Micro Greens- Yield Per Tray

I'm looking into the feasibility of growing micro greens for winter income, as a stepping stone project to avoid having to find conventional work in the cold months.

Does anyone know the approximate yield of microgreens from a typical plastic seeding tray (38cm (15") x 25cm (9.5") x 5cm (2") deep)

For arguments sake, lets say I'm growing arugula or turnips under double ballast 40 watt flourescent bulbs.

Also, any tips and tricks from seasoned micro green growers would be appreciated

bump.

I'm interested in this too. If anybody has experience with microgreens, I'm all ears.
William

Hopefully I'll be able to tell you in about a month. I juuuust started a micro green cycle on wednesday. I planted kohlrabi, komatsuna tendergreen, and arugula so far. I've got five sets of fluorescent shoplights currently shining down on 20 seedling trays in total. I'm planning on starting sunflower micro greens another five shoplight ballasts and two small ballasts that can have one tray under each. Hopefully I get that set up today. I'll post weight results if I don't forget.

If you have any spare 10 gallon containers you can grow some small root vegetables too.

So I just harvested my first micro greens cycle. I grew arugula, komatsuna tendergreen, and sunflowers, though the sunflowers weren't harvested yet. Here's a bit of a report:

I harvested at the stage when most plants had the first true set of leaves emerging. They were getting leggy and a 'very' few growing on the edges of the trays were starting to look wilty so I thought it was time to break out the scissors...

The best yield per tray was 7 ounces
I'm guessing the average for a well germinated tray (80% or more) is about 5 ounces per tray though it's hard for me to say because only a few of my trays had that good of a germination rate.

I think I overwatered some of the trays and the seeds rotted. They sure didn't dry out. Either that or I buried them too deep in some spots, though that doesn't seem as likely to me. My tray setup was like this...Top tray had holes in it, this tray had the soil and plants. Then I had a tray below that had NO holes. Below that I had a third tray with holes, which was there for support to help avoid getting splits in the trays that hold water.

If I do another cycle I think I'll do a few things differently:

I won't bury my seeds but will pre-sprout them and just spread them on the very top of the wet soil.
Then I'll cover them with another tray for a day or two until they take root and start actively growing on top
I will wet the soil before packing it into trays instead of watering the trays from the bottom after the fact. I think this is where I really fucked up.

Glad to hear of your good results! I hope that each run gets better and better. Consider grabbing a bag of perlite from the store and mixing it with your soil mix if you haven't yet, will improve aeration and might increase germination rates, and getting something around the sides of your containers will help keep the outer edges of the tray warmer, also potentially increasing germination.

Odd, I posted a reply to this awhile ago but I don't see it. Oh well, here we go again...

Thanks for the good will Julian. There is a fair amount of perlite and vermiculite in the mix. The germination was best on the sides of the trays. I think the problem was water pooling in the low spot down the middle of the tray, causing the seeds in that area to rot, not soil warmth. The air temperature in the room was at about 69 ferenheit during the germination period so that should have been adequate for proper soil temperatures.

Your welcome Travis

Indoor Gardening is a whole different ball game, you ARE Mother Nature . Indoors soil temps can vary vary from -20 room temp to room temp depending on how much you water. I'm not saying over watering wasn't the problem, just that it may not have been the only contributing factor to the lower germination in the middle of the tray. cooler temps+moisture=seed rot.

Pregermination is the way to go depending on what your popping, I find that beans generally don't like more than an over night(6- if any, peppers/tomatoes take 12-48, older seeds taking longer. I prefer the shot glass to the paper towel.

Before you put the other tray on top of the sprouts, consider sprinkling some myco-mix on them, maybe use soil instead of the tray if you use the myco-mix.

I had a thermometer placed very close to the trays, and checked each tray periodically to make sure their temp range was about the same.

I agree with pregerminating and do it for large seeds like sunflowers and peas but I can't see how it'd work for small seeds like arugula and turnip etc. When those seeds get wet I find they just stick to my fingers too much.

OK, I just like to bring less obvious factors up for consideration.

