Question
my problem, my wife and i found a white mold all over the shrubs hedge that was infested with wasps? i therefore used a wasp spray to kill of the wasps and now the shrub hedge is completedly dead and is spreading to the other hedge 5 feet away. so is this something that can spread to other trees and shrubs? and should i remove all the dead shrubs and dig out and remove the roots?

Answer
Sounds like powdery mildew.

Powdery mildews, as the name implies, often appear as a superficial white or gray powdery growth of fungus over the surface of leaves, stems, flowers, or fruit of affected plants. These patches may enlarge until they cover the entire leaf on one or both sides. Young foliage and shoots may be particularly susceptible. Leaf curling and twisting may be noted before the fungus is noticed. Severe powdery mildew infection will result in yellowed leaves, dried and brown leaves, and disfigured shoots and flowers. Although it usually is not a fatal disease, powdery mildew may hasten plant defoliation and fall dormancy, and the infected plant may become extremely unsightly.

In many cases, powdery mildew diseases do little damage to overall plant health, and yearly infections can be ignored if unsightliness is not a major concern. For example, lilacs can have powdery mildew each year, with little or no apparent effect on plant health. On some plants, powdery mildews can result in significant damage. Thus, fungicides must be used to achieve acceptable control. For best results with fungicides, spray programs must begin as soon as mildews are detected. Spray on a regular schedule, more often during cool, damp weather. Use a good spreader-sticker with the fungicides. Be sure and cover both surfaces of all leaves with the spray. Fungicides generally recommended for powdery mildew control include: Triadimefon (Bayleton, Strike); Triforine (Funginex), Thiophanate-methyl (Cleary's 3336, Domain# and Propiconazole #Banner).

IF the shrub is dead I would cut it at ground level --the fungus will not spread from the dead shrub.Unless the roots are in the way to re plant shrubs no need to dig them up