That seemed like the ultimate deprivation of liberty.
To walk on grass is to belong on this earth. To live for years on and in concrete, with even struggling weeds punished for existing, is to deny connection to the world, and no matter how recalcitrant a criminal may be, it's a kind of death sentence nobody deserves.
We haven't gone as far as America, with its prison TV programmes boasting of its own cruelty, but we have nothing to rave about in our penal policy, which is hardly a raving success.
Maybe the bureaucrats involved were so truly ignorant that they had never heard of Quakers.
That would be bad enough, since they were the first religious group to care about what happened in jails, and famously try to do something about it.
They had experience of jails because they were a persecuted group in Britain, and later America, and spent time there.
Breaking away from the state religion, Anglicanism, they were punished for their beliefs like criminals in a time when beliefs mattered.
I got to know Quakers, or the Religious Society of Friends, when I was a teenager involved in the peace movement, where they were prominent.
Nothing in their beliefs seems offensive to me, but because of their pacifism they have been jailed here as conscientious objectors, which is why the flower-giving tradition began, after World War I.
The shocking conditions in jails bothered them from early on so much that they took up prison reform as one of their good works, along with the abolition of slavery.
Elizabeth Fry, an early Quaker reformer, has featured on the British £5 note. Such is the irony of history.
I would say Quakers, like flowers, are the very definition of harmless, and at the last Census there weren't enough of them to fill the average high school, which suggests they may fade away altogether in time.
The odds that they could be in cahoots with drug dealers? Millions to one.
They believe in kindness, even towards criminals. And in their actions - making hundreds of posies, for goodness sake! - they model their belief.
Whether the prisoners eat the flowers, whether they smash them on the floors of their cells, whether they are furious at being taken for sissies, I don't care.
But what they experience with these gifts is kindness, and they may register that.
There isn't enough kindness in this world, and wherever it exists we should celebrate it, not try to shut it down.
We are worried about the effect of deprived and neglectful childhood, in which poverty plays a large part.
The Dunedin Longitudinal Study has identified that future criminality can be predicted even in small children because of the harsh lessons of their everyday lives.
While we focus on children, they are members of families that are foundering, and in which parents are likely to be jailed.
If we are going to hold people to account by depriving them of freedom we have an obligation, surely, to expose them to decency rather than condemn them to more deprivation, which is what got them there in the first place.
Sound drippy and a bit Christian? Well it's the way I was brought up, and it has some relevance at this time of year, as expressed, unexpectedly, by Prince Harry, quoted this week as saying: "Just do good. Why wouldn't you?"
- Rosemary McLeod is a journalist and author.