What can be confirmed
Themi Living Garden exists and is mapped as a named place in Arusha, on the Themi river which runs down off Mount Meru through the eastern side of the city.
That is close to the limit of what can be confirmed. No Tanzanian government body publishes a description of it. Arusha City Council’s own tourism account names conference tourism, three heritage sites and the craft and gem trade, and does not mention it. It is not a national museum centre, a forest reserve or a protected area, and no managing authority for it appears in any government record consulted for this page.
Why the page exists anyway
The name circulates on itineraries and in city listings, which is exactly the situation this kind of page is for. A traveller who sees “Themi Living Garden” on a half-day plan should know that there is no authoritative description behind the name, no published opening arrangement, and nothing to tell them whether an hour there is a garden walk, a restaurant terrace or a private event space.
The Themi valley itself is real and is one of the few green corridors through the city, so a green space on it is entirely plausible. Plausible is not the same as documented, and this page does not fill the gap with invention.
What to do with that
Treat it as somewhere to ask about locally on the day rather than something to plan a morning around. Arusha’s dependable ways to spend a spare few hours are all documented: the markets, the two national museums, and the foothills of Meru. See the food and market tours guide, the museum tours guide and the day hiking guide, and the Arusha guide for how a spare day in the city is best shaped.
Common questions
Does Themi Living Garden exist?
It exists as a mapped named place in Arusha. What it offers a visitor is not described by any Tanzanian authority, so this page describes none of it.
Is it a public park?
Unknown. No government source names it, and no managing body for it is published. Ask locally before travelling across the city for it.