Brassicas: what do I have to do to grow a good one?

I have been gardening vegetables for decades. No till, heavy mulch, even composting and swills and teas. But again this year my efforts were mostly consumed by cabbage butterflies and flea beetles.  Yes, I've used many hoses and tents of mesh. Yes I've rinsed with the hose. No I will not spray with chemicals.  I have used neem though.
I'm in zone 3b. Studying regenerative farming.  The belief that if I get the soil right the pests will leave my plants alone leaves me scratching my head and continuing to search for the holy grail of soil health.
Currently thinking: trace minerals and looking at Steve Solomon.  I understand (especially on our 100+ year old family farm) that agricultural chemicals of the past have rendered zinc inert or so I am told. Also get that some say the minerals are all still there, we need only the bacterial and fungal friends to deliver them.
Anyone get the brassica soil formula right? I wanna learn.  

There are many different species of brassicas with many different seasons of productivity, physical shapes, growth habits, chemical deterrents, etc.

I've never seen a cabbage worm eat the bulb of a kohlrabi. They don't eat the turnip leaves or radish leaves, or the roots. They blow in on the wind mid-summer. Anything that is harvested before then doesn't get eaten. Anything that is harvested after the fall-frosts begin doesn't have them on at harvest. The green caterpillars show up better on red leaves, and are therefore more susceptible to predation. I keep nesting sites for predatory wasps.

At my place, flea beetles are only a problem in very early spring, (before the irrigation system becomes active -- and they drown?) The flea beetles prefer some varieties over others. I've wondered about planting sacrificial crops to distract them.

Neither flea beetles nor cabbage moths seem fond of the mustards or arugula.

Delila Jahn-Thue wrote:The belief that if I get the soil right the pests will leave my plants alone leaves me scratching my head and continuing to search for the holy grail of soil health.

This is an oft-repeated permaculture article of faith that is not matched by my observations.  In fine, I don't believe it.

IMO the key to growing successful vegetables in general  (I am not currently in a great climate for brassicas, although they do pretty good spring and fall if I get the timing right) without chemicals or sprays has more to do with building a garden habitat that supports a whole ecosystem of pest predators.  Where I am, that means snakes, skinks, frogs, toads, spiders, praying mantises, dragonflies, a hundred other hunting bugs I can't name, a zillion kinds of birds ... you get the idea.  If I can get enough "stuff that eats bugs" living in my garden, the pest pressure drops off to "tolerable" -- not zero, but tolerable.  I do dozens of things (mostly habitat and water features) to encourage all these visitors/denizens in my garden.  And I usually can walk up to any given plant and spot the critter that claims it.  Usually it's a small frog or a big spider.  I call them my "integrated pest management heroes."  

Now, all that said, I don't know for sure how far north this translates.  I grew up on the Yukon River near the Canadian border (zone 2ish, depending on which map you look at) and I was shocked at the biodiversity that I discovered when I moved south.  We didn't have much pest pressure in our gardens but we also didn't have most of the things that EAT pests in my Oklahoma garden.  I remember cabbage bugs, but I don't remember my mother ever losing anything to serious pest pressure.  There may be some sour spot (opposite of a sweet spot) where there's too many pests and not enough pest eaters.

Here there are 3 major pests of large brassicas the large and small white butterflies and the diamond backed moth. I use butterfly netting which has a mesh size of 8mm which stops both the white butterflies but it does not stop diamond backed moths as they are way to small. If I wanted to stop them I would need to use a fine row cover a 0.8mm mesh that can also be used against carrot fly.

Flea beetles like dry soil so keeping the soil moist helps with them and fast growing plants will outgrow them. I don't worry about them on radishes for me as they only make holes in the leaves, on radishes for sale I try to keep the ground wet to deter them (not hard in this climate)

And then of course there are slugs and snails which love the damp soil and shelter the large cabbage leaves offer. I've shown pictures of my collection buckets on here before!


As to soil health "curing" pests I am also a non believer. I really dislike it when people state that nature doesn't need pesticide/net/etc yes but go look at the wild plants, every single one will have pest damage. So long as it doesn't stop the plant reproducing nature doesn't care. It's only because we don't want that bit of extra protein in our broccoli that we need nets!

