Good improvements to the greenhouse, I think they are really required if you're going to use one of these. The main issues for me were airflow and keeping the thing from blowing away. You also have to be aware of temperature fluctuations, it can actually get colder inside a greenhouse at night than outside and this can happen even in a more expensive glass greenhouse or polytunnel.
@RFranks6 күн бұрын
Good experiment! I put bark chippings at the base of my tomato plants this year and also noticed the ground seemed stayed moist longer than with just compost. I wonder how the different mulches affect the temperature of the soil too, I've heard bark chippings can make the ground slower to warm up earlier in the season which may be an issue for some plants.
@AlexanderOrion6 күн бұрын
How does this behave in winter? I live in central europe where temp gets around -20 degrees celsisus? Is it possible to mantain at least 6 degress celsisus inside? Thank you
@alexgrowsfood6 күн бұрын
Hi there! I really don't think that's going to be likely. Here, with a lot of taping the cover to the poles and even with a lot of thermal mass inside (bricks, water, compost, etc), I probably wouldn't leave much out below -2C (assuming a ground frost at +2C or lower air temperature), especially in the winter where the heat storing hours are low and the heat loss hours are high. My DIY improvements in my more recent video get me about 3C improvement overnight and the basic unimproved greenhouse probably gets about 1C over the forecast air temperature (I've not directly measured the outside temperature). It might be possible to add a wall of bricks to the inside of the cover and position the greenhouse sideways facing south (long side facing the sun) so the heat build up and less airflow gets you more protection but I've not tried it and I'd still be hesitant to trust it. The Romans used to do something similar to grow lemons in the UK in the open air. But I think the coldest we've ever had here was -10C in Jan 2023 and without any added protection (and a few holes in the fabric) it was about the same in the plastic greenhouse. But I imagine even a poly-carbonate or glass greenhouse might struggle at -20C without a passive heat strategy or even active heating - maybe a water heater connected to an outside mains electric source and dunked in a water butt? Not sure how safe that is or how expensive but some kind of heat source might be a good idea in those greenhouses where the airflow is less of an issue.
@AlexanderOrion5 күн бұрын
@@alexgrowsfood Wow, thank you for your elaborate answer. My question was stupid from the start, I then researched green houses and understood the phenomenon and different types. And yeah in Romania at least where I live we have -20 and even more for prolongued periods. Thank you for the info. Cheers!
@wormfriend562517 күн бұрын
That was such a interesting and informative video. I will be using the grass on my allotment where we have no access to water and I really struggle to get water there. Thanks Alex brilliant experiment.
@alexgrowsfood6 күн бұрын
Great stuff. Honestly, it holds water for ages. It doesn't rain much in Cambridge (lowest rainfall in the UK) but grass is like magic. Was surprised at how flat that graph was but it clearly works even in shallow soils
@laszloposzmik582923 күн бұрын
Thank you for the informative video! It is like a scientific experiment. Let's try in the next year in my garden,
@alexgrowsfood6 күн бұрын
Thank you! Good luck!
@jacquelineclauson489124 күн бұрын
Great experiment, good to know.
@P.I.E.27 күн бұрын
The problem I have with using any kind of mulch is that I like for my seeds to sprout naturally. I prefer no mulch in my containers. It allows me to re seed and also to notice any issues with the soil.
@alexgrowsfood6 күн бұрын
Yeah, this can be a bother. In principle the grass can break down so by next season the seeds should find their way to the bottom but it's probably going to be less reliable than directly coming into contact. Might be worth an initial mulch early in the season and not topping-up and leaving it to decay/thin out by the autumn. I've not tried it but could be worth experimenting on a small area
@P.I.E.6 күн бұрын
@@alexgrowsfood all I have is containers (for now). Plus, I tend to over-seed. It works for me. I would also be interested in a larger scale experiment.
@thehuntfortruthАй бұрын
This is actually a really good video
@alexgrowsfood6 күн бұрын
Ah thank you so much! Glad you enjoyed it
@GARDENER42Ай бұрын
I use grass clippings to mulch my 30litre potato containers. best free water retention material there is. Was surprised at how ineffective home made compost was.
@alexgrowsfood6 күн бұрын
Amazing. Yeah it's remarkable. I guess compost is so soil-like that it basically behaves the same and the water transfer at the interface is basically unobstructed - unlike grass/hemp. I did suggest that the compost lost more because it might have had more water initially but it also had less clay content so the water can move much faster, including to the surface. If hemp was free/legal to grow (without an expensive licence) I'd do it but, failing that, looks like grass is terrific and it grows itself.
