Category: Garden

Posts about gardening and related topics, such as canning and maybe other aspects of food preservation.

Post #1612: CO2 emissions from gas versus electric leaf blowers.

Source: Xerces Society for Invertebrate Conservation

To be clear, I think the right thing to do with your fallen leaves is to leave them alone, to the extent that you can (Post G22-034).  But if you’re going to use a leaf blower, how do gas-powered ones compare to electrics, in terms of generating C02 emissions?

Bottom line:  7-to-1.  At Virginia’s current electrical generation mix, a gas-powered leaf blower produces about seven times as much C02 emissions as an electric leaf blower.  I show the calculation below.

In part, that’s because the grid just keeps getting cleaner.  A couple of decades ago, the difference would have been more like three-to-one.  But mostly that’s because small two-stroke engines, as used on leaf blowers, are inefficient.

Note that this 7-to-1 ratio is just for C02.  In terms of total air pollution, gas powered leaf blowers stack up far, far worse compared to electrics.  In particular, smoky two-stroke gas engines produce huge volumes of unburned hydrocarbons, as anyone who has ever seen and smelled the exhaust from a two-stroke can attest.

To be clear, leaf blowers don’t use enough gasoline to matter, in terms of our annual C02 emissions.  They are a drop in the bucket.  And not that there aren’t a lot of other reasons to skip leaf blowers entirely, let alone gas-powered ones.  But this is a statistic that I wanted to pin down.  So here is the calculation, with citations as to source.

Background

My wife asked me a simple question today regarding gas-powered versus battery-powered leaf blowers.  How do they compare in terms of C02 emissions?  I did a quick back-of-the-envelope and got numbers that didn’t appear credible.  So I decided to do a more formal calculation, with the metric being pounds of C02 produced per 100,000 cubic feet of air moved.

It’s already well-established that gas-powered leaf blowers produced a tremendous amount of air pollution, per amount of work performed.  That owes mainly to the use of small two-stroke engines.

No shock there — these are the engines where you mix the oil with the gas, and burn that mixture to produce a smoky blue exhaust.  That exhaust is every bit as dirty as it looks.  You can look that up anywhere, and as far as I know there’s more-or-less zero disagreement about that.  Here’s what appears to be a fairly sophisticated test (reference Edmunds).

In terms of pollutants (e.g., unburnt hydrocarbons) and such, that’s the pretty much the end of the story.  Except to note that a part of the resulting air pollution is black carbon, which is increasingly being recognized as a major contributor to global warming (See Post G22-058).  So, these two-stroke gas engines contribute to global warming beyond their emissions of C02 alone.

But my question was in terms of C02 emissions.

In absolute terms, obviously, the gas consumed in lawn care is a drop in the bucket, compared to the gas consumed by cars and trucks.  (So, priding yourself on using an electric mower, while you drive an inefficient car, is straight-up greenwashing, in terms of impact on C02 emissions.  It might ease your conscience, but in the grand scheme of things, your lawn mower is rounding error in your household carbon budget.)

That said, just exactly how do the C02 emissions compare, between gas and electric leaf blowers?  My first rough cut seemed to say that gas leaf blowers produced vastly more C02, compared to electrics, than gas cars did compared to electric cars.  (Which, for a Prius, is about 2.5:1.  Gas miles in our Prius Prime produce about 2.5x as much C02 as do electric miles.).  So I decided to do a more careful and better-documented calculation.

A virtual trip to Home Depot, and a surprise.

I went to the Home Depot website and began with the first gas-powered leaf blower that showed up.  This is an ECHO gas-powered backpack leaf blower.  I downloaded the manual to see what I could find out.

My first shock was in finding that this can be fitted with air pollution controls.  For example, this model has a catalytic converter and a gasoline evaporation control system, at least in some areas.  This, apparently, is required by law, and has been required, in at least some areas, since the mid-2010s.

Source:  Manual for the ECHO backpack leaf blower referenced above.

