Gardening by Mistake

I’ve got to clear up something that drives me absolutely nuts. Many people refer to “worm tea” but they are actually talking about leachate. The two are not the same thing and are not interchangeable. So what’s the difference?

Worm “tea” is better called “vermicompost tea” because we’re brewing the vermicompost and not the worms themselves. It is made from finished vermicompost or worm castings.

Leachate, on the other hand, is that liquid which may drip from your stackable worm bin system. That tells you that your bin has more liquid in it than it needs. A worm bin that is too wet can easily become anaerobic. It’s important to know that the leachate likely contains harmful compounds as well as helpful. For instance, anaerobic decomposition produces alcohols and other things which are toxic to your plants. These can be present in the leachate. The problem with the leachate is that you just simply do not know what you are pouring onto your plants. Some people use it and like their results. My guess is that those people have systems which are well run and perhaps use the same inputs most of the time so that they get pretty much the same leachate each time, a leachate that happens to not be full of harmful compounds. There’s no way to know for sure, however, until you’ve poured it onto some plants. You won’t know if there are harmful compounds in it until your plants crisp up and die or show other signs of damage. Why risk it? If you do risk it, you’d be wise to dilute it a lot first or pour some of it onto a weed and see how it reacts before applying it to plants you value.

With vermicompost tea, you can be much more confident about what you are pouring onto your plants if you are using finished VC. The one exception I can think of to this would be a vermicompost high in salts. This might happen, for instance, if chicken feed containing salts was used as the primary food source. Over time, that salt content is going to built in the VC and it’s possible it could end up at a high enough level that the tea could be too salty for the plants.

Early results are very positive in my trials. I’m using aerated vermicompost tea in my attempt to keep my roses black spot free, or at least mostly black spot free.

On June 7th, I took pictures of about 40 of my roses, most of them the worst cases of black spot. Then the next day, I started spraying them with the tea. So far they’ve been sprayed with AVCT 3 times. Some roses don’t look much different, two might actually look a little worse, but then there are the rest which look like different rose bushes. Some of my roses are black spot magnets, and they are looking beautiful. The changes in just 3 weeks are quite remarkable. At the end of the season I’ll post final conclusions and some before and after pictures. I’m looking forward to seeing how the roses look at that point.

I’m sure just about every gardener is aware of the fact that our waters are chlorinated. Worse, they might contain chloramines. Why is that worse? Chlorine can off-gassed, either through letting the water sit for a day or by running an air bubbler in it for an hour. Chloramines don’t dissipate that easily. To remove chloramines, you have to use other methods.

One method is to use a few drops of a dechlorinating liquid for aquariums. They handle both chlorine and chloramines. I thought this was a great solution for me. I could throw in a couple drops per gallon of water and get going on my aerated vermicompost tea.

Well… think again. I’ve recently learned that these drops are at levels that are well below harmful for aquarium fish, but they are still lethal to microbes. So using them is setting up an aerated tea of any kind for failure, or at least a lot less success. I imagine that enough microbes could be added at the start to overcome the chlorine removers, but I have no idea how much would be needed.

Dr. Ingham, the leading scientist in the field of microbiology in soil science, has a solution to this: humates. Add a very small amount of humic acid or humates to the water prior to adding the microbes you want to brew as a tea. The humates negate the chloramines. Then you can proceed as usual. The nice thing is that the humates are good for the soil and plants as well as being a fungal food for any fungi in the tea you are brewing.

While I have not read where Dr. Ingham has said anything about this, I imagine that in place of the humates a small amount of vermicompost could be added since, after all, worm castings are largely humus. However, to be certain that the chloramines have been negated, use a liquid humate.

I was determined to get to the garden and spray some AVCT yesterday evening. I couldn’t believe it when clouds started to fill the sky and a check on the radar showed big storms headed our way. There wasn’t supposed to be much chance of rain. Ha! No waiting for evening, then, to do my spraying.

I grabbed my sprayer (made more difficult by the fact that my son had moved it and I didn’t know it– I thought I was losing my mind when I couldn’t find it) and got it loaded up. I debated about straining the tea before putting it into the sprayer. Last time, I used a coffee filter, but that took a long time. This time, I used a wire mesh strainer. I didn’t think the strainer had very large holes, but apparently I was wrong and that wasn’t fine enough.

