That’s the traditional day for planting potatoes, in this climate.
But my new raised beds aren’t ready yet. And the old ones are a weedy mess. Which I didn’t much feel like hoeing out of the way, this rainy St. Patrick’s day morning.
So I planted this year’s potatoes as no-dig (no-till) potatoes. I placed them on top of an existing weedy garden bed, and buried them under half-a-foot of free leaf mulch.
At the start of the pandemic, I recycled some political yard signs and bamboo into a set of raised garden beds (Post G05). After three years of intensive use, a) those are now in disrepair, and b) I know a whole lot more about gardening.
My plan is to replace those beds with something better. With St. Patrick’s day just one week away — the traditional day for planting potatoes — I can’t procrastinate much longer. Time to finish pondering and start shoveling.
This post documents the final design. The next post will show the construction.
This post is about making sure my new garden beds don’t end up in the shadow of my back porch, during the summer. Based on the length of the shadows today, in late winter. And, ultimately, based simply on the height of the porch roof.
To cut to the chase: If you use Excel, and the NOAA sun-angle calculator, you can accurately predict the length of a shadow, for any date and time, anywhere on earth, via this formula:
This is the first of two posts on finding the sunniest spot in a yard that has shade trees on either side. This one uses geometry. The next one will use time-lapse photography on a sunny day.
With any luck, both approaches will tell me the same thing.
If your yard is bordered by shade trees, locate the beds so that due south (180 degrees) splits the compass bearing from your bed to each line of trees. This gives a surprising-looking result for my back yard. It’s not at all what you’d naively think, just looking at the trees and the yard.
Garden bed location 1: Wrong.
I started gardening seriously during the pandemic. Temporary raised beds were made from recycled campaign yard signs and bamboo. I placed those in seemingly-reasonable locations in my back yard. In part, they were filling in low spots on the lawn. But it seemed like they were located so as to get the best sun.
I’m now getting around to putting in something more permanent. This time, I’m not going to wing it, but instead want to know what spot in my back yard gets the most sunlight.
It’s not obvious. I have tall trees on either edge of my yard. And, interestingly enough, what appears to be the obvious solution — locate the garden beds in the middle of the yard, away from both tree lines — isn’t even close to being right.
So, eyeball a couple of birds’-eye views of my back yard, and see if you think I put the beds in roughly the right place:
Looks pretty good, doesn’t it? You might even say that the location doesn’t much matter, because you’re going to get the same number of hours of sunlight almost anywhere in that back yard, regardless. What’s shaded in the morning will be sunny in the afternoon, and vice-versa.
Problem is, an hour of sun is not an hour of sun. Sunlight is much stronger around solar noon, and is weaker the farther you are from noon. And, because the sun is due south at noon (in the Northern hemisphere), you have to know which direction is south, in order to judge what part of the yard gets the most solar energy.
You need to figure out the locations in your yard that place due south directly between those lines of trees. Those locations get the greatest amount of high-intensity, near-noon sunlight.
To cut to the chase, you need to calculate where your potential garden site is, relative to the obstructing trees, and to due south. The sunniest locations in the yard will have these two properties.
Due south (180 degrees) bisects the angle from your location to each side of obstructing trees. E.g., find a spot where the bearing to one set of trees is 150 degrees (180 – 30), and the bearing to the other set of trees is 210 degrees (180 + 30). That is, you get equal hours of morning and afternoon sun.
The angle from your location, to the obstructing trees, is as wide as possible. For example, the location with a 60 degree spread above will get more total sunlight than a location with a 40 degree spread. That is, you get as many total hours of sun as possible.
So now, take a look at my back yard, oriented so that south is directly down. Do you want to change your prior answer? By the look of the shadows, this is about 11 AM solar time. Note that the left edge of the yard is already in sunlight.
Skirting a couple of pitfalls.
Let me take a brief break to mention a couple of pitfalls that can mess up your attempts to locate your garden in the sunniest spot on the yard.