@frankw9836Ай бұрын
i was thinking about buying one of this BUT after watching this, i would say NO . I am in Northern Ireland and it would last one day
@alexgrowsfood6 күн бұрын
Yeah, they need reinforcing that's for sure. I did do a follow up video about storm-proofing them but eventually you'll get perforations that cause bigger issues
@frankw98366 күн бұрын
@@alexgrowsfood I did all the reinforcement I could but nothing can withstand the horrible weather in northern Ireland
@xperimental1974Ай бұрын
is that because hemp mulch has less big pores compared to barks/chips? so water is not easily loose through small pores?
@alexgrowsfood6 күн бұрын
I think so. My guess is either water can't transfer vertically as fast because it has to transfer between linear grains (mostly within the material) or the air can't get to it so humidity around the grains are high and evaporation stays low. I think that's why grass did a little worse than hemp but much better than bark. The main counter arguments are colour: hemp is white so potentially a lower temperature at the surface and evaporation slows and also the bark had decayed slightly so had some soil-like / compost-like material in it and because those particles are so small you get a different dynamics (I think the water moves externally to the material - like a suspension or via surface tension on a microscale and can move pretty well in all directions). It's been a while and I've not looked into the microscale mechanics in that much depth but that would be my guess.
@Wings91Ай бұрын
They were good tips. Thank you.
@enlancementАй бұрын
careful the grass clippings don't reduce nitrogen content in the soil... dry them out first
@EntropicembraceАй бұрын
Interesting findings! I always felt it odd that it seemed when after applying bare compost to pots it would drain out faster, glad to see there’s further evidence to that!
@alexgrowsfood6 күн бұрын
Yeah it's weird but I guess it's basically soil and has very little clay content so the water can move quite fast through it too. Possible you'd get an improvement in sandy soil in pots if the compost was very stodgy but not in my clay-heavy patch.
@RFranksАй бұрын
Very useful experiments! I'll definitely give perlite a try. I had some success surrounding plants with comfrey leaves, the slugs and snails seemed to prefer eating them over the plants.
@alexgrowsfood6 күн бұрын
That sounds smart. I saw someone use rotting fruit - pears maybe - nearby as a decoy, but I've not tested it. They don't seem to be interested in apples
@helentcАй бұрын
Great video! Can you clarify what the hemp is? Is it seed or the hull? Thank yoU!
@alexgrowsfoodАй бұрын
I'm not absolutely certain but, to me, it looks like they've chopped up or shredded the dried stems. They are very flat, very small rectangular pieces. I've been using AubiChick which is meant to be organically grown and used for chicks and chickens rather than the larger pieces they make for horses. They state they use the 'core of the plant'
@taniapachecomicrogreensАй бұрын
Hello, dear grower, I also grow microgreens, but with substrate, (Carolina Soil, earthworm humus, vermiculite and perlite, etc., together with coconut fiber, I mix everything, I don't use coconut fiber alone, because in my country (Brazil), people who use them, use them in hydroponics, and add nutrients to the water. Do you add macro and micro nutrients to the water because it is an inert substrate, I don't know how it works, I would be grateful if you could help me? .
@alexgrowsfoodАй бұрын
Interesting question. I've never tried hydroponics, but I'd be surprised if you'd _need_ to add nutrients. For these ones I harvested them while they were really really young so you can rely on the energy stored in the seed. I grew them in the surface of pure coir. I think if the plant takes more than a week or two to go from germination to finished or you want more nature leaves, I'd consider a nitrogen source. But for these and for things like bean-sprouts, a sterile environment and moisture is all that's required. I'd expect similar behaviour in water (but happy to be corrected if someone else sees this or if you want to try it and report back)
@manasikashyapАй бұрын
I’ll have to try these out for my fruit trees! Thank you!
@alexgrowsfoodАй бұрын
No worries, just be sure to give them a lot more water - either a long drawn-out watering over hours (potentially) or maybe doubling up the soaker hose. It depends on the watering requirements of the tree and your soil type & structure. If it helps, I get through about 5L of water a minute over a 75m length
@lynneclark5879Ай бұрын
I use a mixture of grass clippings and leaves which I shred with my weed whacker in a large bucket, works great
@Cody_RamerАй бұрын
Would love to use soakers but they are stupidly expensive, so will have to wait a while..
