Tansy companion planting near squash.

I have squash bugs tearing up my crook-necks. I want to plant some Tansy to keep them away. How far away from the squash can I plant them and still expect successful pest free results? Tansy grows up to 6' tall. Is it a good idea to plant them in pots so I can move them around? Does planting them in pots limit the height they will grow?

I tried it and it did not work!

Good to know.

Deej.

Maybe diatomaceous earth? it is such a lightweight powder it is hard to apply. Don't breathe it, either.

Heather Y.

Diatomaceous earth helped lower the number of plants in my garden that were affected negatively by insects. Like HeatherY said, don't breathe it in. Be careful not to get it into your eyes, either. I used goggles, a dust mask and plastic coated gloves when I applied it. It is made of the exoskeletons of microorganisms called diatoms and they are microscopic, but sharp. They lacerate the body's of insects and they then dehydrate. Keep in mind that diatomaceous earth is not picky, and will kill beneficial and pest insects alike. You'll want to purchase food grade material and not the stuff that is used in filters. Food grade diatomaceous earth is okay to ingest. I was also careful not to have my dogs out and running around when I was applying the material. It is very light weight and I was worried that it may blow around and get into their eyes or that they might inhale it.

I used diatomaceous earth for a number of years twenty odd years ago because of advice in Mother Earth News. There was a significant reduction in pests as well as bees, wasps, ladybugs and beneficial ground beetles. I believe it kills fireflies too. For these reasons I don't use it today. My garden is not 100% organic (I use Daconil fungicide) but d.e. has longer range non-specific effects than, say, neem or Spinosad, IMO. It seems to be very popular with market gardeners here in GA because it's less expensive than comparable certified chemicals and it is organic. Its mode of action is more easily understood by the lay person than a central nervous system exciter like Spinosad which is also organic.

Great info, Laurel

Spinosad is used in a flea preventative called Comfortis as well as in a heartworm/flea preventative combo called Trifexis (along with milbemycin oxime) for dogs :) If it is something that I would give to my dog, then I guess I'd be okay with it in my garden. It has had a higher number of vomiting side effects than the other chemicals that we have used on dogs in practice, though. I am an LVT :) It leaves the bees, and other beneficials alone?

No it's an insecticide, it kills the good and the bad. It can't tell the difference.

But its primary mode of action is through the gut of chewing insects and negligible for direct spray. So, if you spray during hours when beneficial insect activity is low (very early or late in the day) and the product has time to dry, the impact is low.

As for the original question about tansy; I've found it somewhat effective but not very.

Too hot for tansy to do any good here, tried it- planted at base of my cukes.
Eggshells can do same as DE. In coffee bean grinder, til powder and hand apply to bug you want gone. Flour is candy to some bugs- self rising type- and they cant live thru the gluten. Most any bug on my veggies has trespassed and was unwelcomed- so all die. The beneficials Are overwhelmed to start with on my veggies.