How do you keep caterpillars off your brassicas?

Question

How do you keep caterpillars off your brassicas?

Answer 1

If you use chemicals, Sevin works well.  For more organic methods, try Bt, the bacteria thurengiensis.  This bacteria kills most caterpillars the natural way with no effects on humans.

Answer 2

Brassicas are a huge attraction for Cabbage White butterflies so there is not easy answer to this one other than to check daily & remove by hand. Tedious - but successful. Good luck. h

Answer 3

try putting some flowers around the the patch for them to eat instead

Answer 4

I've used flour to suffocate the cabbage loopers. If I see evidence that they are around, I just sprinkle some flour on the leaves when they are wet. When the caterpillars crawl up onto the leaves, they get pasted & fall off.

If you see their eggs on the head of the cabbage, pour sour milk on it & it'll kill the eggs. I learned this years ago from reading "Organic Gardening" & "Mother Earth News". You can also handpick the caterpillars if you see a few.

B.t. (Bacillus thuringiensis), an organic insecticide derived from a bacterium that occurs naturally in soil,  (sold as Dipel, Bactur, Sok-Bt or Thuricide), is used as a control against the caterpillars.

http://www.uri.edu/ce/factsheets/sheets/...

http://www.myorganicflowers.com/bugs.htm

Forum on using  B.t.as a pesticide against caterpillars:

http://forums2.gardenweb.com/forums/load...

You can prevent moths from laying their eggs by using a fine mesh fabric to cover vegetables. You can use mosquito netting,  old window screens, tulle, or a nylon type of material which is hard to penetrate. Tulle fabric, which is used for bridal veils & party favors, can be bought in department stores, Wal Mart & craft stores.  (BTW, even if you punch holes in it, plastic row covers may create too much heat & humidity in the summer).

Netting to keep out insects:

http://www.wisegeek.com/what-is-tulle-ne...  

http://www.gardeners.com/on/demandware.s... netting

Fine Mesh Netting  said to  last 7-10 years:

http://www.gardening-naturally.com/acata...

http://gardening.yardener.com/Solutionsf...

Fine mesh netting can make nice protective row covers like this:

http://www.pvcplans.com/RowCvr.pdf

http://carletongarden.blogspot.com/2007_...

Encourage beneficial insects & be careful not to acidentally destroy ladybugs & lacewings, etc. If you find dead caterpillars with a large mass of white or yellow cocoons nearby, the cocoons are from a parasitic wasp... an enemy of the cabbageworm that feeds on the eggs and young larvae.

http://forums2.gardenweb.com/forums/load...

Attract small insect-eating birds by providing safe nest sites and a constant supply of water. Insect predators of caterpillars include: assassin bugs; tachinid flies; paper wasps, which chew up caterpillars and feed them to their larvae; lacewings and ladybirds eat moth eggs; tiny trichogramma wasps parasitise moth eggs; other tiny wasps like Apanteles sp. parasitise the caterpillar.

http://www.greenharvest.com.au/pestcontr...

Companion planting: Sage (Salvia officinalis) planted with cabbage protects against Cabbage Moth,  Flea Beetle, Slugs; Thyme  protects cabbage against Cabbage Worm; Oregano, Hyssop  & Mint protects against Cabbage Butterflies:

http://www.dgsgardening.btinternet.co.uk...

http://hgic.clemson.edu/factsheets/HGIC2...

Neem is a non-toxic, biodegradable substance, which has natural insecticidal properties. It discourages caterpillar by making the plant unpalatable to them.  I was pleasantly surprised to learn that the Persian Lilac is closely related to Neem, & that the dried leaves and twigs have been used for centuries to protect cloth, books and leather. The seeds possess insecticidal propreties as well. Its leaves are insecticidal, repellent, antifeedant, growth inhibiting.

http://www.indianscience.org/essays/t_es...

http://www.regional.org.au/au/esa/2001/0...

Knowing that the caustic nature of sour milk is what kills the eggs or that coating the caterpillars suffocates them, helps make sense of these methods. Since the nasty taste of Neem keeps the caterpillars from eating plants, some people make similar nasty-tasting sprays of hot pepper & garlic to do the same thing.

Forum about getting rid of cabbage pests. One suggestion is a "neem/red pepper/bergamot/soap and water concoction".  Another suggestion is "don't put catnip or lavender anywhere near members of the cabbage family. In fact, place them far away to lure moth and caterpillar pests away".

http://www.yougrowgirl.com/forums/viewto...

Capital Community Garden's  'Garlic & Pepper Spray'  control uses 6 cloves of garlic, 1 Tbsp dried hot pepper, 1 minced onion, tsp pure soap (not detergent) mixed with 1 gallon hot water:

http://www.cdcg.org/pests.html

Good luck!!!   Hope this is helpful.

Answer 5

A hot daily shower with a good quality soap and vigorous drying will generally do the trick.