The Direct-Seeded Experiment

In April amid the dozens of trays of plant starts and the commencement of the early outdoor growing season, I decided to question almost everything I’ve ever known about gardening. Well, at least question whether or not a pepper or tomato plant could grow and produce here in Minnesota if I direct-seeded them.

This has been a years-long curiosity for me, especially as we grow at this scale and are using a lot of resources to indoor seed start. I’m not growing any younger, but my youthful inquisitiveness commands I explore my craft in novel ways annually. And this felt like the right year to pursue this question.

I made sure my soil temperatures were above 55F, and I think they were more like 60F. This is good temperatures for the tomatoes, onions, and tomatillos, but too cold for peppers and eggplants. I expected staggered germination, with the onions sprouting first, tomatoes second, and so on. And that is exactly what happened.

On April 12, I went for it. In a corner of a low tunnel, I sowed:

• Sun Gold

• Plum Perfect

• Pink Brandywine

• Tomatillo

• Candlelight Pepper

• King of the North bell pepper

• Bastan Poblano

• Diamond Eggplant

• Patterson and Rossa di Milano onions

Germination Rates

Not surprisingly, the onions and tomatoes did best. Why I say this isn’t surprising is that I get volunteer tomatoes that will fruit in our garden annually, and onions are really cold hardy and thus I expected them to be a success.

I am honestly still surprised as how quickly these tomatoes established themselves. Not surprised about the tomatillo (far right) though — they germinate and sprint to the finish line.

Onions, tomatillos, and tomatoes all germinated within 4 weeks. Mind you, there were a few variables. First, I took the cover off this area pretty early on as the brassicas were in that bed and didn’t need cover. And second, as I’m rewatching my stories we had a brutally cold and grey April and I am convinced some of that slow germination was due to the really lousy spring weather.

The peppers didn’t germinate until about a week later. But I only got the poblano and candlelight to germinate. The King of the North and the Diamond Eggplant didn’t germinate at all.

Growing On

With the size of the garden and all the tours, I didn’t get to transplanting any of these vegetables as quickly as I’d liked. They got transplanted around the Solstice, and some of you may recall my tomatoes really suffered, especially the Plum Perfect. It is producing well, here at the end of September, which is not what I consider tomato season at all. But with more care in transplanting earlier, I think direct-seeding tomatoes is completely reasonable here in zone 4.

The tomatillo was transplanted over with the pumpkin patch, and I figured it would produce since we had two other plants growing in the garden. I was more growing it to see how it produced relative to my mid-April indoor-sowed ones. Tomatillos get really leggy indoors, and don’t need much of a head start inside. I think direct-seeded them is maybe even the wiser and saner way to grow these rambunctious fruits. Even after I’d pulled the other two purposeful plants out in August, this tomatillo is producing fruit, which is a bit odd as it’s widely known that you need 2 plants to be fertile.

The tomatoes and onions were the most successful of all. I was completely surprised to have ripe brandywine tomatoes around the 3rd week of August if memory serves me. And the sun golds that kicked into season in August came on the heels of so much disease pressure in our main tomato bed (likely our perennial foe Septoria leaf spot), and made us take pause and ask: should we be succession planting our cherry and heirloom tomatoes, too? I think the answer is emphatically yes! We will start fewer indoors, maybe aim to transplant 6 (2 cherries and 4 heirlooms) and then direct seed another 4 or so for August/September noshing. More on these kinds of garden lessons in a future post. There’s lots to hash out about this season and how it will shape next year’s garden plans.

All in all, the brandywine production was really not bad for a direct-seeded, May-germinated heirloom tomato that grows to 1 lb or more.

Also, in early September I found some ripe candlelight peppers underneath the octopus of a paste tomato, Plum Perfect. So small hot peppers seem doable direct-seeded here. And I’d guess, if I can get them to germinate, a small bell like an Alma Paprika would also be well-suited to this future study in direct-seeding your summer crops.

What’s Next

Next year I am hoping our new cold frame will be ready in time to have a dedicated space to explore direct seeding more hot season crops that transplant well. A cold frame will get warmer than my low tunnels do, I suspect, and thus should be a more consistent space for getting more serious about direct seeding as an alternative to indoor sowing, potting up, hardening off, and transplanting.

I will continue with my densely planted seedlings, make a more concerted effort to thin and transplant earlier, and hope I can crack the code on King of the North bell peppers too. Eggplant germination would be the cherry on the cake, if that can happen. The tricky part there is that the seeds need light to aid germination and I think they end up running off from overhead watering. Perhaps I could sprout them before planting the seeds, but that sort of negates the whole point of this being a less involved growing process.

Other crops I don’t usually direct seed but might try are cabbage, brussels sprouts, kale, broccoli, and cauliflower. I have successfully direct seeded napa cabbage, kohlrabi, and bok choy, three other key vegetables in our garden in spring, early summer, fall, and into winter with storage (these all store really great!).