holes in bean plants under row covers
About two weeks ago, I planted several green bean seeds through landscape fabric (which I use throughout the garden) and immediately covered them with floating row covers. I anchored the row covers with long boards and bricks. The plants sprouted fine, but now they have holes in the leaves. Some leaves are bitten on the edge, some have holes in the middl. The damagei s extensive. What is eatingt he plants, and how can I control them? I prefer organic controls. I have Bt and spinosad and DE available.
It's likely that, with this moist weather, the culprit is slugs. They would hide during the day, especially under the boards and around the bricks. Here is help with slugs: http://extension.umd.edu/hgic/slugs-and-snails-vegetables
If possible, remove the row cover to let the area dry out a bit, too.
Thanks. I don't want to remove the row covers ( except maybe for short times when I'm right there ) because I'm trying to protect the plants from bunnies, groundhogs, and deer. Do you have a suggestion on how to hold row covers down without boards or bricks which I understand provide hiding places for slugs?
Will Bt sprayed on the leaves or around plants kill slugs?
Your publication suggested a barrier of DE. We have some that we use in the swimming pool sand filter. Is that type of DE ok to use in the garden?
You could hold the row cover down with landscape pins or staples. They look like big staples (u-shaped with long legs) that you push into the ground.
The type of DE that you have is not what you want. You want DE that is an agricultural product. It is super fine like flour to the touch, but it is microscopically sharp to insects.
Here is our page on beans that is quite helpful: http://extension.umd.edu/hgic/plants/beans
Thanks I have landscape anchor pins but didn't use them because they punch holes in the fabric and i thought bunnies could wiggle undert he gaps between the landscape pins (unless I spaced them so close that lifting the row cover to harvesta nd monitor plants would be difficult). But thanks for the suggestion.
Can you address the question of using Bt to control slugs and other garden pests ? Is this not a good idea? I have liquid BT and a small pump sprayer.
No. Bt only works on small caterpillars.
See control options on our slug page here: http://extension.umd.edu/hgic/slugs-and-snails
Diatomaceous Earth (the agricultural product, not the one used for swimming pools) is useful.