Val-de-Marne: thousands of plants at the Grand Paris Horticultural Center’s free Open House days

You’re the kind of person who, with the first sunny days, wants to get your hands in the soil? The Centre Horticole de Grand Paris Sud Est Avenir, based in Mandres-les-Roses (Val-de-Marne, 94), opens its doors for free on Saturday, April 18 2026, from 10 a.m. to 6 p.m. A rare chance to step onto a production site usually closed to the public, and to stroll among thousands of plants and flowers destined to brighten the public spaces of the territory.

This center offers an educational program open to everyone: the Garden of the Five Senses, a variety of vegetable plots, a beekeeping area, a picnic space… Plenty of space to explore freely or on a guided tour that day. The 13,300 m² of greenhouses at the Roseval estate form a large-scale plant production operation, entirely managed by a team of professionals dedicated to greening the surrounding municipalities.

Throughout the day, visitors will be able to enjoy the following:

• Guided or self-guided tour of the site
• Workshops open to all (repotting, composting, floral arrangements, integrated pest management, …)
• Plant swap with the Graine de Jardinier association
• Introduction to beekeeping and sale of honey from local hives
• Games and exhibitions on biodiversity
• Stand for the new Mandres media library (on-site sign-ups and book borrowing)
• Food area with a food truck and a treats stall

One of the day’s standout moments will undoubtedly be the plant swap, held in partnership with the Graine de Jardinier association, founded in 2004 in Saint-Maur-des-Fossés, whose mission is to promote gardening to the general public through environmentally mindful practices and a spirit of sharing. If you have cuttings, seedlings, or plants to part with, now is the time to tuck them into a bag before you head out.

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Urban beekeeping enthusiasts won’t be left out, as a tour of the center’s hives is planned, with honey tastings and local honey for sale. A fitting tribute to the richness of Francilien green spaces, the garden center sits along the Végétale, this green corridor that cuts through eight Val-de-Marne communes along the old Paris-Bastille railway line, once used to ship roses into the capital. The site’s history is truly enough to spark the imagination.

Families with kids will also be there: biodiversity-themed games, nature workshops suitable for even the youngest explorers, and food trucks to recharge between repotting sessions. Entry is free and no booking is required. The Grand Paris Sud Est Avenir Horticultural Center is located at 12 rue Auguste Dupin in Mandres-les-Roses, and is notably accessible via Paris Metro Line 8 (Pointe du Lac station) followed by local bus connections.

Our take: a lovely spring outing for nature lovers, weekend gardeners, families seeking a green detour away from the usual tourist trails. We especially appreciate its educational angle and the way this production site, little known to the general public, opens up for a day.

This is aimed at families, seasoned or budding gardeners, biodiversity buffs—in short, anyone looking for a free spring activity in Île-de-France.

To discover in the same spirit:

• La Ferme de Gally, in Saint-Cyr-l'École (78), known for its gardening workshops and family fruit-picking sessions
• Esprit Jardin, the plant fair with free entry at Versailles as well.