Daylight savings time. Man I hate having to get up at 2 AM to turn all the clocks forward, as required by law. But the upshot is that solar noon occurs around 1 PM during daylight savings time. For example, on the hourly insolation graph above, peak insolation occurs around 13:00, or 1 PM. That’s not a mistake, that’s just daylight savings time. So if it’s summer, and you look to see where the shadows fall at noon, you’re screwing up. Because noon, daylight savings time, is actually 11 AM solar time.
Above: Compass set up for 10 degrees west magnetic declination
Magnetic declination. Declination is the extent to which magnetic north — where the compass needle points — deviates from true north. Because of magnetic declination, you can’t simply use the raw readings from a standard magnetic compass in order to locate your garden in the right spot.
If you have a compass made for use on land, and it’s anything but the most basic compass, chances are you can adjust the compass to account for declination.
You can find the magnetic declination for your locality at the US Geological Survey, among other places. Currently, magnetic declination at Vienna VA is about 10 degrees west. That means that the compass needle actually points to a heading of about 350 degrees, not 360 degrees (true north). That’s about 2.5 degrees further west than when I was a kid in the 1970s.
Magnetic declination is one of those incredibly simple topics that always manages to get an incredibly opaque explanation. But as long as you have a compass that can be set to account for your local declination, it’s really simple. The picture above shows a compass set up for 10 degrees west declination. Despite the fuzziness of the photo, I think it’s obvious that the compass body has been offset 10 degrees relative to the degree ring. When the needle points to 350 degrees (10 degrees west of true north), 360 or 0 on the degree ring shows you true north.
The sunniest spots in my back yard are directly next to the trees.
I can now take Google Earth, and start drawing in the angles between various backyard locations, and the ends of the lines of shading trees at the sides of the yard. It’s a little crude, but the conclusion is inescapable. I put the temporary beds too close to the middle of the yard. For the most solar energy possible, they ought to be almost under the trees at the side of the yard. Like so:
Which, to be honest, I would not have guessed, just eyeballing it.
Over the coming weekend, I’ll set up a stop-motion camera to film my back yard for one sunny day. With that, I should be able to validate that the area that gets the most solar energy is the one outlined. And I should be able to determine just how much energy I lose if I move away from that optimum spot.
People say the ancients constructed their calendars to keep track of religious holidays, based on astronomical events. Possibly true. But a nice side benefit of their religion is that it gave them a clear idea of when to plant their crops in the spring.
In the modern world, of course, we eschew such religion-based planting rituals. Thus my potatoes will go in the ground on St. Patrick’s day, and no sooner. Because that’s Science.
If left to my own devices, I would undoubtedly plant too early. Hence the need for my quasi-religious planting ritual. Here in Vienna VA, today’s high is expected to be near 80. Which definitely gets me in a gardening frame of mind. But tomorrow’s low is well below freezing. We’re still six weeks from our likely last-frost date.
Without getting into whys and wherefores of our ever-wackier weather, this post presents my vegetable garden plan for the year. It takes the form of three questions:
Why?
What?
How?
A brief recap
I started my current round of gardening in order to have something to do during the pit of the COVID-19 pandemic. If nothing else, shoveling around a few tons of dirt to create raised beds provided much-needed exercise (Post G05).
Many people did the same, leading to shortages of everything gardening-related in 2020. Starting with empty seed racks at my local hardware stores (Post #G02, April 21, 2020) and ending with a long-lasting shortage of canning jar lids (Post #G21, August 2020).
Gardening was a much nicer experience then than now. The cessation of much local and long-distance travel meant that the air was cleaner, the skies were blue-er (Post #614, Post #618) , and neighborhoods were a lot quieter. So quiet I could hear the hum of the bees at work in the garden (Post #G11), a sound I have not heard since. A big bed of sunflowers, just outside my bedroom window, provided much-needed cheer during what was otherwise a fairly dark time.
But now, the air once again stinks of diesel exhaust, the Northern Virginia summer sky has returned to its traditional smog-white, the constant noise of traffic and construction smothers sound of the bees, and gyms are open for business.
