Bird Netting as a Cabbage Leaf Caterpillar Barrier

UPDATE: This idea is a complete failure–see the ugly details here.

Last month I sang the praises of floating row cover as an insect barrier. The only problem is that floating row cover retains heat, and so when our fall and winter days turn hot, as they so often do, it gets way too hot and humid inside the “tent.” So as Marshall McLuhan was fond of saying, “If you don’t like that idea, I’ve got others.” Specifically, bird netting.

I’ve got an untested theory that bird netting is enough to keep out the white butterflies that give birth to the dreaded cabbage leaf caterpillar, the only serious pest for us at this time of year. So far the bird netting seems to be working. I’ll note that it would be important to keep the leaves of plants well away from the netting so that butterflies can’t lay eggs through it. The best way to do this is by planting arches of wire or tubing over your garden bed, and stretching the cover material over those arches– like a covered wagon.

Netting has advantages over row cover: you can see and water through it and it’s more readily available.

I’m curious what you, our dear readers, think of the idea?

  • Mrs. Homegrown chimes in:  I’ll add that in the past readers have said they use tulle material as an insect barrier– you know, the stuff used to make tutus.

Row Cover as an Insect Barrier

It ain’t pretty but it works.

As one would expect, cabbage leaf worms love cabbage and nearly every other member of the brassica species.  Which  is why I’ve become a real fan of row cover material as an insect barrier.

The perp in question.

It rarely freezes here so I use the thinnest row cover possible, specifically a product called Agribon-15. If you live in a cooler climate and want to use row cover for frost protection you would use a thicker product such as Agribon-30. Johnny’s Select Seeds carries Agribon row cover in lengths as short as 50 feet–plenty for an urban or suburban garden. I’ve used both PVC pipe and chain link fence tension wire as support. I secure the row cover down with pieces of rebar and bricks to keep out skunks.

What cabbage worms become.

It’s not a plug and play solution, however. If it gets hot I have to remember to pull the row cover off. And the added humidity can cause outbreaks of aphids. But overall, it works great. I’ve found that I just need to use it when tender seedlings are getting established. Once they have a fighting chance against the cabbage worms I can pull it off.

Comopost, Compost, Compost

As if I didn’t need a reminder of how important compost is to a vegetable garden, note the tomato above. It’s on its way out, but it grew with no supplemental water in hard-packed clay soil contaminated with lead and zinc in a hot side yard. Why did it do well while the rest of my vegetable garden did not do as so good this summer?

Homemade compost.

I didn’t have enough compost for the rest of the veggie garden so I bought some at a nursery. The homebrew compost obviously had much more life in it. 

And life is the point. Soil is a living thing. Plants, particularly vegetables, need microbial life to thrive.

For more on the importance of microbial life read the USDA’s soil biology primer written by Dr. Elaine Ingham.

Don’t be so quick to clean up

A lot of magic happens in the “dead” parts of a garden. Flowers gone to seed feed birds. Dead stalks support important insect life–from spiders to pollinators. Fallen leaves and sticks give habitat to lizards and toads and mushrooms and myriads of invisible creatures.

Yet dead growth is not attractive to the human eye, and around about this time of year we’re all itching to make a clean sweep of all that brown stuff. I know I am, but this morning I was grateful that I’ve procrastinated thus far, because I saw a flock of tiny little gnat catchers (adorable!) feasting on whatever tiny bugs live on the scraggy stand of fennel standing in our front yard, and a couple of hours later I found a flock of house finches enjoying the withered heads of our long, long dead sunflowers. I almost cut those stalks down yesterday, and am so glad I didn’t.

It’s a balancing act. If your garden is in your front yard you pretty much have to be tidy to appease the neighbors. If you have a small back yard, like we do, it’s hard to avoid the temptation to clear the decks, because everything is right in your face. Blessed are those with big yards, because they might have the option to keep the areas closer to the house tidy while allowing the “back 40” to go to seed.

I guess all you can do is keep the little creatures in mind and put off the clean up as long as you can. Leave dead leaves and sticks on the ground year round. Designate small corners as wilderness. The more you support all levels of life in your garden, the more your garden will thrive.

New Zealand Spinach is the New . . . Spinach

Spotted in a neglected corner of our backyard: New Zealand spinach (Tetragonia tetragonioides). What’s interesting is that it self-seeded and grew with no supplemental water in the middle of summer in lead and zinc contaminated soil.  We’ve never been able to grow regular (and unrelated) spinach here. But there’s no stopping the New Zealand spinach. Due to the heavy metal problem we won’t be eating this particular specimen, but when I build our new raised beds you can bet I’ll sow some New Zealand spinach for next year.