Here it is, the final phase of the tomato pot size experiment: side by side and in the ground. It’s a little hard to compare, so far apart and in this weird semi-overcast sunlight. The deep pot toms across the way went in late yesterday, and the plug sheet seedlings, up close, were transplanted 10 days ago. It’s a bit of an odd match-up for an experiment, but this was all an afterthought. The plugs have a big headstart in getting fully rooted, while the potted toms are starting in pretty much twice as big, with a lot more root mass. And they’re off…!
Farm lab (research!)
Pot experiment update #1
The story so far: Five days ago, 10 tomato seedlings, five each of two varieties, were potted up from the plugsheet where they started, to individual deep pots. The pots measure twice as deep as the cells, though they look taller in the photo. Pretty soon, all the toms will be transplanted at the same time, side by side, to see if deeper rooting leads to bigger, better, faster tomato plants. The ones in pots were also buried up to their seed leaves (that first pair that look like wings)—with their power of adventitious rooting, new roots will develop along the buried stem, so there’ll be a LOT more roots. The leafy parts look about the same between the two, while the real action right now is happening underground. In the plugsheet, roots are already circling around the cell walls. In the pots, it’s a root jailbreak, although they’ll find their new walls pretty quick. But walls that won’t be there forever!
Pot experiment
Which pot is better for tomato seedlings, the narrower, deeper, or the shorter, wider one? This is an experiment I’ve started probably half a dozen times over the years, then got so caught up in everything else going on in a typical growing season, I never followed up. Maybe in this quieter repair year, we’ll get to a result!
The general idea is simple: roots like to grow down, looking for food and water. Give them a headstart in the down direction, and you should get better results. Earlier fruiting, bigger fruit, overall more productive plants, especially good if you have a shorter season like here, where fall frost will put a halt to the toms. But there’s a big tiny farming BUT.
Labor is that big thing. If you have hundreds of toms to transplant, especially in our heavy soil, digging that extra couple of inches actually takes time and effort that adds up. Having tomatoes a week earlier, if that proves out, won’t offset not getting the transplanting done on schedule in the first place. Adding extra work for a cool idea is a tough one on a hand-run farm that’s not optimizing in terms of thousands of tons of produce like a big commercial, mechanized farm.
I’ve usually gone the other way. Grow toms in plugsheets that would seem ridiculously cramped and tiny compared to the substantial home garden seedlings available for five bucks a pop at the garden center. Get them in the ground early, buried up to their first leaves. Frost risk? There’s always row cover! Let them get on with it from a young age.
Still, experiments are fun, and when you learn stuff by trial and error, first-hand, the knowledge usually finds a way to become useful. Hopefully this year, there will be a solid deep pot vs shallow result!
Peering down a rabbit hole
Not a literal rabbit hole, instead, the one that I encountered when just for fun I looked into sunburned leaf damage, like what appeared today on a single squash leaf. Sunscald during hardening off isn’t what you’re aiming for, but it happens and it’s never been a big deal. So long as the seedlings are well-watered and the roots aren’t getting cooked in their containers, they’ll be fine has been my experience. Still, since only one leaf among around three dozen squash and melon plants got burned, after several full days in the sun, and yesterday half overcast, I took a mild interest—if I was a lot busier, with hundreds or thousands of seedlings on the go, and everything else looked fine, it wouldn’t get a second thought. Odd one-offs happen all the time.
A bunch of reading and skimming of farm and garden blog posts, university agricultural extension papers, science mag articles, and scientific studies, and no answers. The sunburn itself seemed unusual, especially after a half-cloudy day. Of course, our SPF sunscreen-and-skin cancer training has told us that UV is still strong on cloudy days, but why did only one leaf get so toasted?
