Author: chogan@directresearch.com

G23-041: No-dig potatoes in leaf mulch. Poor yield.

 

This is just a note in another garden failure.  I won’t be trying no-dig potatoes in leaf mulch again.  I’m going back to planting potatoes in dirt.

Edit 2/10/2024:  After seeing a near-identical failure on YouTube, by master gardener Mark Valencia (Self-Sufficient Me), I’m pretty sure that the problem was heat.  Potatoes do not like heat, and excessively warm soil produces few, small, knobby potatoes.  That describes his yield and my yield, despite the fact that his pests, soil, leaf mulch and potato varieties have nothing in common with mine.  (I am in Virginia USA and he’s in Queensland Australia.) What we have in common is a hot climate.  Too hot for potatoes at mid-summer, in both places.  I’m guessing that a thin layer of dark leaf mulch, plus Virginia/Australia sunshine, allowed the tubers to get too warm.  I also note in passing that Ruth Stout — the U.S. popularizer of no-dig gardening — was a New Englander.   

The failure in brief

This year I tried growing no-dig potatoes using leaf mulch.  Three varieties, planted with minimal effort and zero forethought, on 3/17/2023 (Post G23-016).

The russets were a near-total failure.  Lucky if I managed to get back the three pounds I used as seed potatoes.  But russets basically won’t grow in the South, owing to their need for a long growing season.  So that was no particular test of no-dig using leaf mulch.

I dug up the rest of my potatoes this morning — reds and golds — and the results weren’t much better.  I’m guessing from six pounds of potatoes planted, I might have gotten 15 pounds of potatoes back.  Almost all are small.  Many are misshapen.  I suspect some of those are going to be unusable.

Tellingly:

  • The leaf mulch had shrunk down to about 3″ in most places
  • There were only two full-sized potatoes.
    • Both had dug themselves into the ground.
  • Several potatoes had rotted.
  • Several were misshapen.
  • Several had visible insect damage.
  • There was considerable insect activity in the leaf mulch.
  • The potatoes were as dirty as if they’d been grown in dirt, to boot.

My conclusion is that, for a lot of reasons, my local municipal leaf compost is not a good medium for growing potatoes.

By contrast, growing no-dig potatoes in straw, two years ago, worked reasonably well.  Yield was less than for potatoes grown in dirt (which I think is an established fact).  But I got a good lot of full-sized, good-looking, clean potatoes (see Post G21-052 for details).

If it were not for the cost of straw bales in this area, I’d go back to growing no-dig potatoes in straw.  As it stands, I’ll be going back to growing potatoes in dirt.  I’m not going to try leaf mulch again.

Post G23-040: Radiative cooling experiment, a puzzling worse-than-total-failure.

 

This is a simple controlled trial of whether I can get a few degrees F of “radiative cooling” in my raised beds, using radiant barrier.  See a few posts back for details.

In a nutshell, total failure.  And I have no clear idea why.

Continue reading Post G23-040: Radiative cooling experiment, a puzzling worse-than-total-failure.

Post G23-039: Eats, shoots, and leaves. When to harvest mustard, decoded.

 

I’ve been having a hard time determining when and how to harvest mustard.  Seems like mine goes from green, to shattered (broken, empty pods), with nothing in-between. If I follow typical internet garden advice and let it stand until its completely dry, I’m not going to have any seeds left.

To hedge my bets, I cut down about a third of my plot of mustard a few days back.  It’s now drying in the sun.  But from the looks of it, above, I may have been too early.  That still looks awfully green.

The best description I found of what I’m supposed to be looking for, if I want to “swath” my mustard (cut it before it’s fully dry), is from North Dakota State University

Mustard should be swathed following general leaf drop when overall field color changes from green to yellow/brown and early enough to avoid shattering.

To determine physiological maturity, select pods from the middle of the racemes of several plants in areas representing the average maturity of the field. Most varieties are at the optimum maturity for swathing when upper pods have turned and seeds are brown or yellow. The remaining 25% of green seeds will mature in the swath prior to harvest.

Much of that makes sense.  Look for leaf drop.  Got it.  Look for the field turning from green to gold.  Fine.  Now check a bunch of pods that represent the median of what’s in your field.  That is, seed pods in the middle of the stem, on plants of average maturity.

