Les Serres de la Ville de Tours

The Association de Botanique et Mycologie de Sainte Maure de Touraine was lucky enough to get access to the greenhouses which produce the plants used by the City of Tours for its many magnificent floral displays. A dozen or so of us were met at the entrance to the Bois des Hâtes in Chambray-lès-Tours, where the greenhouses (les serres in French) are hidden away. In total, they produce, from seed, 450 000 plants a year as well as nursing the previous year's perennials and overwintering some of the topiaries and standards (many of which are very old – at least 50 years).

Our first sight of the greenhouses, which along with the outdoor holding facility here, cover 4 ha.

 Sylvie (below left), the gardener who gave us a guided tour, with Maurice, who organised the visit from our end. The yellow and blue sheets hanging from the rafters are biocontrol sticky plastic traps. Yellow is for whiteflies, aphids, leafminers, thrips and fungus gnats, blue is just for the last two. The density here suggests they are using them for monitoring and light control. Sylvie gave several incredibly adept demonstrations of how to prick out tiny seedlings with barely two leaves, using only her biro to both extract the plant and make a new hole for it, never touching the stem or roots of the seedling. She was an absolute fountain of information about how the greenhouses are managed, and sometimes I got lost when I missed a word or two, then wasn't able to make up the ground to understand the gist. The work is extremely physical, with the plants being manhandled many times during their lifespan. Some planting of fine seed is mechanised and parts of other processes, but mostly it is gardener muscle power, seven days a week. One gardener comes in on the weekend and waters everything on their own.

More biocontrol -- this time a card which has the remains of parasitised whitefly pupae stuck to it. These cards, with the unhatched parasitised pupae, are introduced to the greenhouse so that the parasitoid wasp Encarsia formosa hatches into the greenhouse and controls the resident whitefly by parasitising them in turn.

I really struggled to decide which photo of lovely foliage to put on the blog. In the end I chose this interesting copper and raspberry coloured plant, but can't tell you what it is now.

Filling the cell trays with potting mix was a real production line. The potting mix was a combination of peat and coir, sometimes with vermiculite added.

The endless task of potting on. The gardener engaged in this task said he loved it and could do it all day. To push the plugs out of their tiny cells they have a spike board. The tray is pushed onto the spike board, and up pop the plugs, ready to be plucked by the leaves and plonked in the perfectly sized hole created by the custom made dibber.

Espaliered hornbeam trees, heeled in to a pile of soil and leaf litter, awaiting their spot in this year's public display.

As always with places like this I was momentarily startled by the quantity of plants that to me are noxious weeds and alien invaders, but to Europeans are beloved and pretty garden plants (I'm thinking of lantana and asparagus fern, for example). Other plants being carefully nurtured in the pseudo-tropical conditions of the greenhouse over winter to burst out into colour in the summer are the sort of thing I had providing shade along the front of the verandah in Australia, planted in the ground and out in all weathers (bougainvillea). Some plants, which I have seen in public planting displays and admired, but never been able to identify have now been revealed as things like sweet potato and streptocarpus. That was a surprise -- I would have thought both much to tender to put outside even in the summer here.

Ultimately, the most useful thing I got out of the visit was an addition to my vocab. I learnt that un massif  (des fleurs) is a flowerbed. I'd been wondering what the word for flowerbed was, but never got round to asking. There was so much use of this word during the afternoon of our visit that I eventually twigged!

This blog post is going to form the basis of the outing report in the botany club newsletter. Jeannine, the secretary, spotted me taking notes and gleefully pounced on a 'new victim' (her words) suggesting I contribute to the newsletter. Either she will translate what I've written into French, or I will give it a go.