In other words, things are back to normal.
1: Why? It’s now my hobby.
When I distill it down, I’m going to continue to garden for four reasons.
One, it gives me a physical activity that actually has a purpose. Sure, I can go to the gym, and get exercise for exercise’s sake. I can walk around the neighborhood, for the sake of walking around the neighborhood. Gardening is a way to get non-pointless exercise.
Two, I really like growing plants. I guess I can come out and say that. Mostly food. But flowers are OK, in moderation.
Third, I’m cheap. As hobbies go, annual costs don’t get much cheaper than a few pounds of potatoes and a few packets of seeds. I’m not convinced that my gardening pays for itself in the value of produce. But the fact that I get anything at all useful out of a hobby is a bonus in and of itself.
Finally, it leaves nothing permanent. What isn’t eaten turns to compost. So, unlike (say) woodworking, this doesn’t produce yet-more-clutter, during a period of my life when I’m doing my best to get rid of stuff
2: What? Only stuff we like to eat.
In an intellectual breakthrough this year, I’ve decided on the following guidelines:
Only plant stuff that we actually like to eat.
Don’t plant stuff that the deer like to eat
Don’t plant stuff that the bugs like to eat.
Don’t plant stuff susceptible to diseases common in my garden.
Being the kind of guy I am, I of course formalized that with a spreadsheet. But it doesn’t tell me anything I didn’t already know.
Yellow: Certain herbs and herb-like plants rank highly here because they are extremely easy to grow, take up little room and cost an arm and a leg at the store. So, dill and rosemary, which I already grow, and ginger and turmeric, which are apparently easy to grow from grocery-store-purchased product.
Light blue: Potatoes, sweet potatoes, and winter squash. These all provide a lot of calories per square foot and (so far) have been both extremely easy to grow and highly productive in my garden. Plus, we like to eat them.
Red: Tomatoes and sweet peppers. Easy to grow, we like to eat them. Say no more.
Dark blue: The entire garlic and onion clan. I’ve had such spotty luck with these over the years, I’m going to skip them this year. Plus, my yields have been lousy.
Green: Peas, beans, lettuce, okra. We like to eat them just fine, but all require significant fuss. And, except for green beans, in a good year, yields are modest at best. But peas and lettuce can go in when it’s cold, and my wife likes green beans. So these are definitely going to get planted. Some. Not a lot.
Purple: Cucumbers and summer squash. I’ve had such a bad time with insect pests that I’m skipping those this year.
3: How? When you come to a fork in the road, take it.
After three years in the Virginia climate, my temporary raised beds are “showing their age”. Which is a nice way of saying “falling apart”. I put up a set of temporary raised beds during the pandemic, recycling some yard signs, bamboo, and other materials around the yard. Their temporary nature is now showing pretty badly.
I did that to minimize my investment. I figured that if gardening didn’t work out, I could just tear them apart, spread the dirt on the low spots on the lawn, and plant grass. Nothing wasted. Nothing headed for the landfill that wasn’t already headed there before I tried gardening.
So I’ve reached a fork in the road. Either I do what I had planned on originally, take the beds down, use the dirt to even out the lawn, and be done with gardening. Or kick it up a notch.
Separately, things snowballed beyond the mere construction of the beds. In addition to the beds, I now have irrigation line, various types of row cover and insect netting, trellising material, tomato cages, deer deterrent devices, and so on. Not a huge dollar investment, as these things go. But it’s a lot of stuff that serves no purpose outside of gardening.
The upshot is that I’m now going to go back and do this right. But only as a last resort. The patchwork of temporary beds of varying depths, oriented along the low spots of the lawn, will be replaced by a single long bed oriented east-west, with a permanent trellis along the back. This will simplify everything from irrigation to protection against deer, and dovetail with the remaining in-ground beds that are now devoted to cane fruits.
