leaves left on the cutting (unless they are tiny) cut them in half - so you remove the end half of the leaf. This reduces the leaf area (obviously!) and the plant doesn't have to suck up as much water to support the full leaf area.

Get a pencil and push it into the compost ready to make a suitable hole (do this near the edge of the pot) then dip the cutting in hormone rooting powder and knock off all the excess.

(If you don't have any Hormone Rooting Compound I wouldn't worry for Hydrangeas, but worth having some on the shelf for the future; personally I prefer "Clonex" which is a gel rather than a powder; if you use that tip out a tiny amount into a shallow container - a pop bottle lid or similar - and dip into that; don't dip into the original pot as an disease would contaminate it)

Right, so you have your cutting (maybe with hormone rooting compound attached) in your hand. Remove the pencil and insert the cutting into the hole. The hole needs to be same depth as the cutting - i.e. the cutting must reach the bottom of the hole, in particular we do not want an air gap under the cutting, so push the cutting in until it is firm. Then put a finger on the compost either side of the cutting and push down pretty hard - again, we want compost in contact with the cutting, not air.

Work around the edge of the pot inserting prepared cuttings; if you just have one or two left over you might put them in the middle, but all the books say to put them around the edge. I find they all root fine so not sure the edge-thing makes a big difference.

Right, so now you have a pot full of cuttings Get a plastic bag and put over the top and secure it around the pot with an elastic band (i.e. the bottom of the pot is sticking out of the bag, not inside it).

Stick it on an East or West facing windowsill, or perhaps under the bench in the greenhouse, i.e. no / little direct light. It should not need watering for a while, but when the pot feels light just stand it in a saucer / bowl of water for a couple of minutes - not longer as the plants cannot, yet, drink much water so we don't want to give very much as the amount we do give will probably last at least a week.

If you have some split-canes you could put those in the pot, once the cuttings are in, and put the plastic bag over that so that the bag doesn't rest on the cuttings. You will get a lot of condensation inside the bag, and the canes will keep it off direct contact with the leaves. (I don't bother with this, but it can help)

If it looks like mould is appearing inside the bag then open it to let some fresh air in, and close up again. I haven't had that problem, and Hydrangeas should root quickly enough that it isn't an issue, but slower rooting things are a race between Rot and Root!

The first sign that the cuttings have taken will be fresh growth shooting from the tips at that stage take the elastic bag off, but leave the bag draped over the top. Fresh air will get in, but high humidity will be maintained. Watch out that watering frequency will increase as the pot will now dry out faster.

At this time of year I would leave the cuttings in the pot until the spring. You could pot them on, but they will then have very few roots in quite a large container (9cm pot each, say) and they will make so little growth over winter that there is the risk that the roots rot from being too wet. If the cuttings had been taken at the end of July / start of August, say, then they would probably be ready for potting on already and get a couple of months growing before winter. They will take up less space, over winter, crammed into a single pot too!

If you see roots at the bottom of the pot then you can be sure that the cuttings are ready for potting on but a couple of weeks after you see fresh growth at the tips is probably safe to start thinking about potting on (apart from my comment about keeping them in their pot over winter).

If you keep them in the pot over winter then consider giving a very weak feed - there won't be much goodness in the compost they are in.

 

Ha! Even found some photos


Prepared cuttings in the pot. Should give an idea of how long the sticky-out bit needs to be, and the trimmed leaves. This photo was a couple of weeks after the cuttings were started off, soe some of the older leaves going a bit yellow.


My row of cuttings by a West facing window, sweating nicely in their poly bags

 

M said she wanted an idiots guide, so reckoning I was the idiot she was referring to I wrote the guide

I learnt by watching people doing it, and I got to ask questions about "why did you do that", so I thought I would try to explain the "whys" ... but different folks have different strokes, all effective, so there are other ways. Mine's the best though, of course

What sort of question is that? If you spotted something speak up rather than have me racking my brains!!!

Well ... the snippets will have two chances, eh?!!

 

You calling me the perfect idiot?

 

My hydrangeas make babies. In fact just transplanted two last weekend. Just look under an older established one, and there it is one coming up 5 or so inches from the mother, and a good healthy 3 foot tall. Just a sharp shovel , cutting downward to get all the root I can and to sever the connection from the mother and up comes a nice one with lots of good roots. Have a nice location in mind and he has a new home. Let see now, think I have 8 babies born that way over the last 5 years . All doing healthy.
But , I have made Calicarpa new babies, by the growth hormone powder thing. Just a pot of good soil, use finger for nice hole, cut healthy stem on a angle, stick stem in powder, put stem in finger soil hole , pack down, Water . Put out side in a sunny safe spot , keep watering for a few days. Then just wait.

 

"Making jam" is a unit of time measure for how-long-to-leave-someone-dangling

Have they layered? or come up as suckers perhaps? (Don't think I've seen one do suckers)

 

By the by, timing-wise, I have some Hydrangea rooted cuttings, taken end of June, which were potted on early August into 9cm pots. I reckon on that timing that they will be ready for 1L pots in late September and that will be enough time for the to get settled in before the Winter; they will stay in greenhouse over winter, kept fairly dry, and the 1L pot will give them room to grow next Spring whilst I am busy with the Spring-rush for seeds, and they will get into 2L pots in May, and be ready for planting out in July (I won't to plant them out in good time before Winter, but they would be happy in 2L until the following Spring).

 

Thank you so, so, much for: the time you took to type that up; the detail you went into; the photos and the kindness behind it all

Now, if my cuttings fail after *that* high level of training ... I'm giving up on gardening!

 

An Update:

All began well and good; the only slight hiccup being, none of the plants I had were favourable to taking 6" piece ... actually, a few of them were barely 3"!

I followed the advice as best I could but didn't have a suitable windowsill - but, I had a blow-away and put them in there.

In October, (remember that slightly windy weather we had? Some called it a storm?), my blow away, blew away along with all my plants and cuttings.

Mr "M" did a passable clean up operation and *only* rescued the cuttings and dumped them, unceremoniously and unbeknown to me, in my shed!

Life took over and they lay, abandoned and forlorn until I remembered them (please don't force me to admit to *when* I remembered them - *hangs head in shame* ). However, once rediscovered, I put them in an outhouse (north facing) and into the "thing" I used to house newly hatched ducklings in (a thrown together gerbil cage base, with an aquarium lid which houses a light).

Now, you would think the poor things were completely doomed since October - and who could blame anyone for thinking so?

But, I am absolutely delighted and over the moon to report:-

2 x pots of (I think a traditional variety) - 8 cuttings taken - FIVE are growing
2x pots of "Bailmer" - 8 cuttings taken - FIVE Are growing!!!!!

2x pots of "Selma" - 8 cuttings taken ... (this is the one that you have to have permission to reproduce?) and I have .. EIGHT growing

Many, many thanks @Kristen for such an excellent "Idiot's Guide". I'm really thrilled at these results, despite the poor things setbacks.