I put in a butterfly garden this year and I know you can't use any pesticides but I was wondering by chance if there is a homemade solution that I can spray on plants for diseases/pests that won't harm the butterflies. Thank you.
First, congratulations on providing for butterflies, symbols of natural beauty and important pollinators. The short answer is no however to any homemade solutions/potions. Butterflies are fragile and highly sensitive to chemicals of any sort and you find advice not to use anything on any butterfly website that you visit. You can expect to see numerous insects in your gardens on occasion but not to fret. Many or most do no harm. Retired MSU entomologist Tom Ellis declared years ago that "90% of the insects in your gardens are in there chasing the other 10% that will damage your plants. Leave them alone and let them do their job." Aphids are a case in point. They can become a large presence quickly but there are many other predator insects that will find and devour them. Also, many insects are plant specific, meaning you find them on one plant specie only. Diversifying your plant selections with numerous varieties makes that much less of an issue. And using plants native to your region will prove hardier with fewer disease issues. http://migarden.msu.edu/flowers/native_plants
Most butterflies are plant specific in regards to laying eggs. Choose host plants for the butterflies you wish to attract.
Here are a couple of links to more info on butterfly gardens:
Another helpful idea is to use pest repelling plants: http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/blog...
Thank you for all the links! I put in a 36' x 15' butterfly garden and used a lot of different native plants hoping the diseases and pests would be fewer. My biggest problem this year is the 4-lined plant bug. Last year, they were only on my oregano. This year, they are on several plants they are not supposed to bother and they are destroying my plants.
Four lined plant bugs can be a big headache but are not especially noted for causing plant death. They should be nearing the end of their feeding cycle by early to mid July when they turn to mating. Adults do not over winter but lay eggs for the next growing season, often on herbaceous perennials. This is likely what they did in your garden since you had them last year. Breaking that cycle would be your goal. By definition, herbaceous perennials die back to the ground each year so a good fall cleanup could be helpful in getting rid of at least some eggs. I've not seen the eggs but they are supposed to be very visible, as you will read at this link:.
This site suggests using insecticidal soap, the least toxic of pest controls:
This is the best writeup I can find on insecticidal soaps:
The downside might be the soap has to come in contact with the insect, a tricky task with evasive four lined plant bugs.
Bottom line, it's a judgement call on your part as to using anything stronger or not. Most sites suggest the feeding damage is temporary and that plants will recover.
Again, good luck!