I live in Toronto on 4th and top floor or an apt. My window faces south with lots of sun and light from noon to late afternoon. I can use a humidifier in the fall and winter if it help; I am not expecting fruit that I can eat. There is a balcony with beautiful flowers
Will it be possible to plant some orange and lime seeds?
You definitely can plant seeds from an orange or lime however you should not expect to get fruit similar to the parent fruit. They will grow into small trees over many years (10 or more) and if they get enough light in the summer may even bloom. Start seeds in a small pot in damp potting soil. Make sure the soil doesn’t dry out or become too water logged while waiting for germination. As your tree grows you can transplant it gradually into larger pots, one pot size larger each time. Citrus is susceptible to scale and spider mites in indoor conditions especially during the winter so monitor your plant carefully. During the winter anything you can do to increase the humidity will help the plant to be healthier. The easiest and most effective way to increase humidity around a plant is to set it on a tray that is filled with pebbles. Pour water into the tray so that it is below the level of the bottom of the pot. The water will evaporate and increase the humidity in the area as it does so. You will find that it is often necessary to refill the water on a daily basis. In the summer if possible take it outside but introduce it slowly to full sun or the leaves will sunburn. In the fall as the days get cooler and before the first frost, bring your plant back indoors.