I use the Shot glass method. the general method is to soak the seeds in a shot glass of declhorinated water overnight on top of an appliance that is warmer than room temperature (refrigerator) and then drain the seeds onto a towel, then plant them. For small seeds I say forget the towel and mix them straight into soil and mix around till you feel satisfied that they are distributed evenly.

Julian: With mixing the seeds into the soil I'd be afraid of getting spots of heavy germination, and spots with no germination. I've had that happen to me trying to broadcast pak choi seeds on a garden bed and raking it in.



So I harvested a two trays of the sunflower micro's. I got a little over 10 ounces per tray BUT I don't think that weight is reflective of what one should generally expect. I waited longer than usual to harvest them, so they got taller than the standard height to harvest which means they had more mass and weight. I am guessing there'd have been about 8 ounces of weight from a tray that was at the standard height.

Travis, Have you found an outlet for your micro greens or are you still in the figuring it out stage?

Thanks,
Keith

I have a small local CSA and restaurant customer base that I would list to. I also am part of a regional group of farmers who sell to a farmer/distributor who sells a lot to restaurants in Toronto which is the biggest city around these parts. I don't see myself having trouble selling at a small scale but do you have any suggestions or were you just curious?

I'm not producing microgreens yet but I am interested and have others that are interested in growing them.
I was mainly curious if you had a market and if you did what the going rate was.

I have lots of worm compost waiting for spring so would have plenty of growing medium just not sure of the economics.
Any info on that end would be appreciated.

Thanks,
Keith

Around here micro greens sell at retail for about $16-20/lb. That price takes into account selling by the ounce and not just the pound. Wholesale I'm not sure but I imagine it'd be $12-14/lb. I read some study out of Florida that said the going rate was like $30-50/lb. Just another reason I wish I lived in Florida!

Dang, those are some pricey greens! You do your thing, I'm just tossing out ideas. I read somewhere that to help with even seed distribution someone mixes their seeds with sand and then broadcasts.

Glad to hear your sunflower greens did well! What is the next round gonna be?

I appreciate the input Julian, thanks.

I'm not sure what the next round will be. Beets and/or turnips probably. I've really just been using up old seeds that never made it into my garden at this point.

Ohhh! consider getting a deeper container so you can get some roots too!

1lb of spinach seed cost $11 http://www.mainstreetseedandsupply.com/Bloomsdale_p/vssb.htm
by the time you factoring shippig and handling possible taxes. its at least $15
Then there is the germination rate of 75% so its more like $20.
However the weight will increase by 4 so its down to $5

I did not however adjust for electric/water/soil/nutrients/equipment/labour/transportation/marketing/etc type of operating cost or taxes.
So the $30/lbs makes sense

Julian; do you know of a place that sells deeper trays? of the same length and width as a typical seedling tray?

S Bengi; Where do you get your seed pricing from? HAve you heard of Mumm's organic seeds? ... Mumm's

I make all of my flats (to fit whatever drainage trays I can come up with) using 1"X4" untreated pine boards for sides and 1/4" hardware cloth for the bottom. I then line with a layer of uncolored paper before adding my homemade planting mix. I add a strip of molding to the bottom edge all the way around for a gap between it and the tray for good drainge. They could easily be made deeper Mine have lasted several years and are still in good shape.

10 gallon rubber totes, 5 gallon buckets, pretty much any container you can drill holes into. If you wanna be super cool get some Fabric Pots! Always try to make your own planting containers. one of the local hardware stores puts 10 gallon rubber totes on sale 3 for $10 once in awhile, I've built a flow through worm bin, a compost bucket and next time they go on sale I'm gonna make some plant pots. also the liquor store around the corner sells the 5 gallon buckets they have left over from their deli pickles for $2, roughly 75 cents cheaper than from big box. When you go to restaurants, ask to see the manager/owner if they have any buckets going to the trash, see what was in it, if your cool with what the contents were, ask for them, same goes for hospitals, grocery stores, factories etc. I know for a fact that St. Johns Hospital in Detroit throws out a stack of buckets at least waist high every day, most of them had contained bleach. For the fabric pots just use google and research which one is best/ how to make your own.