I then looked at a similar Ryobi model, and it too has a catalytic converter as an option.  That said, the owners’ manual says that it must be replaced every 50 hours.(!)  Hard to find it labeled as catalytic, but it appears that the muffler assembly is a $50 part.  I’m guessing the average user will not bother to replace that after 50 hours of use.

Source:  Manual for the Ryobi backpack leaf blower cited above.

The important implication of this is that older comparisons — such as the 2010 testing done by Edmunds, cited above — may (or may not) be vastly out-of-date.  Those older studies predate catalytic-converter-equipped units.  It’s not clear to me whether all units are now equipped with catalytic converters, or whether the typical owner bothers to maintain those catalytic converters.  But this does make me wonder just how much all of the often-cited literature on the dirtiness of these engines is out-of-date.  I certainly see recent articles that still cite the remarkable findings of that Edmunds comparison.

It also appears that most of the advocacy articles focus on the high levels of unburned hydrocarbons.  That’s where the blue-smoke-spewing two-strokes do the worst.  All of them also seem to add in a huge amount of spilled gasoline, though how they could possibly know the average spill rate for the average consumer is beyond me.

Anyway, catalytic converters on two-stroke leaf blowers — that was news to me.  (Though if you Google it, you can find many examples.).  Maybe I’ll investigate further at some point.

For now, I’m looking for fuel consumption (which will dictate C02 output) and work produced, probably measured as cubic foot of air moved per minute.

Moving on.

After looking at a few more gas-powered leaf blowers, it’s clear that they use so little fuel that homeowners don’t care what the fuel consumption is.  The issue of fuel consumption per hour, or typical run time on a tank of gas, is simply not addressed in any of the consumer literature for these devices.

You really have to dig to get it.  Luckily, Stihl introduced some fuel-efficient models about a decade ago, and as part of that, they produced statistics on typical gasoline consumption per hour.  These were aimed at demonstrating cost savings to professional users such as landscape maintenance companies.

With that in hand, it’s just a question of comparing some off-the-shelf plug-in electric models to a couple of efficient Stihl gas models.  Here’s the calculation.

Discussion

The bottom-line figure seems completely credible to me. 

For a Prius, the equivalent number would be 2.5 to 1.  That’s my best estimate (presented in long-ago prior posts), based on our experience with a 2021 Prius Prime.

It’s no surprise that the ratio would be not quite 7 to 1 when comparing small two-stroke engines to electric motors.  In general, engine efficient drops with size, due to proportionately larger heat losses in small engines.  And two-stroke engines are designed for a good power-to-weight ratio, not for fuel efficiency.  Meanwhile, electric motor efficiency — at least at this size — varies only modestly by size.  And as a result, what was a 2.5 to 1 advantage for electric cars becomes a 7 to 1 advantage for electric leaf blowers.

That said, the global warming impact of these devices is almost negligible, at least in terms of C02 emissions.  Note, from the table above, that you’d have to run those leaf blowers for about three hours to use up one gallon of gasoline.  Compare that to the U.S. average of about 650 gallons of gasoline per licensed driver per year, and it’s obvious that leaf blowing really doesn’t much matter, in the overall U.S. carbon budget.

That said, this is just another illustration of something that I hope is becoming increasingly clear to most Americans:  The future is electric.  The rapid de-carbonization of the grid means that more and more frequently, the low-carbon option is going to be the electric option.  Whether that’s for transportation, heating with heat pumps (Post G22-058), or for moving your leaves from place to place.

On the smugness of raking, or, TANSTAAFL

I’m sure that at least some readers have thought to themselves, “Why use a leaf blower at all?  I rake my leaves, therefore I don’t use any fossil fuels to collect my leaves.”. 

Well, it just ain’t that simple. 

  • Raking consumes energy.
  • We supply that energy with fuel.
  • That fuel is a highly refined substance called “food”.
  • Food production and distribution consumes enormous amounts of fossil fuel.

One way or the other, everybody wants to think that there’s a free lunch.  In this case, the free lunch is the illusion that if you don’t consume fossil fuels directly, then you can ignore the fact that you’re consuming them indirectly.

