Brewing large amounsts of compost tea

Hello Eric,

I’m growing a many varieties of potatoes, watermelon, squash, peas, cucumber, lettuce, cilantro, cannabis (for myself) , strawberries, carrots, and parsnips.

My largest crop is potaoes this season. I’ll plant a large amount of noble spinach in about a month as well as other late summer planted greens.  Next year I hope to have a 3-4 seasonal crops.

What is a good way to brew a large amount of compost tea in site in the field? I am thinking a clearly marked old water barrel with wheels may do the job nicely. If I shake it at least once a week would the compost tea be usable and aerobic or would I need to aerate more frequently? Or would a solar powered air pump be a better option for aeration?

What is a good way to brew a large amount of compost tea in site in the field? I am thinking a clearly marked old water barrel with wheels may do the job nicely. If I shake it at least once a week would the compost tea be usable and aerobic or would I need to aerate more frequently? Or would a solar powered air pump be a better option for aeration?

Hi Johnny,
Really interesting question for me this. I am glad you are growing such high value crops and congratulations on your potatoes. If you are growing cilantro you must like curries, no ?

Your traditional method will work and has been for generations but it doesn’t hurt to be armed with some extra science. As it stands it is semi-aerobic/semi-anaerobic. I’d be reluctant to put it on my leaves for eating but otherwise fine. Many aerobic organisms like consuming anaerobic things, humans included, although realistically this will be not be fermented so a little caution is suggested. If you put your week old semi-decomposed sludge around your plants it’s going drive your earthworms crazy, they love this kind of stuff. The anecics are known to prefer this over fresh organic material. They like dragging  it into their galleries to break down for a few days, rather like what you are doing.  A lot this organic matter is going to be microbially mediated before it gets to your plants. If it goes through the gut of an earthworm it is renowned for its cleansing properties and the casts awesome regarding fertility.

Adding comfrey is a good start but it occurs to me, why stop there ? Comfrey is good for potassium and phosphorus but you are missing one of the big three there – namely nitrogen. Chuck in some clover (N) and kelp meal (P, traces growth hormone) too. If you have time to let it break down use the abundant nettles and put your comfrey in a couple of weeks later.

If you prefer greater aeration, a safer and sweeter smelling mix you have a good idea with the solar bubbler.  There may a question of it getting pilfered and it now occurs to me with little gardening synergy you could also add the type of pond weed that produces oxygen.  You may need a container that has a broader base in relation to the height to get more sun in. With a raised pond shape you can get in more volume and you mentioned wanting to make lots of tea. A children's pond would do it but it's not very elegant or environmentally sound, guess this a permi design matter.