Seeds and cuttings trays alway go moldy

Hi all

I've grown some stuff, with varying degrees of success from seeds and cuttings. No matter how carefully I follow the advice on seed packets and in books, I always get a bit of mold growing on the surface of the compost.

My success rate is never better than about 50/50, although most seeds germinate but then quickly die.

Any ideas where I'm going wrong?

 

Hi clueless.

It sounds like too much moisture is your problem. Remember seedlings are so small that the amount of water that they use is minuscule. The main loss of water will be from evaporation from the surface of the compost, and you can virtually eliminate this by using a transparent propagator top on the seed tray. Consequently after the initial moistening of the compost before the seeds are sown, I don't water for a month or more. What I do is have a dilute solution of copper compound in a spray bottle, and just give them a fine mist every few days to stop the surface drying out. The copper compound, also goes under the name of Cheshunt compound, is an antifungal and should help to kill any mould that you have.

You can't get rid of mould, the spores are all around us in the air. Just don't give them soggy compost to grow on.

The same goes for cuttings. Remember that for the first 10 days or more the cutting has no roots so it can't absorb any moisture from the compost. So you need to water the mother plant well the day before you take the cuttings, so that it is full of water. If you put your pot of cuttings in a polythene bag, it will need very little water.

 

I use shallow round pots for seed (about 4" or 5" diameter) with soil-based seed compost [not Levington peat/peat-substitute compost, which encourages surface algae more IME] cover the seed with vermiculite (not compost), water them with an up-turned rose [see below], and put them in a resealable plastic bag in the kitchen out of direct sunlight (thus I can check them each day, and the temperature is good and constant - choose somewhere else if you have a small kitchen that gets hot when the chef is going full tilt!). Those that don't germinate I re-water after a month or so. Sometimes I stick the bag in the fridge for a few weeks if it still hasn't germinated (for hardy things, not tender plants!)

I find the vermiculite cuts down on the muck that tries to grow on the surface.

I have an aeroponic propagator contraption for cuttings, but this is only useful for certain things - very popular with cannabis growers apparently! but it gives me very close to 100% on Fushias - although they would probably root if I just stuck them in a glass of water.

For anything else I usually use gel2roots [see this blog I can't find a stockist online :( ] - a plastic pot with a sealed tinfoil lid containing gel with rooting compound incorporated. Prepare cutting, stick through the tinfoil, put in tray with 1" of water (to keep leaves humid), cover with propagator lid.

I spray the cuttings and any seedlings that have sprouted, and after either are transplanted, rather than watering - I have a multi-nozzle thingie for the hose that can do a fine spray, and also a hand-held bottle that produces a great spray

Upturned rose method:



I use [url="http://www.haws.co.uk/metal_cans_for_outdoors/4-5litre_long_reach_can.html]Haws watering cans[/url] and they are excellent, but expensive [plastic models also available, a bit cheaper]. The water does not knock seeds over, its just like fine rain. Make sure you start the "shower" going off to one side of the plants, and then swing the "shower" over the plants. The first bit that comes out is a bit more violent!

 

Kristen - how does your aeroponic propagator work - it looks fascinating. It sounds as though the roots are constantly misted from below - but with what? Can you use water, or is is it a special solution. And if you can use it for cuttings, can you not also use the same principle for growing on larger plants? And is this better than or the same as hydroponics? I have never seen any simple hydroponics equiptment on sale, that wasn't tied up with expensive solutions and other equiptment aimed at Cannabis growers. I have seen a completely enclosed system with lights, heat and special solutions for £2000 for growing plants - it was the size of a washing machine. I really liked the idea - but it is a bit over the top for my plants that achieve an 80% or 90% success rate in a simple heated propagator.

One method I have used recently is to put cuttings in small pots of compost in a heated propagator in a light box, and then to flood the floor of the propagator with water. Because the cuttings are in 100% humidity, they cannot lose any moisture so I may leave on as many as 20 leaves. I did this over the winter with some Salvia cuttings and they did wonderfully. 100% success, and growing so fast that within a month of taking the first cuttings, I was taking a second set of cuttings from the earlier cuttings. However I wouldn't like to recommend it, as so much humidity is an open invitation to botrytis - though I never saw it. It wouldn't suit all plants - Pelargoniums would hate it - you can't enclose them.

Your gel2roots method also sounds interesting, but expensive. I would like to know what the chemical is. I have tried germinating seeds on water absorbant gel, that you can buy freely - The gel is also expensive but you don't need much and could possibly reuse it. I also tried seeds on a gel of wallpaper past, which is very cheap, but I think they put some strong antifungal chemicals in which killed the seeds.

 

"how does your aeroponic propagator work"

There are 4 fairly un-subtle jets on an H shaped pipe underneath (the sort of things you get in irrigation kits). These spray onto the underside of the "top plate", and thus the stems, and developing roots, of the plants are kept moist, but also have air - i.e. are not sitting in water. The cuttings are poked through neoprene collars (with a cut one side to the middle) which themselves sit in little cone shaped baskets (probably not necessary, but it adds some rigidity and stops the neoprene collars falling straight through!). You could pretty easily make one from a Tupperware box and a propagator lid, and a few irrigation bits. There is an option to have a heater in the solution reservoir (I haven't bothered.)

I thought it was a bit of a waste having it running all the time and looked for a one-minute-on, one-minute-off timer switch. I didn't find one, so I have a 24 hour timer with 15 minute segments, each set alternately, so its 15-mins-on then 15-mins-off. They don't actually dry out within 15 mins, so that seems to work fine.

