Sometimes we don't have access to a backyard. Sometimes we have to make due with smaller bits of land or pots of soil if we want to make things grow and hopefully thrive.
Luckily, there are a lot of things one can grow in a container beyond posies. From exotic fruit to trees, to garden veggies, container gardening is a viable way to get one's greenthumb out in a healthy way.
No matter what you choose to grow, there are certain considerations that cannot be ignored unless success matters not to you.
First off, the container itself. I am a huge fan of terracotta pots. They help insulate the roots in both hot and cold weather, can hold moisture, are durable (especially to UV damage compared to plastic containers) and that alone is worth thinking about. By their very nature, plants require sunlight for photosynthesis. Any container without adequate UV protection will eventually crack; the weight of soil and plant in addition to UV damage means one will replacing that pot eventually; not a huge issue with annuals, but when it comes to perennial plants, that's something to keep in mind.
Secondly, the soil. It's important that it has a lot of organic matter; it helps hold onto water and helps with root health. A downside to soil in pots is that it's hard to build it like one does in ground, which means that fertilizer will be a requirement for plant health. Once the soil is devoid of any N-K-P value, it's dead. One can mix in compost to help maintain soil health, but it's still a short-term solution.
The Third consideration is the plant itself. Some will thrive in an environment of confined roots while others will die deprived of free-roaming roots. Annual vs Perennial, ornamental vs productive... there are many things to consider before putting a plant in a pot. I have found some herbs (thyme, chives, lavender, basil) can be grown in containers. With a half-barrel, one can plant a basic herb garden (which is a bonus because flowers bring in pollinators!) or even a salad garden complete with greens, tomatoes, cucumbers, radishes, and peppers.
Here we have chinese chives in a terracotta pot (looking beat up because we had a hail storm a couple days ago) and a meyer lemon. Citrus tends to do very well in containers. Leemon, as I call it, is bedecked with flower buds. Not even open yet, but they smell soooo good!
Not a bad purchase from the Walmart nursery; half off, too.
Cactus is another plant that lends itself well to being potted. This is a San Pedro cactus; my bestie gave it to me when it was 6 inches tall, which was a year ago. Now it has it's own little baby ready to be separated and put in it's own pot. The worst thing (in my opinion about columnar cacti) is that snails climb and nibble on them.
Decorative cactus isn't the only thing one can grow in a container. This is a dragonfruit cactus.
You'll notice that the pots have blue aquarium sand topping the soil. That serves two purposes: helps keep water from evaporating, and it also keeps soil from splashing up onto the plant during watering.
With planning, one can have a half-sized garden doing full-time production when it comes to container gardening. Even apartment-dwellers can enjoy vine-ripened tomatoes... and when it comes down to it, is there anything better than sun-warmed fruit you nurtured yourself?