And I’m the guy who gets to tell you that nope, there ain’t no such thing as a free lunch.  The facts are that:

  • it took a lot of fossil fuels to make your lunch, and
  • if more exercise means you eat a bigger lunch, then
  • more exercise means you consume more fossil fuels.

The only trick is that you consume those fossil fuels indirectly, via increased food consumption, not directly, by gassing up your power tools.

I was introduced to this concept in an article entitled “Bicycling Wastes Gas?“.  I can do no better than suggest that you read it.

Here’s the story of how I finally came to understand this.  In my youth, for two years, I biked to work about three times a week, during the warm weather.  Work, in this case, was downtown Washington DC.  The round-trip distance was about 32 miles.  For a guy my size, that burns about 1600 calories.

Lo and behold, I found myself eating a lot more.  Conservation of energy, and all that.  Those 1600 calories of daily exercise had to come from somewhere.  And if my weight remained stable, they had to come from an additional 1600 calories of food.

The kicker is that, for the standard American diet, it takes about 10 fossil-fuel calories to make and deliver one edible calorie.  Estimates vary, but that’s a nice round credible number.  So, while 1600 calories doesn’t sound like much energy (for comparison, a gallon of gas contains about 31,000 (kilo) calories of energy in it), once you factor in how the fossil fuel energy required for one edible calorie, suddenly, you realize that your 1600 calories of typical-American-diet embodies as much fossil fuel as … roughly half-a-gallon of gasoline.

Here’s a reference that, at the end, comes to the same conclusion that I’m about to state.  Bottom line:  As a bicyclist, eating the average American diet, I get about 63 MPG equivalent.  That is, when you divide the additional fossil fuels required, to produce the additional food I consumed, when I biked 32 miles a day, at the standard U.S. diet, by the total miles traveled, that worked out to be 63 MPGe.  (Where the “e” means that it’s compared the total fossil fuel energy to the amount of energy in a gallon of gasoline.)

(You have to be careful when you do such a calculation, because exercise calories-per-hour data are always the gross calories, including your basal metabolism.  Nobody cites the additional calories consumed by the exericise, over and above basal metabolism — the amount you would burn in any case.  You have to derive that before doing the calculation.)

Your mileage will, of course, depend on what you eat.  Potatoes embody very little fossil fuel.  Beef embodies an almost unbelievably large amount.  And many have pointed out that typical ovo-lacto-vegetarian diets embody about half as much fossil fuel as typical carnivorous diets (reference, Pimental, Cornell U.).

But to make this clear, assuming 10 fossil fuel calories per edible calorie, if my wife and I bike together, and maintain a stable weight, we actually consume more fossil fuel than if we drove together in a gas Prius.  And me, by myself, bicycling (while eating the average American diet) consumes more fossil fuel per mile than traveling on electricity in a Prius.

In other words, if I parked my electric Prius and did all my travel by bike — while eating the standard American diet — if my travel miles were held constant, I would increase my fossil fuel consumption.

Weird, huh?  And saying that inevitably makes bicycling advocates angry.  Nevertheless, it’s just math.  And a belief in basic physics, i.e., conservation of energy.

Arguably, the biggest fossil fuel savings from committing to using a bike rather than a car comes from total miles traveled.  Because, in fact, if I have to power them myself, my total miles traveled will not remain constant.  Not even when considering local transport only.  A short jaunt to the hardware store by car becomes a major investment in time and effort by bike.  Consequently, if my only option were biking, I’d be making a lot fewer trips to the hardware store.

What about leaf raking?  With that as preamble, at my weight, this calculator says I’d burn a gross total of 481 calories per hour, raking my lawn, from which I need to net out about 135 an hour for basal metabolism (e.g., just sitting and reading).  For me, then, leaf raking is a net ~350 calories per hour.  Supplying an additional 350 calories, with the average American diet, requires 3500 (kilo) calories of fossil fuel energy.  Or about as much as you’d get in 0.11 gallons of gas.  Inverting that, by raking leaves (and replacing those calories with the average American diet), I consume gasoline-equivalents at the rate of about one gallon every nine hours.

