to do this:
1. Upgrade your house at least once. Some garden plots will appear on your lawn.
2. Buy the watering can, fertilizer, and some seeds from the hobby shop.
3. Go back home. Tap on the garden plots. A "Plant..." menu will come up. Select the vegetable you wish to plant.
4. Tap on the same plot of land and tap "Tend".
5. Tap on the same plot of land again and tap "Harvest". You can now sell the vegetables at the Quickmart or use them for cooking.