Is it worth using Hormone Rooting Powder?

Right, based on your recommendations I'll give hormone rooting powder, or gel, a miss and try it the natural way. The money I've saved on the powder will go towards some cutting compost.
Also, I've started experimenting with trying to root cuttings by just plonking them in some water. Rooting in water seems to be just as controversial as rooting hormones but it's so easy I figured I would just try it myself. I have 4 ivy cuttings and 1 tree cutting to try. The latter was just a 'pleeease work' type deal though I don't expect it to having never read anybody having success that way.

 

I will be surprised if you have more success with Water than Compost. Lots of things will root happily in water, but in the main I think things need air as well as water. I'll be interested to hear other people's views.

 

I agree with Kristen - its only some things that will root in water. I would love someone to explain the principles behind that so I would know what types will and what won't.

 

I haven't a clue what types will root in water either, but I'm sure ivy is so common and easily spread that it must be one of them! Trees on the other hand almost definitely will not, I assume.

A bit of research would be nice so there was a book with some kind of list that said "these will work, these might, anything else will not."

 

One other thing to consider. Cuttings started in water have to be acclimatised when transferred to soil. I suggest putting a clear plastic bag over Plant + Pot for the first week or so as the roots won't be used to having to get their water out of a Soil + Air mix!

 

Kristen,
After how long should you take the bag off?
My hot lips have been covered about a month. One looks distinctly mouldy.

Success or failure, it's all part of the fun...

Glad someone asked about root powder cos i wondered too.

Cheers
D

 

Mouldy is not good :( Two possibilities: Either the plant hasn't rooted, and "That's It" :( or it has rooted and is miserable at being in a 100% humidity bag.

For my cuttings in pots, which are then stood in clear plastic bags, I tend to open the bags periodically - once a week say. I get them out and see how they are doing which has the effect of giving them a change of air. (Don't disturb the cuttings though - wiggling them in their soil won;t help the roots to form, so be careful that the leaves don't "catch" on the inside of the bag if you are taking the pot out - its probably enough to open the bag, look inside, remove any leaves that have died [cleanliness is important at this stage - think of a sick child, you want to do everything to help it recover, whereas as an adult you probably just brush it off an get on with life!], and then just seal the bag up again.

When I "take the bag off" I do it in stages. I open the top of the bag, but still with the bag stood up around the pot & cuttings - so any water vapour has to go up vertically before it can escape - so it keeps a micro-climate of humidity around the cuttings - but the top is open to fresh air. After a few days the plant can probably manage on its own.

That's my theory anyway! Sometimes the cuttings get forgotten and in spite of my best intentions they are abandoned and neglected but they root anyway (or not!)

 

ExLabMan - I would agree with Kristen about opening the bag. But I would be inclined to do it more often - or cut a little hole in it and blow into it once a day.

I don't have any proof - but my thoughts are that a cutting is still growing in a bag. You can often see the leaves growing and you are trying to grow the roots as well. For a plant to grow it needs carbon dioxide, and there isn't much weight of carbon dioxide in a bag compared with the weight of foliage and roots that you are trying to grow. So I would want to refresh the carbon dioxide at regular intervals, and this might also help keep mould at bay.

My other feeling - and again I don't have any direct proof - is that once a cutting is in a high humidity area, I would want to get some bottom heat into it. The warmer it is, within reason, the quicker the roots will grow. If its too cold it won't grow and that is when mould starts to take over.

Just an observation, which isn't necessarily related to the particular problem. I root quite a lot of Salvia cuttings in a lightbox with bottom heat. Sometimes they can have a huge mass of roots in as little as 8 days. I am a bit naughty and quite often at intervals, after say 5 days or 7 days, I will carefully take the cuttings out of the pot by turning it upside down, let the compost fall away and just see how much root has formed. If a cutting roots after say 10 days, the roots don't grow one tenth each day. Very often there will be no roots at all for the first 8 days, then they grow at a massive rate over the next two or three days. Its as if they spend a long time making up their mind before they actually start. I have done that to dozens of cuttings, and whilst I wouldn't recommend the method, I always pot the cuttings up again afterwards and to my knowledge I have never lost one by doing it.

 

Thanks guys. Great advice as always.
Keeps things interesting on a cold nightshift.

Cheers
D

 

To offer my own people of amateur advice Exlabman: instead of a plastic see-through bag over the top of the pot I'm told it is perfectly acceptable to use a discarded drinks bottle cut in half, presuming it is clean and empty of course.
That way, you can lift it on and off with less chance of catching the plants and when you want to slowly get it used to normal air you just unscrew the cap on top.
Also, if you need a greater size than 1-2 litre bottles you can always buy those 5litre bottles of water.

If the above is incorrect in any way I hope somebody says something, if not I hope it helped.

 

"I don't have any proof - but my thoughts are that a cutting is still growing in a bag. You can often see the leaves growing and you are trying to grow the roots as well. .......... I would want to get some bottom heat into it. The warmer it is, within reason, the quicker the roots will grow. If its too cold it won't grow and that is when mould starts to take over."