Then I lost it.  I could not make head or tail out of this phrase:

” … when upper pods have turned and seeds are brown or yellow.”

But, on mine, the pods at the bottom turn brown first.  Which makes sense, because those would be the first to flower.  If I wait for all the upper pods to turn (from green to gold), I won’t have any seeds left.  And since this description was written for the types of mustard that shatter easily, I know that’s not what it’s telling me to do.

After about my twentieth re-reading, I finally got it. 

Not “upper pods” meaning the ones at the top of the plant.  “Upper pods”, meaning, for the test pods, the end of the pod that attaches to the plant.  That end of the median pod should be golden.  It’s OK if the rest of the pod is green, as long as the seeds are fully-formed, and most (75%) are brown.

Re-written:  Harvest when the median pod, on the median plant, is starting to turn golden, at the stem end of the seed pod.  And when, after splitting the seed pod, most of the seeds in the pod are golden.  At that stage, as long as the rest of the seeds in the pod are fully formed, they’ll turn from green to golden as the plant cures.

Below I have a seed pod that’s almost right.  The upper pod — the part attached to the stem — is brown.  The tip is still green.  And, while you can’t see it, the first couple of seeds in the pod were, in fact, yellow.  And all the seeds are fully-formed, that is, full size.  That should mean that all the green seeds shown here would have gone on to ripen to gold, if I’d cut that plant down at this stage.

That’s still a bit too young, from the criteria above.  I ought to see yellow seeds down most of the pod.  But even at this stage, the pod was already starting to shatter (separate).  So it’s possible that I have to harvest at this relatively green state, and hope for the best.

Conclusion

I think this all fits now.

If you have a mustard that doesn’t shatter, you can just wait until the whole field turns brown, and harvest it.

If you have one that shatters — where the seed pods split once they turn brown, as mine has been doing — you can’t wait that long.

Instead, you’re going to have to harvest it partly green.  That inevitably means harvesting seed pods that are in a wide range of maturities.

Determining what “partly” means is the tricky part.  So you pick the point at which the median seed pod in your field is just ripe enough that it will continue to ripen after you cut it.  That means that the top (stem end) of that pod is brown, and most (but not all) the seeds in those median pods have already turned brown.

Post G23-038: Tomato non-ripening and a radiative cooling experiment.

 

Non-ripening tomatoes and nighttime temperatures

In 2020, we had an extended period when tomatoes would not ripen.  That was new to me, but apparently that’s pretty common in the South.  The lack of ripening is due to excess heat.  But it’s not a daytime excess.  It’s due to warm nights, as many varieties of tomatoes will not begin the ripening process (enter the “breakers” stage) if nighttime temperatures consistently exceed 70 or maybe 72 F.  See Post #G22-43 for full details.

Source:  Calculated from historical weather data from NOAA, for Dulles International Airport.

As explained in that prior post, the non-ripening is a subtle thing.  Tomatoes that have already begun the ripening process will continue to ripen.  But those that have not yet started that will remain green.  So, at some ill-defined lag after the nights warm up, the supply of ripe tomatoes gradually dries up.

That “warm nights” thing is a pity, because climate models have long predicted that global warming will raise nighttime temperatures more than daytime temperatures.  So it would seem that warmer nights are in the pipeline.

If you look at the graph above, that 2020 stretch of warm nights began in the middle of July. 

Here’s the extended forecast for Vienna VA today:

It’s worth pointing out two things.

First, we’re surely in for at least a few nights above 70F.  And, depending on whom you believe (and your misplaced trust in 10-day forecasts), we might be in for an extended period with nighttime temperatures over 70F.

Second, it won’t take one whole lot of warming to push all those forecasts above the 70F threshold.  That’s going to make it tough to grow a whole lot of varieties of tomatoes around here, I think.  But we’re likely talking the better part of a century from now.  I hope.

Everybody talks about the weather, but nobody does anything about it:  Radiative cooling.

Not me.  I’m going to try a radiative cooling experiment.  I’m going to see if I can use radiant barrier to reduce the nighttime temperature in parts of my garden.

It’s an unusual idea, but it’s not rocket science.

