Q & A: Insects

praying mantisGot a gardening question? Ask Susan! What follows are reader questions. Each time a new one comes in, I’ll add it to the top. To ask a question, drop me a note at Susan@susansinthegarden.com.

Q: I planted a 12 foot row of turnips and another one of spinach in the same raised bed in May, separated  by 12 inches.  I got no usable items from either.  The turnips were full of small worms.  It was not like an onion or radish that might have a small hole that you cut away to use the rest.  It was totally unusable.  SS, Spokane

A: It sounds like the turnips had root maggots in them. Next time you grow them, you might try covering them with some floating row cover as soon as you plant them in order to keep the adult fly from laying its eggs on them.There is an information page in my Organic Pest Control Guide that explains how row covers work.

Q: Susan, do you know of any organic spray to stop leaf miner activity?  I forgot to put a floating row cover over the pony-pack of chard, and now the leaves are being eaten up one at a time. TM, Spokane

A:  That’s a shame! I don’t know of any organic spray that will work, esp. since the leaf miners are in between the cell layers of the leaves. Maybe you can pull off the infested ones, cover the plants, and see if they’ll do OK from that point on? And for next year, be sure to use a floating row cover as soon as you plant your chard (or spinach or beets, for that matter) so you won’t have to deal with those pesky insects.

Q: Susan, our crops are being decimated by earwigs. I can’t believe what has happened to my beautiful basil plants. There is literally nothing left but a few “strings.” Do you know how I can control them organically? Thanks! LW, Spokane.

A: You can try using diatomaceous earth (DE), which you can find at garden centers. It looks like flour, although it’s actually made from the fossilized remains of diatoms (algae). Here’s how it works: even though we can’t feel it, there are tiny sharp edges in the diatomaceous earth. You sprinkle it around the plants, an insect walks on it and their skin gets punctured by the sharp edges. Then they essentially dehydrate and die. I think it’s worth a try. This is organic, by the way. I had a problem with pillbugs nibbling on the stems of my cucumber and melon seedlings, and DE worked really well. One earwig-trapping method that we used a few years back involves taking a piece of cardboard and folding or rolling it a bit. That will expose those openings in between the layers that make up cardboard. You put it out in the garden in the evening, then pick it up in the morning and, hopefully, it will be full of the little stinkers thinking they’ve found a lovely place to hide until nighttime. And of course, you then toss it in the trash. I hope this might work for you. Good luck!