First, go to the shop and buy a field. The shop's IC, so just roleplay your character and the Namekian shopkeep. Buy some seeds, too!
Once done, go to your field and write about planting the seeds. You can have one vegetable crop and one tree crop. You may have as much of each crop as you have the seeds for. Once done, you can add fertilizer, one use is for the entire field.
Then, leave. The soil is moist, so don't worry about watering.
The shop tells you how long until harvest.
When you harvest a vegetable crop (this is the name given to any non-tree plants. I'm aware Tomatoes are fruit.), you lose the plant and automatically get the Zenni. Staff will grade it like any other post, sobe sure to include all numerical data.
Just come back when time's up and harvest. Trees are different. They don't get exhausted when harvested, so they'll continue to produce yields.
