It's difficult to definitively say which is the "toughest" flower among Geraniums, Wave Petunias, and Fuchsias, as "toughness" can mean different things depending on the context:

* Heat and drought tolerance: Wave Petunias generally have the edge here. They are known for their ability to withstand hot, sunny conditions and can tolerate some drought.

* Disease resistance: Geraniums tend to be more disease-resistant than the others, particularly against fungal diseases.

* Cold tolerance: Fuchsias are generally more cold-tolerant than the others, especially in temperate climates. However, all three can be affected by frost.

* Overall resilience: Geraniums are often considered the most resilient overall, able to handle a range of conditions and bounce back from some neglect.

Here's a breakdown:

* Geraniums: Highly resilient, disease-resistant, tolerate some drought but prefer consistent watering.

* Wave Petunias: Excellent heat and drought tolerance, but require more frequent fertilization and can be more susceptible to pests.

* Fuchsias: Beautiful but more delicate, preferring cooler temperatures and consistent moisture.

Ultimately, the "toughest" flower for you will depend on your specific climate and growing conditions.