Compare that to the gallon-every-three-hours of the smaller gas-powered leaf blower above.

Conclusion:  Once you factor in the “fuel” for your leaf raking, you consume about one-third as much fossil fuel as you would using a small leaf blower.  That’s per hour.

How that stacks up per cubic yard of leaves is anybody’s guess.  But my guess is that, as with my example of bicycling above, your fossil fuel consumption from food-powered leaf raking is not hugely different from gas-powered leaf blowing.  All due to the fossil fuels embodied in the extra food required to replace the calories burned in raking.

And, as with the bicycling example above, it’s a pretty good bet that electrically-powered leaf collection — your electric leaf blower — beats hand raking, in terms of total fossil fuel impact.

There are plenty of good reasons to rake leaves by hand.  Less noise.  Great exercise.  Commune with nature.

And, as with bike-versus-car, if you are powering the operation with your own muscles, you’re probably going to do a lot less.  You’ll likely to be motivated to move the leaves less, and maybe be motivated to #leavetheleaves.  All of those are positives.

But in terms of the implications of that for fossil fuel use, that’s far from clear.  Raking requires energy.  That comes from food.  If your weight is stable, more energy output requires more food input.  And food production in the U.S. requires large amounts of fossil fuels.  Bottom line is that there ain’t no such thing as a free lunch.

Post G22-062, notes on trying to grow pawpaw from seed

 

Update, July 2023:  Near as I can tell, none of these saved seeds germinated.  So this ended up being a lot of work for nothing.  This fall, I’m going to try something easier, such as tossing whole fruit into pots of soil and seeing what comes up the next year. 

I have a couple of pawpaw trees in my back yard.  Well, two big ones, pictured above.  And then what amounts to a growing pawpaw patch all around them.

Near as I can reconstruct from old emails, these were planted in the spring of 2009, and they are:

  • Stark Brothers Mango Grafted Pawpaw.  This is a large-fruited, late-ripening variety with particularly tasty fruit.  Here’s their ad.
  • Edible Landscaping Select Pawpaw.  This is just a normal, native-to-Virginia pawpaw, that the folks at Edible Landscaping selected for better-than-average fruit.  This is a small-fruited, early-ripening variety. Here’s their ad.

I have, on occasion, eaten some of the Mango Grafted pawpaws, and they are delicious.  I no longer eat pawpaws, though — see Post G24.

Propagating pawpaws

I’ve now been asked to supply some fruit to people who want to try growing pawpaws.

I naively said, sure, I’ll just pick up some of the remains of the rotting fruit that are still on the ground.  I figured, seeds are tough, a seed is a seed.  Just pick them up, let them over-winter, and plant them next year.  Give it some time, and you too can have a delicious Mango Pawpaw.

But, as is my habit, I decided to do a little research.  And the answer is nope.  Everything I just said is incorrect.

First, from the Home Orchard Education Center, I learned one key fact:  Pawpaws do not grow true to seed.  They are like apples in that regard.  Plant a seed from a Granny Smith apple, and you’ll get an apple tree.  But it’s not going to be a Granny Smith.  Same with pawpaws, apparently.

In particular, seeds from that delicious Mango Grafted pawpaw are not going to produce Mango Grafted pawpaws.  The only way I could get more of Mango Grafted pawpaws would be to .. wait for it … graft a cutting from that tree onto some pawpaw rootstock.  Which, I now realize is probably why grafted is part of the name.  (Duh.)

Second, there’s a recommended process for saving the seeds. Apparently the seeds are fairly fragile, and require significant special treatment.  (Which, to be honest, does not quite square with the dozens and dozens of little pawpaw trees I mowed down this year.  Fragile or not, mine seem to be quite happy to sprout after falling on the ground and overwintering there.)

I’ve now started looking into what you’re supposed to do to save pawpaw seeds.  And there’s quite a bit more to it than than just picking them out of some old rotted fruit and chucking them in a paper bag until next year.

