ask PHS

I'm not sure exactly  what you might mean.  Neonicotinoids are insecticides, chemically similar to nicotine,  that are used to control sucking and chewing insects, soil insects, and fleas on domestic animals.   Neonicotinoids have toxic effects on honey bees, and some birds.  It is marketed under many brand names.  However, it is applied, so plants and flowers that have not been treated with  neonicotinoids should be safe.  And soil that has not been treated should be of no concern.  I would doubt that plants that you buy from a garden center for use in a home garden would have been treated. Agricultural crops seem to be the primary use of neonicotinoids. From a bit of research I have done, I have found that as of 2013 neonicotinoids have been used in the U.S. on about 95 percent of corn and canola crops, the majority of cotton, sorghum, and sugar beets and about half of all soybeans. They have been used on the vast majority of fruit and vegetables, including apples, cherries, peaches, oranges, berries, leafy greens, tomatoes, and potatoes, to cereal grains, rice, nuts, and wine grapes.  But these are crops that come to market.   I would think that you easily will be able to find plants that have not been pre-treated in any way that you could use safely.  A good garden center should carry a variety of plants, and organic plants would be safe.    Check with Meadowbrook Farms in Jenkintown, which is a wonderful resource with knowledgeable staff. http://meadowbrookfarm.org/  Good luck with this, and with your concern about safe and organic gardening that is not harmful to bees and birds and benficial insects.