Time to plant your balcony garden
Soil for container plants is easy to find. Don’t use “Top Soil”. It is likely to be mostly clay and too heavy for your balcony use. Potting soil (with or without time release fertilizer) will be just fine.
If you buy plants – fit them tightly into the pot. You will have a nice showy pot and it is unlikely that they will outgrow the space over the summer. If you plant seeds, don’t put the pot in full sun. Keep seeds moist until they germinate by covering the pot with plastic wrap to keep the soil from drying out and
How much sun your balcony gets will determine your choice of plants. Don’t forget reflected light from nearby buildings. Your balcony may receive direct sun only in the morning, but also receive reflected light from the building next door in late afternoon. This article lists 5 ways to categorize sun and shade for choosing plants (about 2/3 down into this article is the list). More information is there is you want the details.
Vegetables: most container vegetables like full sun but may need shade from reflected afternoon light or direct afternoon sun. Vegetables need to be checked every day to see if they need water – many will, especially when putting on fruit. Recommended Container Vegetables are listed by type and by name.
Herbs: Basil is a standard and will probably need water daily in hot weather. Try cilantro or a chocolate mint plant. Most perennial herbs grow well in containers and may survive the winter. Good choices are French Tarragon, any of the Thyme varieties, Winter Savory, Chives. Here is more information about Growing Herbs in Containers.
Flowers: If you would like to screen the view from your balcony – plant tall annuals. An 8 inch deep pot is best. All of these grow easily from seed: sunflowers, cosmos, morning-glory (add a trellis for it to climb). Amaranth is a grain ( not very edible) and grows 6 feet tall! Look for the burgundy variety.