By far the most surprising recommendation is that you’re supposed to keep the seeds moist. That’s a new on on me.  Decades of growing stuff, and the advice has always been the opposite:  Keep saved seeds dry.  But for this one, nope, you have to keep it moist.  “If seeds are dried for 3 days at room temperature, the germination percentage can drop to less than 20%.” (From Peterson’s Pawpaws).

That makes any that I gathered from truly well-rotted fruit suspect.  They weren’t exactly dry, as we’ve gotten a fair bit of rain in the past few weeks.  But they aren’t guaranteed to be moist, as would be the case for seeds from intact fruit.

Separately, you have to chill them.  Commonly, they spend the winter in your fridge, inside something that will keep them moist.  I see recommendations of keeping them on damp paper towels, moist sand/peat moss mix, moist sphagnum moss, moist potting mix, or some similar sterile medium.  Inside a zip-lock bag seems to be the most common technique.

But you can also plant them outside, keep their planted area moist, and let the winter chill them for you.

Third, the common recommendation is to remove all traces of pulp and membrane from the seeds.  Apparently, there’s something in the pulp that inhibits growth.

Finally, if you plant in containers, for eventual transplanting into the ground, those containers need to be deep, as these produce a long and fragile taproot.  That much I already knew as these are reputed to be almost impossible to transplant out of the ground.  I’ll be using my paper bag technique from Post G22-012.

References also say that a) the seeds need high (75F to 85F) temperatures to germinate, one source specifies a soil temperature of 70F to 75F, b) they typically take a month to germinate in any case, C) they can do with a 24-hour warm water soak to speed germination, and d) you don’t get much foliage for the first couple of years.  All told, this seems like a project for somebody with more patience than I have.

One source — and only one source — says that wild pawpaw seeds need to be planted in soil taken from around the parent tree.  Something about microbes.  Not sure I believe that one.  That same source — and only that source — says to store them inside in a paper bag for a couple of months, then moisten and refrigerate.

References vary on whether or not you can freeze them.  Some say yes, some say absolutely not.  I am dead sure that these would freeze over the winter, naturally, so I find it hard to believe that freezing them would kill them.

Finally, the “float test” to separate viable and non-viable seeds does not appear to work on pawpaws (reference).  Which, to me, goes hand-in-hand with having to keep them moist.  This is just not a normal seed.

In any case, here are a few internet references on what you are supposed to do.

The plan

At this point, given that I want to try this, my plan is to prep a large number of seeds for overwintering in the fridge, and give away bags of prepped seeds.  If I do this again next year, I’ll know enough to collect the whole fruit before they rot, to ensure that the seeds do not dry out.

So, the plan is:

  • Start with whole fruit where possible.
  • Scrub the pulp and membrane off the seeds
  • Give the seeds the recommended soak in dilute bleach solution.
  • Bag them up in ziplock bags of moist potting soil.

Then they go into the fridge until next spring.

Edit:  Addendum

These are now done and stored away in the fridge.  All told, it took me maybe an hour and a half to process about 100 pawpaw seeds for storage over the winter.

I took the advice of several internet sites and “scrubbed” the seeds and pulp against a piece of hardware cloth, set over a bucket.  This was the most time-consuming step, mostly because I didn’t quite grasp just how hard you had to scrub, to part the seed from the surrounding membrane.  It went a lot faster once I decided to put more effort into it.  And it was obvious when I had managed to get a seed out of its membrane jacket.

I soaked the mostly-clean seeds a few minutes, then cleaned off any remaining pulp one-by-one.

Five minutes in a weak bleach solution (10-to-1 dilution of standard laundry bleach), several rinses to remove the bleach, and the seeds got tossed into Ziplock bags filled with damp potting soil.  And the bags got tossed into the back of the fridge.

The next challenge will be planting them in the spring.  As I understand it, pawpaw seedlings really don’t like to be transplanted.  They grow a long, fragile tap root before they even begin to break the surface of the soil.

