The Greenhouse removes normal seasonal crop limits, which makes it one of the best places to build a stable long-term growing setup.
Choose crops for permanent space
Because Greenhouse tiles can be used all year, crops with repeated harvests or high long-term value often benefit more from permanent placement than one-time seasonal crops.
Plan sprinklers before planting
Design watering coverage first. A clean sprinkler layout prevents having to remove mature crops later just to fix field efficiency.
Do not fill every tile immediately
Leaving temporary space can be useful while your seed supply, sprinkler tier or farm strategy is still changing.
Connect Greenhouse output to processing
If Greenhouse crops feed kegs, preserve jars or other machines, size the crop area around actual processing capacity. Producing far more raw goods than machines can handle creates a backlog.
Use the Greenhouse as a stable system
The biggest advantage is predictability: year-round production, repeatable watering and a consistent supply for artisan goods, gifts or cooking.
Source: Stardew Valley Wiki — Greenhouse.