@alexgrowsfoodАй бұрын
Yeah they are quite the investment. I slowly bought mine over time (and one was given to me - by luck, not by the company) or anything) but I think they'll last long enough to be worth it and I suspect more cost effective than a drip system if you have dense plantings. Not cheaper than manual or a sprinkler though (sadly).
@spakchitownАй бұрын
Very entertaining! 😂
@lilianashore2086Ай бұрын
that took me by surprise! I wasn't expecting grass clippings to do such good job
@alexgrowsfoodАй бұрын
It's an amazing result. I unpacked the experiment not long ago and, while it has rained a bit since, there was so much moisture still in there. Still felt like wet clay on the top and stuck to my hand. Hemp was great too but it isn't free.
@Kristers_KАй бұрын
I generally use geotextiles for weed control, but depending on the type, they don't always prevent water loss, particularly in the cut open planting spots, so this year i use that and a layer of straw on top. I can say for certain that straw/grass seem very effective at retaining moisture in the soil beneath it, as well as maintaining good soil temperature...interestingly enough.
@alexgrowsfoodАй бұрын
That's really cool. I guess you still get decomposition and nutrients permeating through the fabric and into the soil too.
Ай бұрын
Cool, thanks!
@WatchoutforsnakezАй бұрын
What a nice video. I thought I was soooo great for using compost to mulch. 😂
@alexgrowsfoodАй бұрын
Same. 2022 was all no-dig beds at half thickness and called it done, but turns out it's very soil-like. Deeper compost will help (water takes a long time to move, especially in clay) but yeah... Compost with grass clippings on top is the way imo
@Rebekah-BodyIlluminationАй бұрын
❤❤❤love this. Excellent work.
@alexgrowsfoodАй бұрын
Thanks Rebekah!
@marksminisАй бұрын
Finally! Some science to measure which is best! Thanks again Alex great info! ❤ Now I just need to find that hemp…
@alexgrowsfoodАй бұрын
Thanks Mark! Imo grass is probably better anyway tbh. It's free and doesn't blow away as much or breakdown as fast. No pesticides either
@marksminisАй бұрын
@@alexgrowsfood ha, but no grass clippings around here. Grass lawns take up too much water and we live in a desert so everyone has artificial turf 🥵
@craterinaholeАй бұрын
Wow, you made your point quickly and efficiently… thanks for respecting my time, more people on KZfaq should take a page out of your book. I’m subscribing now
@alexgrowsfoodАй бұрын
Thank you so much! It's hard to make videos this condensed so appreciate the comment
@artur_pinskiАй бұрын
Great scientific approach. I wonder how hay/straw would perform... Probably, in terms of volume, cost, and water retention, a mix of hay, grass clippings, and bark would perform best. What do you think?
@alexgrowsfoodАй бұрын
Thank you! I imagine hay would be a lot like grass, I imagine straw wouldn't be too similar but my guess is they pack less efficiently by volume and allow more air flow to/from the soil (and any soaking up of moisture to be faster and more coherent) so I'd guess a little lower. I doubt there is much in it though and it'll depend on exactly how it's cut up. My guess is a mix would promote more evaporation than pure grass/straw (more gaps, darker overall surface colour) but layering might do a better job. In reality you'd probably have something like compost over a bed, with grass/hay on top and using straw in pots and a thicker layer of bark/woodchip on the paths and around trees. Think this is a standard picture and it sort of makes sense really.
@artur_pinskiАй бұрын
Thank you for replying! I am more interested in mulching around the trees, so mix or layering seems like a better option. Would you mind telling which program you have used for plotting your data? I know a few but do not recognize this one :)
@alexgrowsfoodАй бұрын
@@artur_pinski No worries. I use matplotlib in Python for all my plotting. I have lots of snippets of code lying around from my PhD days. I swapped the font and use other default/custom parameters so it's not the easiest to spot. The line animation was a crop effect in the video editor though.
@victorvictor2754Ай бұрын
Using transparent bowls destroys this experiment.
@alexgrowsfoodАй бұрын
Not really - the relative rates of evaporation are unaffected. There are lots of limitations (moisture levels in the mulch, destruction of soil structure, being in bowls at all) but the bowls being glass isn't at the top of the list
@SoberOKMomentsАй бұрын
Very good information. Thank you.
@alexgrowsfoodАй бұрын
Thank you, very welcome!
@barbaraarsenault1192Ай бұрын
Useful video.