Direct-sowing into the soil is preferred.   But I’m planning to raise seedlings to give away in next spring.  So I need to find or make some suitable containers.

You can find any number of very tall plant pots and containers specifically designed for growing tree seedlings.  But it is far harder to find very tall biodegradable pots, so that you can plant the seedling without disturbing the plant roots.  In particular, rumor has it that pawpaws can put out a one-foot tap root before you even see any leaves.  So I was looking for slender biodegradable pots at least one foot tall.

The best of the bunch seemed to be the lightweight Zipset (r) plant bands, 14″ x 3″ (reference).  These are more-or-less open-ended un-waxed lightweight milk cartons, and should degrade in less than a year.   They seemed to have the exact right combination of size, stiffness, and biodegradability.  They are cheap if bought in bulk, but the smallest quantity I could buy was a carton of 500.  That was far too many.

Instead, I’m going with 17″ tall biodegradable fabric grow bags (reference).  I can pick up 50 for $15.  The big unknown there is whether or not they really will degrade once planted.  I’ll bury a few this winter and dig them up before I decide whether or not to start my pawpaw seedlings in them.

In any case, at that price, the cost of the potting soil to fill them will far exceed the cost of the grow bags.  So it’s not like the bags represent a big money gamble in the overall scheme of things.  .

I decided against several varieties of home-made pots, just because I didn’t think they would be sturdy enough.  I could, in theory, make a foot-tall paper pot, out of newspaper.  Or use grocery bags, cut up and re-glued.  Maybe wrapped with jute netting, for strength. And so on and so on.

But all of those seemed to be a risk, and none of them seemed to be worth the trouble when I appear to be able to buy usable containers for 30 cents apiece.  After going to all this trouble, it didn’t seem very bright to take a gamble on the containers used to grow the seedlings.

So, tall grow bags it is.  We’ll see how this all turns out, next spring.

G22-061: Okrapocalypse, or, how does your garden slow?

Okrapocalypse

For the past month or two, when I looked out my bedroom window in the morning, I could see a half-dozen okra blossoms.  Every morning.  They are quite striking, for a vegetable flower.  They only last a day.  And for the past couple of months, my row of okra set a handful of new blossoms and seed pods daily, just like clockwork.

A few days ago, the clock stopped.  The weather finally turned a bit cooler, and I haven’t seen an okra blossom since.  Zero.  Production of new okra didn’t slow down.  It ceased overnight.

Source:  Weather underground.

Of course I knew that okra was a warm-season plant.  Everybody says that.  And the plants themselves are fine.  Just no new flowers or pods.  Our first frost date is probably at least a month away.  So maybe if we get another warm spell, that will pick right back up.

The surprise to me was how knife-edged the pod production is, as a function of temperature.  One day my okra patch was chugging right along.  The next day, everything having to do with flowers, seeds, and pods had ground to a halt.  All due to a roughly 10F drop in the average temperature.

By contrast, tomatoes and peppers are also warm-weather plants.  But they’re still putting out flowers and ripening fruit.  Albeit quite slowly, now that things are cooler.

And, of course, I’ve taken advantage of the cooler weather with a fall sowing of lettuce, spinach, and some beets.

So it’s not a total loss.  Greens are food.  Sort of.

But we do like okra in this household.  It shall be missed.

Is this mother nature’s way of telling me to get a greenhouse?

At this point, I was going to go off on a tangent about degree days, and how those can be calculated specific to individual crops.  And other such technical stuff.

But, in fact, one can just sidestep a lot of degree-day issues by growing in a greenhouse.  Why be at the mercy of the weather when you can make your own?

In fact, when you get right down to it, this early end of okra production is just another example of what I observed last spring:  It’s not very smart to provide frost protection alone, for plants (Post G22-009).  Even if plants will grow in cold spring weather, they sure don’t grow very fast.  By providing frost protection only, you go to a lot of effort to keep plants alive.  But you get very little in the way of net production, because growth is so slow.

