Plant A Trough Garden
Rock garden enthusiasts grow smaller plants in hypertufa troughs, creating miniature landscapes. Hypertufa troughs are created by mixing cement with perlite and peat, pressing the mixture into a mold, and allowing it to dry. The result is a strong, light growing container reminiscent of the animal watering troughs used as planting containers in the British Isles.We have also had good results using other types of containers to create these mixed alpine plantings.
Although not difficult, there are a few things to keep in mind when planting a trough garden.
Over time, moss grows on the rough exterior of the hypertufa trough which gives it an aged, hewn rock appearance. This rustic appearance is part of the charm of this type of container. Troughs, as with all containers, will last longer if put under an eave, in a cool greenhouse or otherwise protected from freeze/thaw cycles in cold weather climates.
Although hypertufa is a porous material which helps keep the potting soil from becoming too sodden, it is important to make certain your container has excellent drainage. Drainage holes can be created when the trough is being made or added later, as in this case. We used a large masonry drill bit to create holes at intervals along the entire bottom of the trough.
I selected a variety of small scale native succulents for this fairly shallow trough and planted them high in a gritty mix of potting soil amended with extra crushed rock. I mixed in a small amount of time release fertilizer and will apply diluted liquid fertilizer later only if plants appear stressed.
Rock accents were added after I was satisfied with plant placement. Rock accents could have been positioned before I planted but I prefer to plant first in most containers.
Crushed rock, in this case quartzite, was used as a mulch topdress, leaving a depressed lip around the inside edge of the planter to facilitate watering. We use a gentle sprayer and make multiple passes over the trough until water comes out the drain holes. An advantage of using a small container is that it easy to submerge in a basin for occaisional thorough watering and application of liquid fertilizer.
Finally, I made a label "map" of the plantings to help with later identification of Dudley calcicola, Calyptridium umbellatum, Sedum laxum ssp heckneri, Lewisia sp, Talinum okanogense.
A Few Other Trough Garden Examples
New Zealand Plants Scleranthus uniflorus and Leucogenes grandiceps .
Campanula bellidifolia in trough
Pink flowering Juniper Leaf Thyme (Thymus neiceffi) and white flowering Greek Yarrow (Achillea ageratifolia) made an attractive flowering combination.
Individual troughs can be grouped together to create a trough garden. Dwarf conifers are often used and usually grow very slowly in the low fertility soil and confined root run of troughs.
Troughs can be grouped with other containers in a mixed grouping to form a trough garden.