How to plant leek seeds on balcony is as follows:

1. Prepare planting container: choose a suitable container for planting leeks, it can be a pot, flower box or planting box. Make sure the container has enough depth and drainage holes.

2. Prepare soil: Choose a soil suitable for growing chives, preferably fertile humus or flower-specific soil. It can be purchased at florists or gardening stores.

3. Sprinkle seeds: Sprinkle leek seeds evenly on the surface of moist soil. For small chive seeds, gently press the seeds to make contact with the soil.

4. Cover the soil: gently cover the seeds with a thin layer of soil, usually twice the diameter of the seed. This will help retain moisture and protect the seed.

5. WATERING: Water carefully using a spray bottle or watering can to keep the soil moist. However, do not overwater as this may cause the seedlings to rot.

6. Provide sunlight and sunshine: Place the container on the balcony to ensure that the leeks get plenty of sunlight and sunshine. Leeks can tolerate shade slightly better for their general needs, but still require some sunlight exposure.

7. Manage growth: Wait for leek seeds to germinate and grow into seedlings. Keep the soil moist and loosen and weed regularly to promote healthy plant growth.

8. Harvesting: leeks can usually be harvested after 2-3 months of growth. When the leek grows to the right height, just use scissors or knives to cut off the desired part.

Notes:

- Leeks like plenty of water, but avoid waterlogging and control the amount of water when watering.

- Maintain proper aeration and avoid over-wetting the soil.

- Fertilize regularly: apply organic fertilizer once a month to supply the plant with the required nutrients.

With these steps, you can successfully grow leeks on your balcony. Enjoy the delicious taste of homegrown fresh leeks!