As exemplified by the 100+ days it took my 49-day early season tomatoes to begin producing.

Not that I regret that — those early-season tomatoes produced as advertised (before the 4th of July).  They are still producing.  But I bet they would have produced earlier still if I’d had them in a greenhouse.  (N.B., tomatoes have perfect flowers (both male and female parts in the same flower), and can be pollinated just by flicking the flowers or buzzing them with an electric toothbrush.  So no bees needed.)

I have resisted getting a greenhouse, for many reasons.  Durable ones are expensive, cheap ones are just so much eventual landfill fodder.  They require that you install irrigation.  They require maintenance.  And with common plastic greenhouses, you still need frost protection, as the greenhouse itself will typically do little to warm the plants at night.

Plus, they seem like cheating, for the home gardener.  What’s the point of marking the passage of the year if you’re monkeying around with the seasons by installing a greenhouse?

That said, I already have irrigation set up (Post G22-037).  Plus, I have a roll of clear plastic that looks like a more-than-lifetime supply at this point.

And I sure wouldn’t mind getting a little more okra this year.

Not to mention the pests.  A greenhouse might keep the @#$@# deer out, so I could grow without setting up my backyard like an armed camp.

All things considered, I feel myself sliding down that slippery slope, from growing in open beds, to being the kind of backyard gardener who puts in a greenhouse.

I never thought it would end up like this.

(‿|‿)

But.

But what fraction of the slow spring and fall growth is due to temperature, and what fraction is due to reduced sunlight?   Farmers around here grow their spring crops in poly tunnels, so I know it works.  But I’d still like to know that split before proceeding.

Turns out, it’s fairly easy to get information on typical total solar energy by month.  This is from the National Renewable Energy Labs PVWatts calculator:

Doing the math, you can see that over the course of the growing season, lack of sunlight is a trivial factor at the start of the growing season, but a reasonably important one by the end of the growing season.  In October, my garden would get 30 percent less solar energy than it does at the peak of the summer.

Fair enough, that all makes sense.  Lack of sunlight isn’t an issue for early spring crops.  But for fall crops, a greenhouse might have more utility in letting existing crops fruit longer, rather than for growing new crops late in the year.

As I ponder my healthy-but-podless okra plants, I believe I’d settle for that.

Post G22-060, two gardening fails

 

Here are a couple of cases of “if it seems too good to be true, it probably is.”

Does a weak citric acid solution kill powdery mildew?

No.

See Post G22-039 for background.  This is based on a product offered on Amazon that said it would kill powdery mildew on plants.  That product was merely a very dilute solution of citric acid in water.  I was originally going to do a formal test, with a “control” patch, but the powdery mildew didn’t show up on time.

Instead, here it is firmly established on what’s left of my summer squash.  Near as I can tell, a dilute citric acid solution had no impact on well-established powdery mildew.  Here are two pictures, one before spraying citric acid, and one about a week after.  Any apparent difference is just an artifact of the lighting, compounded by the complete loss of some of the leaves.

Do bamboo leaves make a good weed killer?

No.  Or, at least, not good enough.  Or maybe it’s just very slow at it.  All of which is a pity, as bamboo surely kills lots of useful plants.

See Post G22-052 for background.  Bamboo is one of many allelopathic plants, that is, plants that produce poisons to keep competing plants in check.  I figured, why not give it a shot as weed killer.

Before:

Roughly seven weeks later, I pulled back half of the now-brown bamboo.  Unfortunately, there’s still plenty of live weeds growing through the driveway, like so:

 

 

Post G22-059, first summary of this year’s gardening season.

 

I tried a number of new plants and techniques in this year’s vegetable garden.  As we move into September, it’s time to start sorting out what worked and what didn’t.

Drip irrigation (Post G22-026, Post G22-027, Post G22-037).  A huge success.  For a bit over $100 in parts, and maybe two hours of labor, I can now water my entire garden either by hooking up to my rain barrels, or by using water from the spigot.  I can reconfigure it and add to it at will.  Key takeaway:  Use 1/2″ drip line.

