Garden Organic 2020 Members' Experiments

[triffid]

Interesting research lineup this year https://www.gardenorganic.org.uk/2020experiments

1. Getting a head start with winter green manures
2. Alternatives to plastic mulches
3. Can mesh netting reduce potato blight?
4. A national view of pests and diseases in gardens and allotments

I've signed up for all bar the potato blight trial as it is fully subscribed. However, I will experiment with mesh on my own potatoes and tomatoes.

https://www.bhu.org.nz/future-farmin...d-pest-control

[Galina]

The problem with mesh is twofold. It needs to be well clear and not touching the growing plants, because mesh can hold moisture. It also needs to be very fine mesh because the blight spores that cause the problem are very fine. I think you will still get the spores, but the mesh does perhaps stop some of the moisture which activates the spores. A solid roof rain cover that does not touch the plants and also does not restrict air flow (so the plants dry fast after getting wet) in theory would be better than a mesh. This is why they get blight outdoors but stay safe in the greenhouse. But what do I know ..................

As you say very interesting. The green manure experiment is all about "undersowing" rather than green manuring an empty bed.
I think they are hoping that these alternatives to plastic mulches will work like plastic all season and then biodegrade over winter without shreds and bits coming loose and being blown around over winter. The pests and diseases survey is also interesting, because they may have studied organic farmers but presumably never organic allotment holders and gardeners. For both these groups there must be a much greater crop diversity than even on organic farms and that might mean more or fewer pests than with a relative mono culture. An interesting investigation and they plan to follow it up for several years to show trends.

Will follow with great interest. And if I do stand corrected regarding the mesh, it will be all good

[triffid]

The mesh used in the experiments is probably not as fine as you'd imagine. With 0.6mm holes it is small enough to stop wee beasties like tomato potato psyllid, but definitely too large to hinder spores. Therefore the mechanism isn't via 'filtration' of spores - it is still unclear how it is having an effect on disease but its influence on UV is speculated to have a role.

That being said, the mesh is another source of HDPE contamination for soils, which contradicts the reasoning behind the search for plastic-mulch alternatives somewhat.

Looking back I think I inadvertently set-up my own version of the winter green manure trial this past summer. Between the rows of potatoes this spring I sowed crimson clover. Once these were harvested I sowed runner beans and bush beans. The crimson clover spread and filled the gaps between the beans. I cut it back once as it was too tall for the little bush bean plants. It was left in the ground after harvest and is still providing good cover, though I believe this particular green manure is winter-killed. Obviously not frosty down here yet!

[Jang]

Interesting research lineup this year https://www.gardenorganic.org.uk/2020experiments

1. Getting a head start with winter green manures
2. Alternatives to plastic mulches
3. Can mesh netting reduce potato blight?
4. A national view of pests and diseases in gardens and allotments

I've signed up for all bar the potato blight trial as it is fully subscribed. However, I will experiment with mesh on my own potatoes and tomatoes.

https://www.bhu.org.nz/future-farmin...d-pest-control

I’ve just signed up for Nos 1 and 2 as well. Will be very interested to see how both experiments go.

[jayb]

Interesting experiments, I look forward to your progress. I haven't been a member for a number of years. Perhaps I should think of joining up?

[triffid]

I didn't know you could be a member of the HSL without subscribing to Garden Organic first!

[jayb]

You used to be able to, they changed the ruling a few years back for those joining up. And when my subscription was due for renewal I nearly canceled it, but luckily they were really helpful and explained the changes over the phone. I chose to stick with HSL only as funds were short at that time. I'm glad I did now.

[triffid]

Anyone made a move to start yet? Plan to get the mulch one and onion sets in this weekend. And the beans for the green manure experiment need planting soon, might do that this afternoon.

[Jang]

Yes, I've done both of those.
I followed instructions on the beans against my better judgement. The instructions specified early April for starting the Cobra beans. They're already planting out height which seems much too early and risky. I guess they'll hang on in their deepish roottrainers for at least another week but it might be pushing it after that. I think your timing for that experiment is much more sensible.
The onion mulches are a bit fiddly but fine. So far I have shoots on the onion sets about evenly for each mulch, including no mulch.

[triffid]

Nice! Were those pegs included? I haven't inspected what they sent aside from the onion sets.
The instructions for starting the beans are really early. I wouldn't normally sow until May, even this far south.

[Jang]

No pegs provided I’m afraid.

Yes agreed re timing. I’ve sown a few dwarf beans in modules already, with the thought that I can fleece them if necessary. But risky, and climbing beans for me are more difficult to protect.

[Jang]

Today planted out the beans for the other Garden Organic experiment - Cobra beans underplanted with yellow trefoil as green manure, on the metre square to the left. The square on the right is to be sown with yellow trefoil in the autumn.

I think you were planning to do the same a few days ago, triffid. All OK?

[triffid]

Looking very happy and healthy. You have beautiful soil!
My Cobras have been soaked but are yet to show signs of life. I did buy some more yellow trefoil to undersow the the other beans and corn this year.

[Jang]

Yes, I’m lucky with my soil. It’s workable most of the year and the generous amount of rain we’ve had in the last few days has been very timely.

My Cobras germinated 24 out of 25 in roottrainers where they sat for three weeks, so hopefully your seed is as good. Think perhaps I could have made the wigwams wider to occupy the allotted space more fully.

Your yellow trefoil experiment extension will be a really good test. Apart from anything else I’m interested to see whether the trefoil growth outstrips weed growth.

[Hector1]

Not strictly on topic: Do you folk think that the Trefoil / Red clover would work with other crops , wondering about trying with Broad beans.?

[triffid]

One can only experiment and find out. https://www.agricology.co.uk/ has many informative articles and downloadable resources on the subject.
Also Cotswold Seeds https://www.cotswoldseeds.com/knowledgehub.asp

[Hector1]

Thank you. Very useful links.

[Jang]

Alas, my Cobras for the HSL experiment succumbed to Monday night's somewhat unexpected frost. A sorry sight now.

I'm growing the orphan Haricot à Rames for HSL and had started some in root trainers so decided to replace the Cobras with those. It won't be entirely satisfactory for the experiment as I need to infill with direct sown seeds so the timings etc will be less conclusive, but it's the best I can do in the circumstances.

[Galina]

Sorry to everybody who lost plants. An unusually late and severe frost. I don't think the variety of beans is all that critical though, just the underplanting.

[Jang]

Yes, that was my thinking too. It was a little difficult to plant replacements without disturbing the underplanting but hopefully good enough.

[triffid]

It wasn't the frost - something was not right with the potting mix. Everything else is unscathed, fortunately.

[Hector1]

I have some Cobra spare, if it helps.

[Jang]

Thanks Hector1 for your kind offer.
I am growing so many beans that I took it as an opportunity to use the wigwams erected for the Cobra for another variety which I need to grow quite a lot of. As Galina suggests, the experiment is really checking out the effect of the underplanting of green manure. So as long as the two wigwams have the same bean, the experiment should be valid.
I hope HSL are of the same opinion!

[triffid]

Thanks very much for the offer Hector but, like Jang, I'll be using the allocated space to plant a different variety. I feel a little bad for the Cobra, though. So quickly pushed aside, replaced - no second chance!

[Galina]

The results for last year's member's experiments are in. Here is the archive of all experiments. https://www.gardenorganic.org.uk/mem...,TS0FR,RO645,1