When To Plant The Garden: A Natural Experiment

Food production is an important part of prepping. As I write this in May 2020, COVID has motivated a lot of people to plant a garden. But when’s the best time to put it in?

Advice on when to plant

Advice on when to plant is abundant. Way too abundant, in fact. Here are some suggestions I’ve heard just lately — and how they’ve worked out for me:

• Plant the first lettuces on Valentine’s Day, even if you have to dribble them on the snow.
• Never plant before Mother’s Day 
• Follow the Farmer’s Almanac 
• Go by the last frost date for your region
• Plant within two days of the first full moon after the spring Equinox
• Plant when your daffodils quit blooming

So how’s all that work out when tried?

Of these, I’ve tried every danged one. I live in northern Missouri; about at the Zone 5b/6a border. (Planting zones are assigned by climate; you can find out yours by clicking here. Important to know when deciding what and when to plant.) So how’d it go?

• Plant early spring crops on top of Valentine snow! And then plant them again when nothing sprouts after the snow melts and nothing pops up.
• Never plant before Mother’s day. Ok, so work was really hectic and it was an accidental experiment, but still…summer crops were happy. Early spring crops poked their shoots up then wilted in horror at the heat; or grew nicely for about a week then bolted. (Bolted means they went to seed; but the image you’ve got of a plant running away from weather it hates works pretty well too.)
• Follow the Farmer’s Almanac; they always know! No they don’t. They hit the optimal week one year of the three I tried it. One year they got me frozen out; another I missed two great growing weeks. But hey, they *averaged* perfection, right?
• Plant at the full moon after the spring equinox: Works pretty well in my zone. Of course, that happens to be almost exactly the same time called for by my favorite:
• Plant early spring crops a couple of weeks before your average last frost date; plant summer crops a couple of weeks after average last frost.
• Oh wait, the “Plant when your daffodils are done” method? Um, I’d still be planting. I can grow vegetables pretty good. Flowers, not so much. Daffodils are kind of done as soon as they figure out they’re in *my* hands.

A Natural Experiment in when to plant

One of the things I’ve learned in my science career is that some of those things that “everybody knows” turn out to just have been made up. Everybody believes them because other people say them. Like that whole “drink 8 glasses of water a day” thing you find in half the diet advice in the world? Turns out nobody tested that statement for the first few decades of its existence; and while getting plenty of fluids is helpful, the “eight glasses” thing was just a rough estimate some dude tossed out that got taken as gospel. Is the planting advice like that?

This year provided a “natural experiment”. That’s what a scientist calls it when nature just happens to provide just the kinds of conditions the experimenter wanted to look at; and the experimenter just has to pay attention (and be wary about uncontrolled factors).

“Natural experiment” in this case is a nice way of saying “GAH what do you MEAN with a hard freeze in MAY, Mama Nature? Our last frost date is usually mid-April!!” On top of that I’d intentionally started planting the summer crops earlier than I normally would, to see if I could sneak in a longer season. I’ve plenty of seed and a good cheap greenhouse on hand, so I figured it was a “low cost to fail” thing to try.

Upshot is, I got my garden fully planted at my earliest date ever. Right before they announced the late freeze warning. Sigh.

How did my garden like it when they got put in the “natural experiment” freezer?

Opinions differed. Plants divided themselves into two major groups, with some wafflers.

“We laugh and enjoy when morning sun sparkles off the frost!”

Happily, many of my plants fell into this category: 

• All of the lettuce varieties, radishes, and carrots
• Other greens: spinach, chard, spinach mustard
• All the herbs: oregano, basil, dill, rosemary, sage, lemon balm, mint…
• All brassicas: broccolis and cabbages is what I had out this year
• The lily family: Onions, garlic, chive (I grow the latter two as perennials, so they’re out there in every season)
• All the peas (snow and shell) and beans (several varieties, bush and pole) (Note: The beans are a traditional summer crop. They took a loooong time to sprout in the cold early soil, but they did come up and look ok today.)
• Potatoes (I don’t remember the cultivars; some red and some white late-season varieties I grew last year. I had a couple left over in the potato bin and just stuck them in the ground to see what would happen.) Also some sweet potato plants.
• Perennials including asparagus, strawberries (now in flower), apples, cherries, and Juneberries (past flowering and starting to set fruit). Raspberries, blackberries, and grapes look fine but haven’t flowered yet anyway.
• Surprise! One cultivar of tomatoes made this list: Early Girl. I *love* this cultivar; produces early and often, lasts all summer, good tasting, disease resistant. One major bummer: It’s a hybrid, not an heirloom; so seed saving is unreliable.

The peas, radishes, spinach, lettuces, and garlic Laughs at the frost! The gnome may have helped.

Bonus! I planted these things so early this year I’m already awash in great salad fixings!

“When the frost comes, what will we do?” “We DIE!”

Ok, the summer crops I was being ambitious with often fell into this group. I’ll be hitting the greenhouse again later this week to restock on:

• Some tomato cultivars, including Rutgers and the (extremely productive and tasty) SuperSweet 100s. Sadly, the Romas I grew up from my own 2017 crop bit it too.
• Most of the cucumbers, squashes and melons. 

This is a Roma tomato, after a night’s frost. It was a healthy seven inches the day before. The weeds survived. Ain’t that the way of it?

The Wafflers

Some things look unhappy but may recover: zuccini, a couple of tomato cultivars, and various sweet and hot peppers. Maybe even a cucumber or two, if I get lucky.

So when should you plant?

How much can you afford to lose? 

If, like me this year, some losses are easily replaced and you value an early crop, you might plant early… 3-4 weeks before your last average frost date for early spring crops, about the average last frost date for summer crops.

If all you’ve got are some starts you spend the last six weeks tending, that can’t be replaced in a timely way, I’d suggest being about 3 weeks more conservative than that. 

I’m hoping my lists of what’s happy and what croaked will save you learning some things the hard way.  Also, although I’m just one person in one planting zone, at least it’s not just “people always say this”. I don’t disrespect farmer’s wisdom about growing crops; but Grandma might not have lived in your climate zone, and that’s a big deal.

Crop covers and other help

Yeah, I could’ve put a frost cover over whole gardens, or jugs over each plant. I could’ve put jugs of warm water (clouches) under the cover to help further. I’ve done all of these things before. They help, but are a pain in the tail. They also would have ruined my natural experiment. So I didn’t do any of that for this last frost.

I might have also built a high hoop tunnel or other more permanent structure for protection. If I lived further north or knew I’d get no spring veggies until I grew my own, I’d do that; they work nicely. Just build them robust if you build them at all. I’ve fallen for the “This will probably hold up” line of reasoning. That approach *positively attracts* high winds.

But my date’s already passed for the year!

If you’re in the temperate zone of the northern hemisphere, it’s not too late for most crops. You might miss out on the ones that hate heat (like radishes and lettuces); but even then there are more summer-loving varieties and you can give them some shade. You’ve got a shot.

Later plantings at this stage usually means a slightly shorter harvest season, not an outright fail. As a bonus, you may miss some pest problems. So go plant!