Portable electric fence as a deer deterrent (Post G22-018).  A winner.  This is another project that took almost no time and a bit over $100 to set up.  Push in some cheap plastic posts, run the “wire” (more like metallized twine) through them, pound in a grounding rod, and hook up a small fence charger.  With deer deterrents, it’s hard to tell whether they worked or you just got lucky.  But I’ve had essentially zero deer damage since this went up.  I suspect the deer really don’t much like it.  (And, having tested it on myself, I concur.)  Key takeaway:  The technology has changed to make these easy, cheap, and flexible.  If you only need a small fence, you only need a small, cheap fence charger.

Sprawl technique for tomatoes (Post G22-035).  Thumbs down.  This year, I tried letting one bed of tomatoes grow un-staked and un-caged.  Just let them sprawl.  It’s by far the easiest way to grow them, but I’m not going to do that again.  They grow just fine.  I didn’t see (e.g.) any higher levels of leaf diseases and such.  This bed is now a mat of interwoven vines.  It’s hard to see the ripe tomatoes, and I’m losing more tomatoes to garden pests than I would if I had staked them.  Key takeaway:  The problem isn’t growing them, it’s getting a good harvest after allowing the vines to sprawl in the garden bed.

Cold-tolerant (early season) tomatoes (Post G22-025, Ripe Tomatoes in June).  A big winner.  This worked out quite well.  Not only did I have tomatoes by the end of June, those plants are still producing a decent yield of salad-sized tomatoes.  They slowed down in the heat of the summer, but it looks like they’re picking up steam as the cooler weather sets in.  I also learned a lot about what “days to maturity” really means.  Key takeaway:  Pick the right varieties, and you can have tomatoes in June without having a hothouse.

Growing large seedlings in paper lunch bags (Post G22-012, Post G22-017).  Works well.  This year, my butternut squash and pumpkin seedlings outgrew the paper cups I started them in before I was ready to transplant them to the garden. I moved them to doubled-up paper lunch bags filled with potting mix.  The idea was to give them room to grow and to avoid transplant shock by planting them bag and all.  Coincidence or not, I’m having my best butternut squash year ever.  Key takeway:  Double up the bags, and handle them gently when it’s time to plant.

More to come.

Post G22-055, Crock Pot crackpot.

 

Of squash and men.

As of this writing, I have the delightful problem of having almost too much summer squash.  Accordingly, this morning’s chore was to put together a squash-and-tomato casserole in the Crock Pot®.  Where it is simmering away right now.

Which got me thinking about my lifelong Crock Pot journey.  And all the very-nearly-useless things I’ve figured out about Crock Pots along the way.  Which I shall now pass along. Continue reading Post G22-055, Crock Pot crackpot.

Post G22-050: Parthenocarpic squash, is this a joke?

 

Edited 8/6/2022:  I may have been somewhat hasty in my original post.  I removed the insect barrier.  As expected, I am now getting full-sized summer squash.  But the largest of these, so far, has only a vestige of seeds.  For all intents and purposes, it’s seedless.  To me, this suggests that, at some point, these squash plants did indeed begin producing full-sized fruit despite a lack of pollination.  Perhaps they have to produce a handful of tiny ones first, before they give up on getting pollinated and begin producing full-sized parthenocarpic fruit.

The original post follows.

One tiny detail.  The seed packets for parthenocarpic squash failed to mention one tiny, little detail.

Looking on the bright side, you know how summer squash will go from small to gigantic before you know it?  One day they’re barely edible, three days later they’re barely liftable?

Or how you can be inundated with zucchini, to the point where you have to keep dreaming up new ways to cook it?  Where you start figuring out ways to hide it in food, so that your family won’t object.

The good news is, parthenocarpic squash have both of those problems licked.

They’re tiny. Unless a miracle happens, my parthenocarpic summer squash are going to weigh in somewhere around one ounce each.

If you’re interested, read on.  Or just check the photos below. Continue reading Post G22-050: Parthenocarpic squash, is this a joke?