I inherited some small/sickly shrubs from my parents when they moved to to a different city. I re-potted them into a bigger pot and it grew tenfold in a span of a few weeks and bloomed.
This, below, is a Crown of Thorns. Very hardy shrubs, they don’t care where you put them, how much sunshine they get or how frequently you water them.
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The best part is, you can cut off any of the branches and pot them and they grow into full-sized plants. Some of them are part of my plant wall (bottom row).
The flowers are in perpetual bloom all year round.
The 2 above are on different bathroom window sills.
These plants require absolutely no maintenance.
The first one is kept in partial shade, the other 2 get direct sunlight via windows 3-4 hours in the summers.
I water them once a week or less. Although they don’t require any fertiliser, I fertilise them every 2 months, which encourages leaf growth.
Here’re some good tools which will help you with your gardening.