As I noted in earlier posts on this topic (G21-014 ,  G21-015 ,  G22-005 , etc.) a garden bed is like a big window, looking straight up into outer space.  As such, it continuously radiates heat energy (long-wave infrared) upward, toward the cold of outer space.  By my calculation, on a cold spring night, you lose more heat from radiation than from conduction.

That’s why a radiant barrier is what you want, for frost protection, for your garden beds.  That can be a space blanket or similar material.  But that’s also why a glass cloche works to prevent freezing overnight.  And why a simple, thin-walled glass mason jar provides excellent frost protection for tender plants (Post G22-006).  And, by contrast, why polyethylene sheeting does diddly-squat to prevent overnight freezing (G22-005).

But, weirdly enough, you can also use a radiant barrier for cooling, by preventing ambient radiation from reaching your garden bed at night.  In effect, you make it so that your garden bed “sees” only the cold of outer space, directly over head.  If the air is sufficiently transparent to long-wave infrared, your garden bed then cheerfully radiates energy off into outer space, and cools as a consequence.

This technique works OK in the dry desert, with a clear sky, which may explain in part why various Middle Eastern cultures have used it for millennia, to make small amounts of ice, in the desert (reference).  That said, even under those optimal conditions, temperatures had to be near-freezing to start with.  This reference suggest an upper limit of 5 C, or about 41 F.  Ideally, a combination of insulation, evaporative heat transfer, and radiative losses would generate small amounts of ice, under those conditions.

By contrast, the main problem with using that here is water.  Water vapor is the most important greenhouse gas.  It’s plentiful in the atmosphere, and it absorbs and re-emits infrared across many parts of the infrared spectrum.  Between the humidity and the clouds, a lot of what gets radiated into space will be, in effect, reflected (re-emitted) right back down to earth.

Which is, in a nutshell, the greenhouse effect.

OTOH, I only need a few degrees.  If this can pull a 9F differential in the dry desert, maybe it can drop the temperature 3F on a cloudless Virginia summer night.  After all, I’m just trying to trick those tomatoes into starting the ripening process.  My understanding is, once that gets going, they will continue to ripen.

So it’s worth a shot, just out of intellectual curiosity.  I’m going to set up a small enclosure made of radiant barrier — basically, a big tube with the open ends facing ground and sky.  Cap that with a piece of clear polyethylene sheet to provide an IR-transparent barrier to the outside air.  Then use temperature loggers to track nighttime temperatures inside and outside the enclosure.   I might get lucky.

Otherwise …

The nice thing about this method is that there’s zero energy consumption.

Probably ought to consider a shade cloth, as well, but I can’t quite figure out how that would be much help in terms of nighttime temperatures.  Plausibly, the cooler the soil stays during the day, the cooler the area may be at night.

But if I’m willing to expend a bit of energy, I think a mist-cooling device would plausible achieve a sufficient drop in temperature.  Mist coolers work by converting sensible heat (temperature) into latent heat (water vapor, instead of liquid water).  I went over that in my post on the true energy cost of humidifiers, Post #1669.

That said, bathing my plants in mist all night just seems like a recipe for every tomato leaf disease known to mankind.  So that’ll only be used as a last resort.

Otherwise, short of sticking a window AC under a tarp, and using that, I guess I’m at the mercy of Mother Nature here. If it’s too hot to ripen tomatoes, then it’s too hot to ripen tomatoes.  Grow something else for the time being.

Any sufficiently advanced technology is indistinguishable from magic.  (Arthur C. Clarke)

My garden beds emit “black body” radiation.  That is, they toss out radiation at every frequency, with a peak in the long infrared.  As a consequence, some of that is bound to be absorbed and re-emitted by atmospheric gasses.

But suppose, through some miracle of modern science, you could create a material that radiates infrared only on those bands of frequencies where the atmosphere is transparent to infrared.  That is, frequencies that aren’t absorbed and re-emitted by common atmospheric greenhouse gasses.

Then — and frankly, this is where I lose it — you could, in theory, create a material that would literally cool itself below ambient temperature.  If the air outside is 80F, your miracle-o’-modern-science could be 78F, with no power input.  Just from enhanced “emissivity” in the right part of the spectrum.