@alexgrowsfoodАй бұрын
Thank you! Glad it was helpful
@pipertrippАй бұрын
matplotlib... nice.
@alexgrowsfoodАй бұрын
The comment I was waiting for. Had a ton of code lying around from a phd. The best imo
@pipertrippАй бұрын
Im a big fan of R but python is a fine language and more general purpose than R.
@pipertrippАй бұрын
Really enjoyed your research project here. Interesting stuff.
@alexgrowsfoodАй бұрын
Yeah, the syntax is just really nice to work with. I went Fortran->Python->C++ but Python feels natural. I did an R course and you can definitely feel how it was designed for a given task, never really managed to displace Python for me but super high uptake in biology and researchers without programming backgrounds
@Dev-lc4cdАй бұрын
Could the reason that the wood chips performed worse than the hemp and grass clippings is because of the larger size of the wood chips?
@alexgrowsfoodАй бұрын
I think so. I spent a lot of time studying how things pack together and my expectation would be that the large and long pokey shapes pack together inefficiently with a lot of holes in between and that allows more air to flow so evaporation should be much easier. It was very windy too and I expected a high airflow effect. Additionally the bark came with lots of dust/dirt which is probably partially broken down bark, but I imagine that soaked up water and helped it wick to the surface too. Lots of people have also pointed out the dark colour causing a heating effect. Some mentioned using 6 inches of bark for good mulching and that makes sense for all of the above imo. Just some thoughts. Imagine if you could get more spherical or more regular cubic shaped wood chips, they'd do a lot better.
@Dev-lc4cdАй бұрын
There's so many interesting videos about mulch, but I haven't found another video that does this sort of of comparison testing of mulches. Comparison testing videos are one of the most interesting and informative types of videos, so much so that there are plenty of KZfaq channels that are only about comparison testing different products. I just thought I mention this because clearly it has something to do with the healthy amount of views this video has received. Well done. You're testing not only demonstrated some really good info, but also inadvertently raised so more interesting questions. Like, why exactly was the the hemp and straw so effective at preventing evaporation? They're both fibrous materials, presumably designed by nature to be effective at wicking moisture, and the hemp in particular was finely ground, close in consistency as the typical potting soil. Therefore, one would think that the hemp would have preformed as well as the compost, quickly wicking moisture up from the soil. So there's another factor in this picture, regarding the inherent wicking efficiency of the material used, that I would like to see explored.
@alexgrowsfoodАй бұрын
Thank you again. I definitely have my theories - water moves faster through soil through pores and so does air, so a loose compost probably has little effect while hemp is solely through moisture absorption and transfer between the plant material (probably cellulose, which I expect should bind strongly with water molecules) so be very slow. Other people have rightly commented on the colour and heat absorption. It's probably a mix - the heat helps when the moisture gets high enough to evaporate. Not sure when (or how) it could all be tested for sure but I suspect it's something along those lines.
@sonofsouth2800Ай бұрын
Quite funny
@alexgrowsfoodАй бұрын
Thank you! Es-cargo still cracks me up
@kensawkaАй бұрын
Good job on this. Great idea and thanks for sharing it. In Zambia I also have access to rice hauls, peanut shells, leaves and other things I use for ground cover. I wonder if you can do more comparisons with these things as well as plastic, and other items people use to cover the ground (old roof tiles), etc.
@alexgrowsfoodАй бұрын
Thank you! Honestly these were just the materials I had lying around. I'm not sure where I'd get some of those tbh but I've heard good things about the rice hulls. Plastic sheet might be fine but be careful not to heat the soil too much or limit oxygen transfer and imagine that one would be the most soil type dependent of the bunch.
@carlasaxon2235Ай бұрын
But when it rains the rain is going to do the same thing anyway if its a heavy rain 😂 so even if your trying to prevent those things from happening mother nature always finds away lol. Maybe better to use inside a green house so you can control everything better
@alexgrowsfoodАй бұрын
It's a game of probabilities really. Less coverage is less likely to incur problems. In the west I sort of take your point (I actually think the repeated light rain is a bigger problem) but I live in the driest part of the country and there really isn't much rainfall at all, even this year it wasn't that extreme
@aliceinwonderland7594Ай бұрын
Bravo Alex, great info well timed as here in Melbourne Australia quite cold atm am keeping soil bare after tidy up weeding etc... for planting new round of veggies and herbs and will use grass clippings as we have it a lot here without any toxic additions. Cheers.