Yes, I saved time loading the sprayer, but I more than lost that time in the garden as I had to repeatedly take off the sprayer head and clean it out. Once I even had to clean out the tubing that sucks the water into the sprayer. I got to know this new sprayer real quickly. So call this a learning experience. Next time, I’ll take the time to strain better than what the mesh strainer does. (I need something that’s a compromise between coffee filters and the strainer. A coffee filter filters out fungi, which I want in the tea).

At least I got it sprayed in time for it to dry before the storms once again sent flood waters through my yard.

One nice thing about being out there, a bonus for my work: I got to see my first oenothera missouriensis (Missouri primrose) bloom from a WS baby. It was wonderful— huge and a very bright yellow (a pure yellow; not an orangey yellow). I wish I’d grown more now. I’ll be sure to do so when I WS next time.

It’s been a busy week in the garden and I haven’t been inside much to be posting to the blog. I applied another AVCT soil drench and I’ve gotten a lot of weeding done and after the 4 inches of rain in a little over a day, I began putting down a thick newspaper topped by leaves mulch to trap that moisture in (and stop the weeds, of course). It’s raining again now (we’re supposed to get another several inches this weekend– we’re sure going to wish we had this come late July!) and again, once it stops, I’ll be out early next week taking care of another bed. Of the 4 beds in the rose garden, I will only mulch 3 (if I have enough leaves to get that far). The other still floods with a current when it rains much. Until I get that fixed any and all mulch washes away.

In the meantime, I’m scouring the web for information on AVCTs and CTs.

I’ve done a lot of reading lately about compost and vermicompost teas being used effectively to fight black spot in roses. Before this season started I’d already started saying goodbye to my roses because I’d made the decision I was no longer going to spray those nasty fungicides. Every time I did it, I felt horribly guilty. And I worried about my own health. So, if I wasn’t going to spray, then black spot was going to run rampant and gradually, over the next 2 or 3 years, my roses would weaken and die off.

Just recently I thought to research if AVCT could fight black spot. I was elated to see that it can. That’s all it took to send me running for my bucket and air pump and bubblers.

I made my first batch of AVCT last week and applied it as a small soil drench. I wasn’t happy with the bubble action from my airstones, so this weekend I went out and got a pump with a huge capacity (thinking I may have more than one batch going at a time, at some point in the future), and a bunch of airstones, different kind this time.

I started up a new batch of tea Sunday night. Woah! What a difference some good airflow makes! Seeing the difference, I think that the tea I applied as a drench Saturday evening wasn’t as effective or potent as I’d hoped. It did not smell bad, so it’s not likely I did them any damage, but I certainly didn’t have that tea loaded with as much microbial life as was possible. So I don’t think it’s going to have any effect on the study I embarked upon Monday.

I wandered through the 4 rose beds and picked out some roses I want to watch over the course of the summer. I took pictures of them as they are now, black spot and all. I wanted a record of their size and their disease state. I’m hoping that by the end of the growing season there will be a clear improvement in the health and size of the roses.

I want to note one thing: I’m already waaaay behind on the disease treatment, even for a chemical regimen. The disease is already well established on many plants. So any improvement at all will be doubly impressive. It’s one thing to prevent black spot from getting established, but it’s another thing entirely to fight it off once it is established and it has grown into the tissues of the rose bushes.

I’ll post some follow-ups as the season progresses.

I’m hoping to be able to demonstrate that AVCT is an effective way to treat roses for black spot (Diplocarpon rosae). I suspect it is most effective in preventing it. Treating it once established is not easy, regardless of what is used– even chemicals.

My roses are going to be a real test of AVCT. I am going to track how some of my roses are doing over the course of this growing season. I have not sprayed anything yet this season and my roses are showing it. Some, poor things, are already defoliated. That was the depressing part. Actually, the really depressing part is how many roses I’ve picked out to monitor. Some I’m monitoring not for black spot but just to see how their mass increases overall.

I’ve got a big batch of fungal AVCT brewing right now. I can’t say for sure it’s as awesome as I think it is without examining it under a high power microscope, and I don’t have one. But other indicators promise that this is a great batch. I’m eager to get it applied and get the AVCT test underway!

Yesterday evening I started brewing a batch of AVCT (aerated vermicompost tea),  my first batch this season.

At 7:15 this evening I realized I’d better get a move on with the tea spraying. I grabbed my sprayer for the first time this year, opened it, saw the residue at the bottom and said, “Oh crap!” I’d forgotten one tiny detail: I can’t use this sprayer. Doh! This sprayer was used to spray mancozeb and other heavy-duty anti-fungal chemicals on my roses last year. Putting my microbial-rich tea in that would be an exercise of stupidity since it would kill them. So, I need a new sprayer. Dang it!