Or, as these folks put it, emphasis mine:

... the PDRC coating demands a significant solar reflectance (Rsolar) in the spectral region (0.3–2.5 m) and a significant thermal emissivity (LWIR) in the environmental long-wave infrared (LWIR) propagation region (8– 13 m). As a result, during the day, the energy loss to frigid space ... is far more than the warming from daylight, resulting in electricity-free spontaneous refrigeration.

In other words, you could sit a piece of this stuff out in the sunshine, and it would remain cooler than the ambient air.  With no energy input.

That’s close enough to magic for me.

Post #1810: Top 25 AIs for fill-in-the-blank? When did this happen?

Let me say that I don’t ever use a grammar checker.  My wife refuses to use spell-check.  Says she, “I think that an educated person should be able to write clear English.”

Yet, on a lark, I decided I’d have an AI write my next blog post.

Still working on carrying through on that.  It ain’t as easy as I thought.

Continue reading Post #1810: Top 25 AIs for fill-in-the-blank? When did this happen?

Post 1808: Some thoughts on AI, part 1.

 

AIs of various sorts seem to be able to do a lot of jobs that traditionally required the use of a human mind.  They are particularly good with text generation.  They can also easily do “literature reviews”, to offer a summary of current understanding or thinking regarding a topic.  Some say they are good at writing computer code, but I’d like to see evidence of that before I’d believe it. Continue reading Post 1808: Some thoughts on AI, part 1.

Post #1807: Sous vide chicken breast via Shake ‘n’ Bake.

 

In a nutshell:  A large pot, a small burner, a thermometer, and some plastic bags.  That’s all the equipment it takes to do up a batch of sous vide chicken breasts.

The bags have to be food-safe.  I used heat-seal bags and a vacuum sealer.  But I’m told you can use Zip-locks.

Background

On my last trip to Safeway, they had boneless, skinless (tasteless, soulless) chicken breasts on sale.  Cheap.

I bought a pack, even though this is not a cut of meat that I prefer.  Seems like chicken breasts always turn out dry, no matter what.

I got the notion to cook them sous vide, that is, cook them in sealed plastic bags immersed in hot water.  Sous vide has a reputation for cooking meats perfectly, and for preserving both tenderness and juiciness.  Given how difficult is to get a juicy cooked chicken breast, this seemed like a good approach.

There were a few little drawbacks.  First, sous vide is French (under vacuum).  Second, it’s trendy.  Third, it’s the sort of thing that “foodies” do.  Whereas I just want a decent-tasting chicken breast, however arrived-at.  Just not in my wheelhouse, generally speaking.

But the biggest drawback is that I don’t have a sous vide cooker, and I wasn’t going to buy one for just one meal.  For sous vide, you need to keep the water at whatever temperature you want the fully-cooked meat to be.  In the case of chicken, that’s going to be somewhere around 140-145F.  A sous vide cooker automates the task of temperature control by combining a thermostat, a heating element, and a small water pump in a single unit.  Stick it in a pot of water, dial in the temperature you want, and it’ll do its best to keep the water at that temperature.

Martha Stewart to the rescue.  She says that one may do perfectly acceptable sous vide cooking without the fancy equipment.  Just use a large pot of water, a small burner, and a thermometer.  On a gas stove, regulate the flame to maintain a constant temperature in the water bath.

So here goes.

Sous vide cooking:  First, do no harm.

Job 1 is avoiding food poisoning.  See the section on cooking times, below.  The sous vide chicken recipes I looked at were not specific about times and temperatures, giving broad ranges.  If I had just naively used the shortest time, that might not have turned out well.

In short, food safety considerations put firm minimums on the time and temperature.  No matter how loosey-goosey any particular recipe is written.  Anything beyond that the minimum dictated by safety is at your discretion.  But safety first.

That said, I’m using quart vacuum seal bags and a Nesco vacuum sealer, below.  Martha Stewart assures me that I could do this with Zip-lock bags instead.

