Master Gardeners, George Hibbard and John Hensley have been working along with the garden staff all winter. They say, visitors stop to ask every day “What’s going on?”   The short answer is succulents.

Next summer the Pincushion Garden, consisting of twenty beds (five and ten feet in diameter) that line the east walk between the Museum building and Piper Observatory, will be planted with all succulents.

“Why are we changing the design?”; to be historically accurate.  Henry Shaw and his successors used succulents and various cacti plants in almost all of the formal designs of the Italian Garden and beds that lined the entrance to the Garden.  We are trying to recreate a more historically accurate planting in the Victorian District to reflect the tastes and plant choices of that time.

Succulents require very controlled watering and good drainage.  This was not the environment for the existing pincushions, which were watered with the same pop-up sprinklers that irrigated the surrounding turf and which did not drain well due to the surrounding clay.  So the irrigation for the turf has been replaced with drip irrigation lines buried six inches below the surface on eighteen inch spacing.  The water will wick up to the turf, conserving water by placing it directly at the root zone of the plants and eliminating water evaporation.  Each pincushion will then have its own drip irrigation system.  So the only overhead watering will come from Mother Nature.

In addition, all of the beds have been dug out to a depth of roughly two feet.  Then multiple nine inch diameter holes have been bored down an additional six to ten feet through the clay in each bed.  Vertical drainpipes have then been inserted in each hole to further improve drainage.  This all sounds simpler than it was.  We encountered old sewer pipes, wiring, water lines, old crushed limestone paths and even coal.  In places, even six foot holes did not penetrate the clay pan.  And, by the way, hitting a working water line creates a great geyser.

We have now filled the beds with eighteen inches of slag gravel and covered that with garden landscape cloth to prevent the growing media from filtering down through the gravel layer.   (Slag is a byproduct of the metal making industry.  The reason we chose this material is because it is made locally so we are not only reducing the carbon footprint by obtaining it locally, but we are also recycling a waste product from the medal making industry.  It will provide just as good of drainage as if we were to purchase in another source of rock material).  Then this spring the beds will receive a six inch layer of the planting medium – a combination of sand and crushed  gravel.  Tests are currently on-going in the greenhouse to determine the optimum ratio of sand and gravel.  Finally, in June the succulent designs will be planted.  Jennifer Kleeschulte, horticulturist for the Victorian District, has ordered 33, 000 succulent plugs to be planted - WOW!

This is all a grand gardening experiment, and to our knowledge will be the largest of its kind in the world!   Many of the techniques being used are new to the Missouri Botanical Garden.  Let’s hope it all works.  It should be spectacular.

Article submitted by fellow MG George Hibbard.  Stop by the site during your vists to the garden this winter for a visit and a sneak peek at the new succulent beds.