Well, spraying was out. So I had a choice: I could let the tea brew another day or I could apply it as a drench. I chose drench. I used a 1:5 ratio so my 3 gallons of tea would make 18 to apply. I added a couple of additional substances (like liquid kelp) and carried it out to the garden in 2 1/2 gallon batches. It took 7 trips like that. That might not sound like a lot, but my garden is far away. And each trip it seemed further. Next time I’m going to be smarter and take the tea and a hose out to the garden and do my diluting in situ. That would save a lot of time and effort. I didn’t have that brilliant idea until after I was done tonight, of course.

I didn’t have enough tea for all the plants, so only my roses got it, and I didn’t have enough for any roses outside of the rose beds. But those roses got 24 ounces apiece, except for some really small minis which got 12 ounces. If I could have, I would have given them each quite a bit more, at least a gallon apiece.

I’m disappointed that I didn’t get to do the foliar spray I’d planned on, but this tea and effort was not wasted by any means.  It feels good—very good— to have it done now.  Next time, hopefully, I’ll do the foliar spray. Just have to remember to get a new sprayer first!

I’ve got a fair amount of vermicompost accumulated. I’ve probably got 30 gallons in the garage and another 15 I’ve just set aside, and of course my herd is busy producing more all the time. It seems like a wealth of VC— unless you want to spread it on top of a garden in any thickness.

So what can I do to make the most of the vermicompost that I have?

I recently read The trophic diversity of nematode communities in soils treated with vermicompost. This study found that vermicompost applied to the soil had significant positive effects, particularly in reducing the number of plant parasitic nematodes and an increased yield. This likely isn’t news to any gardener who also vermicomposts. I crunched some numbers to turn their hectares and meters into square feet. At their lower rate of 5 t / ha, it turns out I’d need twenty-six pounds of vermicompost just for one of my beds. Good grief. Suddenly 45 gallons of VC doesn’t seem like so much.

But 45 gallons of VC is a veritable fortune when it comes to making vermicompost tea. At a cup per gallon of water used, a gallon of VC can make 16 gallons of tea! And a gallon of tea can go a tremendous way if it is applied as a foliar spray. Obviously it doesn’t stretch as far as a soil drench unless it is diluted if needed to make it go further. It simply means fewer microbes being applied per volume of water than when it is not diluted.

Clearly, for me and for many, vermicompost tea is the way to go. Now, there are a few very significant differences between applying vermicompost directly to the soil and applying it as a tea. While properly brewed VC tea contains far more microbes than the vermicompost itself, there are some components of the vermicompost that won’t transfer or multiply in the tea. Vermicompost contains auxins and other plant growth hormones which are very soluble. They will be in the tea once brewed, although they will not be multiplied as the microbes will be.  Vermicompost has qualities that make it a good soil conditioner and it absorbs water much more quickly than soil, so there are also a strong arguments for applying the vermicompost to the soil around plants.

The cool thing about making vermicompost tea, is that you can do both! Once you have brewed your tea, you can then apply the “spent” vermicompost around plants.

I may not have 100+ pounds of vermicompost to apply around my garden (I need to weigh what I have just to see, realizing of course, that the weight of the vermicompost varies depending on how much moisture it contains), but I can do a whole lot with the amount that I have.

I should note, too, that just because one study finds a particular application rate works doesn’t mean that there are not benefits to applying it at a lesser rate. The aforementioned components of vermicompost will still be beneficial, but perhaps not at the same degree as if applied at a heavier rate. A second note: more VC is not always better. Multiple studies have found, for instance, better growth rates of plants grown in soil mixes with as little as 5% VC compared to using 100% vermicompost.

Wednesday, May 14, 2008

I sprayed my first batch of AVCT (aerated vermicompost tea) on the garden plants today. My goal is to spray them once a week. I’ve taken a couple pictures of one rose bush which is already plagued with blackspot. I’m curious to see if spraying with the AVCT regularly will reduce the blackspot at all. Since I won’t remember exactly how the plant looked tonight several months from now, I took pictures to compare to the bush at the season’s end.

The sage hasn’t bloomed yet. I guess it’s going to take longer than I thought. I’m impatient to see it bloom. And that particular bed could use some blooms.

Oddly, it looks like my first rose bloom this year will be Cherry Parfait. Not what I would have guessed.