Answer: hotbeds

AnswerCrossword Clue
HOTBEDSFertile spots
HOTBEDSActivity centers
HOTBEDSSources of unpleasantness
HOTBEDSBusy places
HOTBEDSGlass-covered enclosures in greeneries
HOTBEDSPlaces favoring rapid growth.
HOTBEDSGardener's concern.
HOTBEDSPlaces for seedlings
HOTBEDSCenters of activity
HOTBEDSBreeding grounds
HOTBEDSPlaces of great activity
HOTBEDSAreas of rapid growth
hotbedsglass-covered, heated bed of earth for growing plants
hotbedsplace where something thrives and spreads
hotbedsHOTBED, a place favourable to rapid growth