  1. Place a large, shallow pot of water on the stove to heat.
  2. Turn down a “cuff” at the top of a one quart freezer bag (to keep the eventual seal area from getting dirty).
  3. Place your dry spices of choice in the bag.  Here, I’ve used a variety, from classic Italian herb mix to curcumin.  Plus a bit of salt.
  4. Slip the chicken breast in the bag, grab the top with a clean hand (or paper towel), and shake to distribute spices.
  5. Seal.  Even though the raw breasts are a bit wet, they can be sealed on the normal (dry) setting.
  6. Regulate heat so that the water temperature is what you want.  In my case, about 145F for chicken.
  7. Place the bags in the water.
  8. Briefly turn up the heat, to return the water bath to the desired temperature.
  9. Move the pot to the smallest burner on the stove.
  10. Turn burner to low, to maintain desired temperature.
  11. Check temperatures every ten minutes or so, adjust burner as needed.

Here are those five chicken breasts after the shake-and-seal step:

And in their hot water bath, circa 145F.

How hot, how long?

One unexpected aspect of sous vide chicken recipes is the wide range of suggested cook times.  For example, Martha Stewart gives a range of 1.5 to 4 hours.

Is that optional?  Can I pick any time within that range?  Is that the possible range, given how well I want it cooked?

In short, what does that broad range of times represent?

I’ve read at least four completely different explanations for choosing a particular cooking time, within that broad range.

One possibility is that the thickness of the meat determines the required cooking time.  So the stated range is for a variety of thicknesses of meat cuts.  The thinner the meat, the shorter the cooking time.

A possible alternative explanation is that it’s difficult to overcook meat with sous vide.  Thus, the range of times shows you the point at which the meat is done (i.e., safely edible), and the longest you can leave that fully-cooked meat in the cooker without damaging it.

A third possibility is that the longer it cooks, the more tender the meat gets.  Functionally, this is similar to the last one, in that the lowest listed cooking time is the time to the point where the meat is done.  The only substantive difference is that the meat becomes more tender, the longer it cooks.

The fourth is a straight-up food safety argument, that a certain cut of meat, at a certain temperature, will require some minimal time in order to be pasteurized properly.  That is, for any bacteria on or in the meat have been killed.  Note that this argument isn’t about the mouth feel of the cooked meat.  It’s a straight-up food safety argument.  (See this reference for a detailed chart of times).

Apparently, there’s some truth to all of the above.  You need to cook the meat long enough so that it’s done (i.e., tastes right).  You need to cook it long enough so that it’s safe to eat (pasteurized).  For both of those, thicker cuts do in fact take longer than thinner ones.  And the longer you cook it, beyond those minimums, for some cuts, the more tender the cut of meat gets.

All said and done, I like the chart from the reference cited just above, which would suggest that my roughly 1.75″ thick chicken breasts ought to cook for a minimum of 2.5 hours, at 145F.  That’s a straight-up food safety limit.  Anything less than that, and you are not guaranteed that all pathogens in the chicken will have been killed.

In this case, I get the feeling that the chicken breasts would have tasted perfectly fine after the minimum of 1.5 hours.  But based on the pasteurization chart, they would not have been completely safe to eat before 2.5 hours.

On second thought, let’s make it three hours even.  Just in case.

Three hours later …

Note:  I’ve now looked at this on my phone, and it looks terrible.  In person, it actually looks appetizing.

There’s the end result.  Chicken breast with Italian herb seasoning.  I snipped off the top of one bag, dropped it on a bed of rice, and cut off a small piece.

The results are good, by my humble standards.  The chicken breasts remained moist.

Pretty much everything else needs work. All of which would be solved by a good marinade, I think.

Unexpectedly, with Shake ‘n’ … to distribute the dried spices, followed by sous vide, the spices stay right where you left them.  That’s because the juices mostly stay in the meat, leaving next-to-no juices available to redistribute the spices within the packet, during the cooking.  Whatever got coated during the Shake ‘n’ Bake step remained coated.  Anything missed at that stage remains uncoated.

In particular, the entire interior of the chicken breast is uncoated, and so tastes like grocery store chicken breast.  Edible, but clearly a flaw from the outset, if you’re going with dry spices.  Yet, isn’t the whole point of the spices (or bbq sauce, or marinade) that you taste something other than bland industrial chicken breast?