I quite like the coroplast (yard sign) sides, and as I have several long sheets of that around, the new bed is going to be coroplast-and-post as well. I see no reason to import materials if I have durable materials on hand that would otherwise be trash.
As an extra added bonus, this allows me to re-shovel the multiple tons of dirt that I ordered in the first place. Much better than wasting my time at the gym. And see how my hugelculture experiment turned out. There are trash pieces of wood at the bottoms of all these beds, and I’ll get to see what happened to them after three years in the soil.
The goal is to have a single, well-constructed bed of uniform depth, with trellising, deer protection, and irrigation built in. We’ll see how close I come to that ideal.
Conclusion
After three years of seat-of-the-pants gardening in temporary raised beds, I have reached a fork in the road. I’m going to take what I learned in the past three years, and move forward with a single permanent bed incorporating everything I think I need to grow a bit of vegetables and flowers in my back yard. And at that point, I’ll focus on a few things that we really like to eat fresh out of the garden and that seem to grow well in this climate. And hope for the best.
As my store-bought organic potatoes chit (sprout), in anticipation of planting on St. Patrick’s day, I am in the process of figuring out what else I’m going to grow this year.
In a surprise move, I’m going to take my wife’s advice and … wait for it — only plant stuff that we actually like to eat.
Then it occurred to me that I should only plant stuff that the deer don’t like to eat.
Now that I was surfing that intellectual tsunami, I went out on a limb by saying that I probably don’t want to plant stuff that my local bugs like to eat.
Finally, drafting in the wake of that runaway 18-wheeler of brilliance, maybe I should avoid plants that are susceptible to diseases frequently found in my garden.
Fantastic. Easy-peasy. Planning accomplished.
I just need to fill in the details.
Unfortunately, when I do the Venn diagram of those four insights, I’m left with:
And I’m not all that sure about the red one.
(Plus, as I understand it, that “guy” on the left is now part of a lefty-liberal plot for the emasculation of America. Pink ears, blue shoes — that’s certainly a mixed message, but that’s the way the libs go after it. Slow rot. Next thing you know, they’ll be taking away his angry eyes. And then they’re coming for your potato cannon and spud gun!! You’ve been warned!!!)
I can tell from the daffodils and crocuses coming up in the yard.
The seed catalogs piling up in the mail box.
And a note on my wife’s calendar saying simply, “chit”.
Edit: Spring 2025: Does chitting work, to get you a head start on the season? Yes. See Post G24-012 for a little controlled trial of chitting-versus-not-chitting. Same potatoes, same plot of ground, planted on the same day. The chitted potatoes were so far ahead of the un-chitted ones that it ended up being not a fair test of the impact of chitting on yields, as the late-starting non-chitted potatoes essentially grew up in the shadow of the chitted ones.
One of the joys of gardening is coming across fresh-frozen produce, in the dead of winter, that you squirreled away last summer.
In the Spring of 2022, after determining that freezing was the most energy-efficient way to preserve tomatoes (as long as you have room in an already-running freezer), I froze a bag of early-season “4th of July” tomatoes. Washed them, cut their tops off, put them in a vacuum-sealed bag, and froze them. (Then sealed the bag, after they had frozen.)
The clincher for me was finding out that frozen tomatoes will slip right out of their skins. If you’ve every tried to peel a lot of tomatoes, you know what a plus that is.
That’s what I’m doing, in the video above, with the thawed tomatoes. They already have their tops cut off, they’ve been thawed, and they do, indeed, slip right out of their skins.
I learned that trick from the blog “from the family with love“. (You can see her video of peeling frozen tomatoes at this youtube URL). But, you know, sometimes, there is room for doubt until you actually do it with your own hands.
As a bonus, freezing them (after removing the tops) separates out most of the liquid. When I pulled the now-thawed tomatoes out of their vacuum-seal bag, roughly half of the output was tomato solids, half was tomato water.
Obviously, after freezing the texture isn’t good enough for eating out-of-hand. But for a quick batch of tomato sauce, or for adding some chopped tomatoes to a stew, these are fine. I’m making sauce, so I ran a stick blender through it to pulverize the seeds before reducing it down.