Rubber totes can also be used as fish tanks for aquaponics,, or just raising fish indoors, whether they be bait fish, dinner, or pets. Make sure to be extra on top off things if you were to use a natural environment as you can only see fish from the top.

Also what Judith said. Seriously, it makes the whole process feel more outdoorsy, and the wood can hold extra moisture for you.

Ah see, since I'm trying this for profit I need to maximize yield and with round containers you lose growing space in the corners so that's out. Regardless, I have to use lightweight trays because my 3 tiered fluorescent light stand couldn't handle the weight of anything much larger than the generic trays

I replied the other day, must not have went through, probably my fault, was in a hurry.
Ok, I didn't even consider the loss of space from round containers, I'm used to working with whats on hand, or in walking distance . If your bottom tier of lights is over the floor you could use that for a deeper container. You can scavenge square plastic containers, it is just a little bit more difficult. You might even have spare containers, you just need to condense and label.

Travis there maybe issues selling your micro greens (Sprouts?) to the general public check with your local Ag agent or state Ag agency and see what they require sometimes all it takes is a small fee to register your place and an inspection, out breaks of any sort have got to be traceable so the they can be limited, if not our food supply would be at risk by the who cares i am not eating it i only grow it types,

reference the spinach recalls over the past decade, processing plant that wasnt kept clean

Not familiar with the term micro greens, so i googled it, sounds just like the term "sprouts" used by raw vegans. You can totally eliminate the soil, if interested in the technique contact me and we can start a thread if need be

regards Stark

Julian: I don't think I'd be able to adequately water a deeper tray with my sprayer, and it would mean that I'd have a staggered watering period instead of being able to do it all in one shot. I use the sprayer because though it's quicker; adding water to the bottom of the tray sometimes causes the trays to crack and break, while watering with a watering can caused a lot of splashing and mess on the floor. Unfortunately the sprayer seems to take the most time out of the three options to get the watering done.

Fm Stark: Thanks for the warning. That's been checked into and as far as I could tell, in my province all that's required for selling micro greens is a triple washing. According to a colleague of mine who grows sprouts (that receive no direct light, and aren't grown in soil) they require a certified kitchen for washing and packaging. I think the difference is that micro's are seen more like baby cut lettuce, and because the risk of salmonella with micro's is MUCH lower than sprouts.

Ambiguity indeed, wiki microgreens quote "Also surplus young sprouts removed thorough thinning, but then used for food may be considered microgreens as well." no wonder we have lawyers, one man's treasure is another mans junk, guess it all depends on who you ask or who is doing the inspecting

regards Stark

http://soilblockers.ca/soilblockers/Welcome.html

YouTube vid showing how they are used: http://www.youtube.com/watch?v=x-VMneNrm_4


What about using soil blockers and moving up in size as you need to?

It may be a small financial commitment at first but it will eliminate root bounding, the use of plastic containers and you can simply size up instead of transplanting.

Maybe someday Sophie but I have a lot of plastic trays that I got for free and I'm extremely strapped for cash so I'll use those until they fall apart, which many are starting to do.

Some friends of mine who live nearby have soil blockers and I really like the idea of em. I wonder though if they require more watering than a solid tray due to evaporation from the sides as well as the top.

For me transplanting isn't really something to worry about. I think that root bounding isn't really an issue with micro greens because they don't have a long enough life to build up enough of a root system. I harvest after about 20 days.

Doesn't sound like the thing for you then!

I don't have any myself (underemployed student for now) but am very interested in giving them a go. I had read somewhere that putting a cloche up works to lessen the evaporation but on the other hand, that doesn't eliminate the plastic :-/

I plan on eventually using soil blockers for spring starts like tomatoes/peppers etc. and for starting tree seedlings. Really excited for the latter because it'd mean the taproot will probably survive and not split when the trees get transplanted into bigger blocks.

Oh, yah! That's a good point on the tree seedlings!

I'm excited to give the blocker a go