@alexgrowsfoodАй бұрын
Thank you! Honestly it's such a win that a homegrown item like this is so good. Forget the compost, straight on the ground for organic goodness at no cost but a weekly mow. Sublime result
Thanks mate. You almost got a graph of the gradients of the time series, would have been sweet but uber nerdy
@user-ey4uy7vl6dАй бұрын
@@alexgrowsfood Well ... It-[All]-'Started' With NEWTON's-Fluxions ... The-'Greatest''-DOODLES of [All]-TIME So-To-Speak!!!??? >(*U^)< (Joke) *Wink*
@KingLutherQАй бұрын
how about 1 inch deep of pee pebble stone (gravel), 1 inch deep of sand, and a plastic liner?
@alexgrowsfoodАй бұрын
Assuming that's bottom-up, I guess the sand would trap the moisture. Top-down, you could probably skip some of those as I imagine the plastic does a neat job. Just be careful with restricting airflow and not overheating the soil and consider alternative ways of feeding the soil, including adding carbon.
@BroqueCowgirlHomesteadАй бұрын
@Yogi Hollow Farm interesting.
@lynnevans7248Ай бұрын
This is great!!!😊
@alexgrowsfoodАй бұрын
Thank you so much!
@saethmanАй бұрын
Interesting. Would be nice to see this experiment again where you add the water on top of the mulch (this experiment was more of a "evaporation prevention" experiment, would be nice to see if the results would differ from a precipitation-soakthrough-evaporationprevetion experiment)
@alexgrowsfoodАй бұрын
Yeah I very much wanted to measure evaporation rates to support some hydrology simulations I was running. It's also an easier setup because watering the bowl and waiting for it to seep into the soil is dependent on the mulch but also the soil type and structure and it could be quite slow and differ a lot between areas. We then probably want to look at moisture build up and then it matters how often and when in the day I water the bowls. Agree it would be cool to know the net effect of adding mulch from a top water scenario but I very much chose the simple option (just measuring evaporation for an irregular bottom watering scenario). Might follow up though on water content if I can get my simulation working and apply it to different soil types.
@MrDjafal1Ай бұрын
@Alexgrowsfood how is sand in comparison, could u please test it ❣
@alexgrowsfoodАй бұрын
I'm not sure about sand. It gets quite hot and is quite small so good at restricting airflow but it also soaks up water. My guess would be it doesn't do as well as the top two and it won't feed the soil. If I do another set I'll write it down but it would have to be a complete set to account for the weather which is the main driver.
@VinInTheGardenАй бұрын
love the video, mate. I recommend another long form experiment using the same materials but analyzing water content IN THE GROUND with a moisture meter. Cheers! Keep it up
@alexgrowsfoodАй бұрын
Thanks Vin. Tbh it would depend so much on the soil and distance from the water table and my patch of ground isn't consistent enough. I was really just after evaporation data for some simulations I was running. If I get them working I'll see if I can do something on water content and try and apply it to different soil types
@deestrawser2423Ай бұрын
Great content! I've been using grass clippings since the 80s and they have always been the best option for my garden. Gardening is expensive these days so free grass and less watering is a win/win. It's also good to find a KZfaqr that isn't trying to sell us something we don't need. Best wishes for you and your garden.
@alexgrowsfoodАй бұрын
It's amazing how good the free option is, isn't it? I had expected compost I bought in to do the job for me when I set up the garden but it was a tough year. I'm not the greatest at making my own compost so this is the perfect use
@leahcimwerdna5209Ай бұрын
I just chop and drop
@alexgrowsfoodАй бұрын
Love it! I've just lost my drying area so I'll probably be doing the same too. Saves a step...
@robertpowser5624Ай бұрын
It's not a coincidence that the best performance came from the finer ground materials. I use double ground mulch in my beds and it's about 3 inches thick, you do need to look at PH values as tanick acid from bark can be a problem but a bit of lime will help. Enjoyed video.
@alexgrowsfoodАй бұрын
Thank you so much! Possibly... The compost was a weird mix of sizes really but parking that for a moment, with the true mulches it seems like you're right. Better packing factor and reduced airflow to the soil.
@YotacivАй бұрын
Grass will clump and stop water infiltration…
@alexgrowsfoodАй бұрын
Possibly, especially if packed densely. Although significant water application should still seep through and the other materials have their own issues with top watering too. I recommend watering underneath anyway