I might even go so far as to say that these are nice. Compared to canned tomatoes, freezing seems to preserve more of that “fresh tomato” taste. I’m vaguely guessing it preserves more of the aromatics that are lost in canning.
So there you have it. Wash them, cut the tops off, freeze, then seal the bag their are in. Thawed half a year later, they are a little taste of summer to enjoy in the dark of winter.
But few people have one. And that’s a situation I’m trying to change.
A couple of months ago, I put away some seeds from the pawpaw trees in my yard, with the idea of starting and giving away pawpaw seedlings in the spring. Preserving viable seeds turned out to be quite a process (Post #G22-062). After a thorough cleaning, the seeds need to be kept moist, and kept cold over the winter. So a couple of plastic bags of seeds-in-damp-potting-soil have been living at the back of my fridge for the past two months.
Today it was time for a mid-season checkup.
They’re still brown (no evidence of mildew or fungus). And they’re still damp, though it’s clear that they have dried out somewhat, so I’m going to top them off with a bit of fresh water. (In hindsight, I should have weighed them before I tucked them into the fridge.)
But, in general, things are proceeding according to plan.
Except that I don’t actually have a plan. I started this in response to a request for pawpaw seeds. I noted how difficult it seemed to be to come by pawpaw seedlings locally. And pawpaws are the only known host of the zebra swallowtail butterfly.
So when you get right down to it, my entire rationale for doing this is butterflies (aw!).
And thus I have fallen into the classic charismatic megafauna trap.As humans, we focus on saving animals that are attractive (pandas). Or noble-looking (elephants). Or have cultural context (bald eagles). Or, in this case, cute, and the Virginia state insect (zebra swallowtail butterfly).
The dead of winter is the perfect time to step back and take a more objective look at this effort. Given that we’re in the middle of the great insect apocalypse, and given that growing trees in suburban yards is more-or-less a zero-sum game (if not a pawpaw, then some other tree), what is it, exactly, that I’m hoping to accomplish.
Is propagating pawpaws the smart thing to do? Aside from the technical gardening challenge of doing this, and helping one insect (because it’s so cute!), is this really the best use of my time?
A summary of expert advice for an insect-friendly urban environment.
As my first attempt at being somewhat more systematic, let me use Google to find seemingly-serious websites offering advice on how to create an insect-friendly urban environment.
To frame that properly, I need to state clearly that urbanized areas constitute only a tiny fraction of U.S. land area. So, from the outset, this list is going to be oriented toward personal actions that residents of urbanized areas may take. My little survey clearly is not going to have the right “weighting” in terms of global impact, because those urbanized areas constitute such a small part of the entire U.S. insect habitat.
You can look at that any number of ways, and arrive at the same conclusion. The U.S. Census has a formal definition of what it considers to be an urbanized area:
Bloomberg has a nicely detailed summary of U.S. land use. You reach much the same conclusion from that as you do from the map above. Urban areas account for a few percent of the total land area of the U.S.
Source: Bloomberg, Here’s How America Uses Its Land,By Dave Merrill and Lauren Leatherby,
So, almost beyond a doubt, policies or actions applicable to the other land categories will have a much larger impact than what gets done in urbanized areas. Pasture/range, forest, cropland, and parks (and other special-use lands) vastly outweigh urban areas in terms of insect habitat.
The easiest way to quantify that is to focus on the diagram above. Roughly speaking, there’s one acre of crop land and two acres of pasture/grazing land for every resident of the U.S. Most of the production from that land is consumed domestically. Adults consume more than kids. If I had to guess, I’d guess that growing a year’s food for two U.S. adults takes up at least six acres of land. Compare that to my suburban lot, and, arguably, what I choose to eat is going to matter a lot more than how I landscape my yard.
But you do what you can.
For urbanites.