Then I discovered the UV spike. Not so widely written about, not as confidently stated as ~80% of UV makes it through clouds, but a real thing. When certain types of cloud pass in front of the sun, like perhaps the fluffy cumulus ones that floated by most of yesterday, the fringes of said clouds can act as a magnifying lens or filter that focuses and directs UV straight down, resulting in an intensity spike of maybe 25%. Could it be that one big early leaf hadn’t been shaded by the others on previous days and gotten more exposure and hidden damage, and just couldn’t take a day of high-powered UV micro-blasts, a few seconds each as the sun disappeared and reemerged, over and over. Hmm, that sounds maybe fairly reasonable…
Soon after, I lost interest—WHY would I want this explained? I could think of no good reason. I’ve found with tiny farming that learning is continuous and great, but what you choose to take in is also critical, sucking up everything is a waste of attention. The one burned leaf isn’t a mystery, it just clearly happened. And unless more similarly unusual things appear, I’m not particularly curious. The real thing to remember: harden off, a couple hours max outdoors the first day, and keep them well-watered and not boiling in their pots! When they get into the real ground, small ups and downs along the way will be forgotten, they’ll spread their roots and do just fine. Conditions in the field being favorable, of course!
Thigmomorphogenesis
Squash seedlings in a stiff breeze—gale-force wind would’ve made for a more dramatic image, but thankfully not. This bending and fluttering of leaves is another benefit, besides the sun, of taking indoor-started seedlings out into the real world.
Movement, like blowing in the wind, triggers the catchily named thigmomorphogenesis process in plants, where they dramatically toughen up after getting a little pushed around. It could be wind, a pummeling rain, animals or hands brushing by or moving them about. Makes perfect sense for them to armor up.
I’m not particularly into the details of how they change, develop sturdier stems and whatnot—tougher seems to sum it up just fine—but it’s good to know about (I used to use an oscillating fan in winter). And I really like the term. For most of my life, my casual thought was that knowing everything would be cool, kind of like AI tries to today. At one point, though, conveniently marked by a certain blog post, my thinking flipped to often wanting to know less. Not cheering for ignorance, just comfortably sticking with what’s necessary for the moment. So, thigmomorphogenesis—long, unwieldy, yet surprisingly easy to pronounce after a couple of tries!
Tomatoes just want to root
Most of us don’t spend much time at all looking at plant roots. Meanwhile, the things going on underground are quite wondrous. Take this humble tomato seedling, demonstrating a special power: adventitious rooting—a catchy way of saying they can grow new roots from their stems. Tomatoes, potatoes and peppers, all relatives from the nightshade family, have this ability. And? Well, if you have leggy tomato transplants, stretched from too much time indoors in tiny plug sheet cells, this ability allows for a neat trick. You can dig a little trench instead of a hole and lay the seedling on its side. Then, bury the root ball and most of the stem, gently curving up the last bit. Ta-da, a sturdy little transplant. I did this for a few leftover tomatoes two days ago. Today, I found one snapped off—wind? rabbit?—so I pulled it, revealing roots that had already started pushing out. It’s just another little bit of all that goes on in the hidden part of the garden!
Attack of the leek moth
Checking for scapes today, only a couple of days after the last all-good garlic check-in, and found absolute carnage thanks to a leek moth invasion. For years, I’ve heard about these voracious leaf devourers ravaging alliums—garlic, onions, leeks—in the general region, but they’d never shown up here. Until now. After hours of hand picking and squishing, the situation may be somewhat under control.
FACT-FINDING: I did a bit of quick research to get the bigger picture. Leek moths (Acrolepiopsis assectella) are nocturnal, operating in full darkness. They overwinter in plant debris, emerge and mate when the temperature gets up to around 50°F/10°C. There are usually three generations a year, around here in mid-May, June and July. The first generation grows up (fast, in around 3 weeks) and starts laying another round, and so on.T hat means, in unusually warm or cold weather, there could be more generations per year, or less. Each female has around 100 eggs, lays them singly not in clusters, usually on the underside of leaves near the base of the plant (but, naturally, look EVERYWHERE!). There’s of course lots more, but that’s what I need to know for veg protection—garlic under row cover (and it would be pretty safe to uncover them during the day).