However, the term reminded me of a memorable interaction I had many decades ago with an old woman who wanted to write a program in x86 Asm to manage various aspects of the plants in her garden. (She did succeed at doing so.)
A powerful editor/IDE makes it ... not the worst programming experience in the world.
And since it's "so detailed" it's pretty easy to understand and explain, unlike higher-level languages that "do everything for you".
"Home-cooked apps" is still my preferred phrase. Personal software and subsistence development are also good terms.
"Utilities" doesn't indicate the audience or the intended longevity of use of the tool like "houseplant" and "bouquet" do.
Both indicate they are built for personal use cases, suggesting potentially low reusability. The longevity of "houseplant" suggests it's intended for ongoing use, while "bouquet" suggests a limited use tool.
With work, either could be made reusable for others, but I think it's implied that the scope is an edge case or uncommon case that likely only applies to its creator or a very limited audience.
I see value in the terms, but these terms may themselves be houseplant terms, not sure if general adoption is useful to someone not building houseplant software, they are mostly hobbiest terms by definition.