
Red Thread and Pink Patch are two different fungi that often appear together in turf under the same environmental conditions. These are usually found in turf when the weather conditions have been cool and moist. Although these are funguses, fungicides are not recommended except in extreme cases. It is possible to reduce red thread through good lawn care practices.
Core aeration can help loosen compacted soil and allow
water to penetrate deeper in the soil.
The soils pH should be maintained at between 6.5-7.0.
Prune trees and shrubs to allow more light penetration
and air circulation.
Avoid frequent watering late in the day.
Once the weather conditions warm up and are drier, both fungi should disappear without causing much damage.
More info on Red Thread from Cornell University