Good point Peter. In future I'll stand my cuttings on my windowsill propagator (although in mid Summer I doubt its contributing much to heat! but come Autumn I ought to get it out of storage where it lives from May to January normally ...)

"For a plant to grow it needs carbon dioxide, and there isn't much weight of carbon dioxide in a bag compared with the weight of foliage and roots that you are trying to grow. So I would want to refresh the carbon dioxide at regular intervals"

Not convinced about this. I reckon that the amount of CO2 that a cutting can absorb through its leaves is going to be negligible compared to what is in the bag. However, boosting the percentage in the bag might be an idea; I think what comes out of your lungs is not boosted much either - but I don't know for sure. need a little "QI Google" to find some data ... Either way I can't think of a convenient / cheap source of CO2 - could I open carbonated drinks bottles into the bag for my cuttings? :D.

"I am a bit naughty and quite often at intervals, after say 5 days or 7 days, I will carefully take the cuttings out of the pot by turning it upside down, let the compost fall away and just see how much root has formed."

What about transparent pots? (The sort that are used for Orchids). I wonder if that would help know what is going on ... I wait until I see roots coming out of the draining holes, but that can be rather late in the process on occasion - i.e. roots have formed well but not become visible at the draining holes

 

I would imagine the sunlight would dry out the soil easier if the pot was transparent, I might be wrong.

 

Kristen - you may have misunderstood me about the carbon - or I might have just got it all wrong. :D

A long time ago I head on the television, that a question was put to M.I.T. (USA) students. If you have a tree that weighs 100 tons - where has it all come from? It was stated on the TV that something like 90% of the students got it wrong. They said that it had come from the soil. The answer is that the vast majority of the 100 tons had come from the air, from water and carbon dioxide and of course sunlight. Only a small amount had come out of the ground - viz other minerals. When you burn a tree, you reverse the process and release the sunlight as heat, and the water vapour and carbon dioxide are returned to the air. What is left, ie the ash, is what was drawn up from the soil. Which of course explains why it is such a good idea to return wood ash to the soil. The thought is bizarre but logical. Obviously the water is drawn up from the soil, but it arrived as rain. If you took 100 tons of any material just from the soil, you would leave a large hollow - but trees don't.

In the case of a cutting, 40% of the weight of the new leaves and roots that grow are made up of carbon (just Googled the figure). All that carbon must come from the carbon dioxide in the air in the bag, not from the soil. In air carbon dioxide only makes up about 0.04%, so my feeling is that it would be quite easy to use it all up unless it was replenished on a regular basis, by removing the bag and changing the air orjust by breathing into the bag instead - without removing it.

I do sometimes take cuttings in transparent containers (picnic cups) and they do well. However you don't actually see the roots till they have reached the side of the container - ie they are the finished article. If you want to inspect work in progress I found I still had to remove the cuttings.

HBK - Sunlight didn't seem to be a problem as I had a large number of pots in a propagator. But I did some research on the effect of sunlight on roots. Opinion was divided but the general consensus was that it didn't have any detremental effect

 

Does rooting powder contain Mycorrhizae (or whichever ones appropriate)? If it is, I'd say its probably useful, because of the help that the symbionts give later in life

http://en.wikipedia.org/wiki/Mycorrhiza

I just learned that in Uni

 

"Does rooting powder contain Mycorrhizae"

Mycorrhizae is a different chappie. Its a symbiotic fungus I think - so an organism that grows hand-in-glove with the developing roots.

Hormone Root Powder is a hormone (most probably Indolebutyric acid or Naphthylacetic acid) which stimulates the plant to create roots.

I think you would need to have roots there in the first place for Mycorrhizae to be able to do its magic - although I think I have seen cutting compost preparations that include it.

"you may have misunderstood me about the carbon"

No, I don't think I did, I just guestimated the numbers in my head and thought it improbably that a cutting could "consume" the CO2 in a bag quickly - if it does you should suck all the pure oxygen out of the bag before you blow CO2 back into it - I can see gardeners up and down the land falling for this new craze!

But I have absolutely no confidence in my mental maths guestimate. But I am curious to know - how much weight would a cutting put on? and how much CO2 will it use? presumably if the CO2 level in the bag is lowered, by the plant, it will become harder for the plant to extrract more CO2 - so "how much does it use" needs to consider the point at which CO2 level has fallen enough to cause the plant a problem. By daughter is doing A-lvel chemistry ... I'll ask her :thumb:

I've always wanted to leave the humidity high in the bags, so kept them closed (in the main ...) however your idea of blowing into them would provide a more CO2 and also a nice humid atmosphere too. I might be persuaded to change my ageing ways! Would you advise talking to them too? What would I say? (Actually, normally I only talk to the ones that are not growing well and it is usually something along the lines of "You'll be on the compost heap next week if you don't buck up"