Trap crops are a possibility but they must be destroyed at the right time, otherwise you are just breeding pests. There is a dead end trap crop for diamond back moth that has been trialed and shown to work, I personaly have not gotten round to getting seeds but I really should Barbarea vulgaris is the plant you want, Diamond backs prefer it to crop brassicas but it lacks something their lava need so they die before maturity, as a bonus it has good flowers for insects, on a negative it can easily become a weed.

I have that same problem with the cabbage butterflies, they live here in great swarms. One thing that helps a little for me is not to plant in a monoculture patch but instead stick them around here and there. Even letting some weeds grow I guess helps hide them some but still there are so many of the worms it is really hard to get nice cabbage or broccoli.

I've been trying to develop a landrace that is highly resistant to cold so as to mature in late fall or even winter when the worms are not a problem. Only limited success on that so far as mostly only kale overwinters for me. This year I have a mixed up patch of mostly cabbage and brussels sprouts and broccoli that I started back in early August and now that it has frosted a few times has recovered from the worm damage and looks beautiful. Also lots of volunteer kale around here and there. Last few years I started the later and they were too small to make it. Fingers crossed something will survive to make seeds next year. Already some cabbages have had a little frost damage but the ones with wrinkled leaves and the red ones all look great so far as does all the broccoli and brussels sprouts.

I'm mostly just looking for winter hardy and therefore worm proof greens so I don't care if the survivors cross up in weird ways next year.

Preliminary testing (aka I tried it out this year) has shown that some ducks quite like cabbage caterpillars and will self harvest if allowed.  This summer my four ducks were allowed in the veg patch under supervision, and also did a good job cleaning up slugs and snails on the empty plot last winter resulting in less damage from those this season.  The ducks didn't seem to go much for the green caterpillars, mainly the black and yellow ones--a camouflage/eyesight issue maybe?

G Freden wrote:Preliminary testing (aka I tried it out this year) has shown that some ducks quite like cabbage caterpillars and will self harvest if allowed.  This summer my four ducks were allowed in the veg patch under supervision, and also did a good job cleaning up slugs and snails on the empty plot last winter resulting in less damage from those this season.  The ducks didn't seem to go much for the green caterpillars, mainly the black and yellow ones--a camouflage/eyesight issue maybe?

That's really interesting I assumed the black/yellow ones were poisonous or at least bad tasting.

Skandi Rogers wrote:

That's really interesting I assumed the black/yellow ones were poisonous or at least bad tasting.

Well, my chickens won't touch them!

I have a tree perimeter on east, north and west sides of the garden.  Lots if borage, comfrey, strawberries and asparagus grow interpolated with tomatoes and carrots.  Also many perrenial flowers on the edges. Wet enough that slugs are large. After heavy frost this year I let the chickens graze this garden as well as the adjoining orchard. There is heavy clay but the growing beds have been heavily amended. Visitors have called my garden a jungle so there is no shortage of confusion and distraction for pests.
Anyone ever ammendmemded with trace minerals or done lab soil testing? I know our ancestors heavily tilled and weren't afraid to dust with ugly chemicals. That can do long term damage.  I have applied lots of flax straw and wood chips in the past. Woodchips have mostly been consumed.

I've also had wildly varying results with brassicas on the same land from year to year. I assume it has to do with weird temps and precipitation changes. I've had years when I've gotten amazing brussels sprouts, and then never again. Even my collards some years are just disastrous (while the kale in the next bed is gorgeous). I used to get gorgeous mustard, then this year planted it and it was infested with what looked like flea beetles!! I thought nothing ate mustard!!! Keep trying, there are lots of variables.
If you have access to soil testing, it certainly can't hurt. Neither can improving your soil with whatever you have access to. I add all sorts of goodies (stone dust, lime, compost tea, seaweed, ash, rabbit manure) and usually have to do some sort of aphid control when it's dry (usually, a soapy oil spray works well enough).
I live in an area known for broccoli and cauliflower. When I ask people about growing without sprays the response is always "that's not possible". I keep trying, but row covers seem to be imperative.