If there’s a next time, I’ll cut the breasts in half and marinate.  Probably have to switch to Zip-locks at the same time, as vacuum sealing wet stuff is tricky.

Having successfully sous vided once, I understand the joy of having an actual sous vide cooker.  Much like a slow cooker, or a rice steamer, there’s something to be said for setting up an appliance to cook something, and having that appliance do the rest.  Rather than test and adjust every ten minutes or so.

So, while I can do sous vide on the stovetop, if I did it regularly, I’d spring for an actual sous vide appliance.

On the final plus side:  No cleanup from the cooking.  Toss the plastic bags and you’re done.

 

Summary judgment.

I’m glad I didn’t buy the machine first.  So, thanks due to Martha Stewart.   Because this is probably still not in my wheelhouse.

Decent end result, too much of everything else.   Too much:

  • clock time.  Have I finally finally found a chicken-cooking method that takes longer than barbeque?
  • fuss.  Unless I move to Zip-locks and a dedicated sous vide cooker.
  • fossil fuel energy.  I get to keep the water warm, then air-condition that warmth out of the house.
  • single-use plastic.  For long-term storage, sure, I’ll use those bags.  For dinner, frequently?
  • prolonged intimacy between hot food and hot plastic.  Food safe plastic notwithstanding.

And, to be honest, at the end of the day, it’s still just a grocery-store chicken breast.  Seems like if I’m going to all this trouble, I ought be cooking something nicer.

Extras for canning experts.

If you’ve done some canning — and in particular, if you’ve ever done low-temperature pasteurization of pickles — surely you have to be asking yourself “are unopened vaccum-sealed sous-vide-cooked packages shelf stable?”.

Or words to that effect.

In other words, what would happen to these if I didn’t stick them in the fridge?

First, I’m sure they would eventually be unsafe to eat.  Why?  Because chicken can be canned at home and the UDSA Complete Guide to Home Canning says that chicken, already partially cooked, needs to be processed for 90 minutes in a pressure canner.  They don’t even give a time for open (water-bath) canners.

So that’s about 90 minutes, at about 250F, for safely canned chicken.  Compared to which, three hours at 145F clearly doesn’t cut it.  There’s no way these are shelf-stable food.  And, in fact, by direct testing, botulism spores survive sous vide treatment (reference), which means these are not safe to store on the shelf.

Second, that said, sous vide may provide a longer life on the refrigerator shelf. USDA says storage up to four weeks, at refrigerator temperatures (reference).  But other references disagree, and suggest that sell-by dates for commercially-prepared and refrigerated sous vide products may not be conservative enough (reference).

Bottom line:  It’s best not to count on this as being any sort of food-preserving technique.  Store it and consume it as you would any cooked meat.

G23-037: Eastern Boxelder Bug.

 

Another gardening year, another invasive pest.

This year, I’ve seen a few cucumber beetles and a few Japanese beetles.  And that’s about it, for garden pests.  In particular, I haven’t seen a squash vine borer.  Then again, I gave up on planting summer squash.  Due to the squash vine borer.

And then there’s this thing, above.  This, by contrast, seems to be all over my garden this year, chowing down on a wide variety of plants.

Based on Google image search, this is a nymph (immature stage) of the Eastern Boxelder Bug, Jadera haematoloma.

Which is a bit odd, really.  Apart from never having seen this one before.

There are no boxelders near here.  At least, none that I have ever noticed.  And I do notice them, because the leaves of the boxelder are a dead ringer for poison ivy.  Having grown up roaming fields and woods in Virginia, poison ivy is one of those things that’s now hard-wired in my brain.

But as an alternative host, they like silver maples, and those we have in abundance.  Some very large silver maples have been in the process of dying off, a few hundred feet up the road from me, and I wonder if that has displaced some population of eastern boxelder bugs.

At any rate, the consensus of opinion is that these are mostly harmless.  They feed by piercing and sucking, but nobody seems to suggest that they do a lot of damage to garden plants.  And, unlike hard-shelled beetles, these are easily killed by a simple soap-and-water spray.  So if they get out of hand, there is (at least in theory) an easy control measure.

So, for once, I’ll go the live-and-let-live route, for this latest garden pest.  At least it’s a native species, and at least it doesn’t normally cause much damage.