First time I used it was with Fushias and I just used water, and they all rooted. Now I add some hydroponics feed ("Vita Link Bio-plus" at 1ml per 10 litres [that's about the size of the reservoir], so my 500ml bottle is going to last me a lifetime!)

" can you not also use the same principle for growing on larger plants"

Have a look on Google and you'll find loads of Forums etc. discussing Cannabis production via this technique. They are getting startlingly good growing results, and of course have lots of control, and lots of it is using home-grown kit - some basic sprinklers and irrigation pipe etc. although I seem to remember some folk moving to misters instead (I think to get 100% humidity, rather than spray, as that probably spread about more and thus kept all the roots happy). However, the system is at the risk of pump / electricty failure, or of part of the root system being obscured [as the roots grow]. Once there are lots of roots it becomes an issue - not so for rooting cuttings of course

I'm pretty sure when I was researching it I saw some outfit that was growing mega quantities of Peppers.

If you want to grow a crop using Hydroponics then I reckon NFT (Nutrient Film Technique) is a good approach. A trough is made with some plastic about 2' wide with the edged lifted up and stapled in the middle, the plants are put inside this [started off in rockwool] and a conventional irrigation tube dripper (well, stream actually) irrigated from the up-hill end and it just runs past the plants. The root mat that develops draws up the liquid by capillary action. You need a tank and a circulation pump at the downhill end. That needs automatic top-up of water, and nutrients added - that used to be done just by monitoring the conductivity of the solution [ideally with an injector to automatically top up the nutrients]. (When I was involved with it [back in the '70s] we had the benefit of a complete chemistry lab on-site which did analytic, so we adjusted the N-P-K accordingly, rather than just based on conductivity, but most folk didn't have that option. It was noticeable that when the Toms started fruiting the stripped the Phosphate in an instant - like they were hungry and feeding selectively!).

"so much humidity is an open invitation to botrytis"

I spray all my cuttings with fungicide when they go into the propagator, but IKWYM.

"Your gel2roots method also sounds interesting, but expensive"

I use it for things that I have knicked from friends. I usually only have a few pieces, so I'm keen to get a good strike rate. Only problem is that the gel dries out, so anything that will take forever to root would then suffer, and that means it isn't any good for a second go - I tried with cling film etc., but they had pretty much dried out by the time the second batch was getting going. "Each pot contains 125ml of parented rooting gel" and "contains 4-indol-3-ylbutyric acid" which is your bog-standard rooting compound AFAIK

The lot I have here was £2.69 for 6 pots, and I get 4 cuttings to a pot [instructions say 3 only] - so 10p a cutting or thereabouts. They are branded Mr Fotergills, and I think I got them in Homebase, but the price sticker is reduced as a "Discontinued line" which is a bit sad, and the domain name www.gel2root.co.uk jus goes to some cyber-squatter advertising site.. Maybe I'm going to have to learn how to do it properly from now on! (Hmmm .... a Mist Propagator from Santa this year perhaps?!)

 

Kristen. Many thanks for your time in posting a very full reply. I am going to have to reread and think a bit more about it. And do some more research.

I take your point about the cost not really being an issue for special items, where you are keen to get a good strike rate. I mentally split my seeds and plants into two groups, one where you want a quantity of something, usually of a plant that isn't that difficult to get hold of, to make a good display in the garden, and the other is where you have something unusual, where you are very keen to get a result, but maybe only want one specimen plant.

Couldn't you have added water to the gel, as it dried out. I would have thought that any water added to the top of the gel would very soon get dispersed evenly through the gel. It worked that way when I used the water absorbant crystals in some experiments.

I did a quick Google on 4-indole-3-ylbutyric acid, which apparently is the rooting hormone used. Do you know what the gel itself was - and does it matter. What I am really saying is couldn't we make our own? Hydrated water absorbant crystals with added rooting hormone? Add more water and an anti-fungal to reuse?

 

" Couldn't you have added water to the gel, as it dried out."

Didn't think of that. I've got some on the go at the moment, I'll try when they are done.

" Do you know what the gel itself was - and does it matter."

Well, it looks like ordinary Agar(SP?) that we used to put in Petri dishes at school to grow swabs of bacteria on.

I'm fairly sure that this was an offshoot from Sheffield University spun out with some venture capital investment - as SupaPlants or somesuch. No idea if they have any other products, but I'm reckoning they have bitten the dust. "Too expensive" maybe, although I have found it worthwhile for, as you say, important cuttings

"with added rooting hormone?"

Would that be important? Or could you just dip the cuttings first?

Clonex make a liquid rooting compound (which I read good things about) and maybe we could just add that to the gel ??

I used to work in a tissue culture laboratory, and we made Agar with some hormones and stuff in it (probably some sucrose to provide energy, I forget now, it was in the early '70s!). Lots of tissue culture still going on, I reckon whatever they use is going to do the right sort of job. Although we did everything in clean cabinets to avoid getting any bacteria in the cultures 'coz they would grow very quickly too! so maybe that is the bit that the SupaPlants folk solved?

But I like the way you are thinking!

 

Too much moisture, I bet that's it, thanks for the advice PeterS.

I read in a book that for cuttings, some people use sphagnum moss as the growing medium. Has anyone tried that, and had much luck?

I like the idea of the aeroponics/hydroponics and gel ideas that have been bounced about, I might look into that.

 

"I read in a book that for cuttings, some people use sphagnum moss as the growing medium. Has anyone tried that, and had much luck?"

I reckon Perlite would be your best bet. Inert, free draining, unlikely to grow algae etc.