Words are: "cars" and "bulbs"
- Cars need KEYS to start.
- This sounds like QUAYS, where boats are tied.
- Boats are used to catch FISH.
- Fish are sometimes kept in BOWLS.
- Bowls is a game played on GRASS.
- Grass is found in many GARDENS.
- In gardens people plant BULBS.
Source: The Oxford A to Z of Word Games