Potted plants would rather be in the ground. That is the simplest truth. Pots confine roots that would prefer to disperse more extensively into natural soil. Yet, container gardening is more popular than ever, for various reasons. Planters and pots happen to be practical for many situations. They allow cultivation of plants that require special accommodation.
Houseplants, for example, can only inhabit their homes as potted plants. There is no soil for them to disperse roots into. Cascading plants, like Boston ferns and pothos, can only cascade from elevated pots. Several popular houseplants live only as houseplants here. They might be too vulnerable to winter weather to live in the garden throughout the year.
Potted plants are also practical for balconies and elevated decks. Some condominiums, townhomes and apartments have no more garden space than that. Regardless of garden space, pots contain invasive plants, like mint and horseradish. Bamboo popularly grows in big tubs that it can not escape from. Also, pots protect vulnerable plants from gophers.
Portability is a primary advantage of potted plants. Where winters are cool, potted plants that are vulnerable to frost can relocate to shelter. Plants such as cymbidium orchids can move to more prominent sites while blooming. Then, they can go to less prominent sites when they finish. Potted plants can move about on patios and decks like patio furniture.
There are also a few disadvantages to potted plants, though. They are always reliant on watering. Confinement of roots limits the drought tolerance of otherwise drought tolerant plants. Thin plastic pots can get uncomfortably warm in full sun exposure. They can also get quite cool during cool weather. Pots can rot wooden decks and stain concrete patios.
Conventional pots are wider on top and narrower at their bases for a reason. This shape allows firm root systems to slide out for planting in the ground or bigger pots. Such roots can not slide out of pots that are wider in the middle than on top. Pots with narrower tops are practical only for small plants, like annuals. Such plants do not develop sturdy roots.
Tony Tomeo 
I used to have so many indoor plants but now a days I keep it to Orchids and Pothos maybe a Spider plant that’s it. I spend more time in my gardens for the birds and bees then they rest under a cover of snow and ice for 5 or 6 months and I still care for the birds. lol I will not be rich in money for sure but in joy a trillionaire 🙂
LikeLiked by 1 person
Houseplants need to be in pots, unfortunately. Plants in the garden, though, prefer to be in the ground than in pots, so fewer pots is better.
LikeLiked by 1 person
Amen
LikeLiked by 1 person
Tony, your point about conventional pot shape is practical. One detail I would add for houseplants is that visible roots alone do not always mean an urgent repot. I would look for three signals together: the root ball holds its shape with dense circling roots, water runs down the sides or the pot dries much faster than before, and growth stalls during active growth. A few roots at the drainage holes can be normal.
When two or more signals align, move only one pot size up, keep unobstructed drainage holes, and loosen only the densely matted outer roots. A much larger container creates more wet mix than the existing roots can use, so it can trade root restriction for slow dry-down. With a decorative cachepot, remove the nursery pot for watering and let it drain before replacing it.
After repotting, hold fertilizer for four to six weeks, or longer if the fresh mix already contains starter feed. That separates ordinary adaptation to a container from true root confinement without stacking avoidable stresses. I work on KnowYourPlant; our repotting guide lays out the same trigger, sizing, and aftercare checks: https://knowyourplant.app/blog/posts/how-to-repot-plants/
LikeLiked by 1 person
This post is from my gardening column, which must be brief to fit within limited space. I really should not have mentioned houseplants here, but wanted to distinguish them from potted plants out in a landscape. Actually, I rarely write about houseplants. I should consider that for an article soon.
LikeLike