That said, below I have tabulated the advice most commonly offered to Joe and Jane Urbanite, to help protect and preserve the insect population. This is literally the first nine reputable sources that showed up in a simple Google query of best things to do to help insects. The full tables may be a bit tough to read, so scroll down for just the good parts.
Just the useful bit:
When I start from this perspective, I’m pretty sure that displacing other species of backyard trees, in favor of pawpaws necessary for a single butterfly species, is probably not the most effective thing I can be doing to help beneficial insects survive in my yard.
#1: Overwhelmingly, the first piece of advice is to reduce the area of your lawn, in favor of … well, just about anything else. Eight of nine sources said some version of that. Minimally, don’t mow it. Maximally, return it to more-or-less a wild area. Maybe plant it with wildflowers. Maybe plant it with insect-friendly plants.
I think I’m going to take this one to heart next year, as I have a large section of my back yard currently covered in black plastic, trying to kill the weeds. And a whole lot of saved flower seeds. I think that’s all going to become a flower bed next year.
#2: Skip the pesticides and herbicides. I think I have that one knocked. The more I grow in my vegetable garden, the less inclined I am toward any type of insecticides. Herbicide? I spell that h-o-e.
#3: Address your outdoor lighting. I had no idea this was quite so much of an issue. Everyone gives the same advice. Minimize outdoor lighting. And if you use outdoor lighting, go toward the red/yellow/amber spectrum, not white. Apparently, there is some truth to the idea that old-fashioned yellow bug lights attract fewer bugs. What also appears true, however, is that the switch to LED street lights. however good that is from the standpoint of reducing energy consumption, is a step backward in terms of harm to the insect population. Apparently, those old fashioned yellow high-pressure sodium lights were reasonably benign, compared to the white light issued by LED or mercury vapor/halide lamps.
For me, this is fixable. I have exactly two small outdoor lights. Both have white bulbs in them. I’ll swap those for bug lights, and problem solved.
#4: Create bee nests, bug hotels, and other protected habitats. Or, alternatively, just leave the edges of your yard looking like crap all the time. That works for me. I now have a great excuse for leaves, branches, pine cones, etc. along the margins of my yard. It’s not sloth, it’s environmentally sound policy. Plausibly the wilder it looks, the more insect-friendly it is.
But you can also buy bits of made habitat. I bought one of those solitary-bee or mason-bee nesting boxes in Spring 2016. Never touched it. Here’s how it looks this morning:
To me, that looks like an underwhelming amount of new-bee production for six years. A lot of the tubes remain untouched. Maybe a half-dozen have clearly released a live bee, as evidenced by the hole in the end of the mud. A few more might hold bees that will emerge this spring. That said, those bees will re-use those tubes, so it’s not clear exactly how many bees this investment produced. Or, for that matter, whether those bees would simply have laid their eggs elsewhere, absent this cute little device.
That said, I already own a couple, so I guess I’ll get the refill tubes, clean them up, and re-hang them. What could it hurt?
I’m going to stop there, except to note that planting native plants (such as pawpaws) is pretty far down the list. And so, as I had begun to suspect, it’s likely that going to all this effort to produce pawpaw seedlings is not very efficient. Laboriously saving the seeds, to produce the seedlings, so that others may displace some trees in their yard with pawpaws, so that the zebra swallowtail has a place to lay eggs … that’s a positive thing to do, but it should hardly be first on the list.
Best guess, after fixing my outdoor lighting, the single smartest thing I can do is transform large portions of the edges of my yard to wildflowers. Around here, it takes considerable effort to keep “wild” patches of yard from being overgrown with less desirable plants. So it’ll take some doing to get a setup that has any hope of maintaining itself, even if I mow it once a year to keep the trees down.
After that, it’s probably a question of being pickier about what I eat. I’m not sure about the extent to which eating organic produce actually avoids use of pesticides, rather than merely substitutes some classes of pesticides for others. But I am pretty sure that foods vary widely in terms of the average amount of pesticide and herbicide used per edible calorie. I think my next step is to see if research can generate any reliable information on that.
Today is St. Patrick’s day.
