as long as u plant em near plants with the around the same color leaves and type of leaves...u shud b fine...ive actuly cut my leaves from the 1st week of growing..to make it less pot lookin
naw they dont send off wavelengths. around here they just take a shit load of area photos. but if u dont have a huge ass feild dont worry about it. speacliy if it isnt on your property.