Ever fall in love with a trough, but wondered where to place it? Or, ever fall in love with a few too many plants to fit in your trough? I often work with people who wistfully explore the alpine benches but have no rock garden, or who might be ready to make a small commitment to doing a little rock gardening but aren't ready to jump headlong into building a scree, raised bed, or crevice garden. Believe it or not, there is another very appealing way to go. It has to do with combining your troughs with a small planted rock garden area. The containers supply some "hardscape" helping to anchor and balance the space, and the alpine planting designed around it decorates and enhances the troughs. Yes, you will still have to offer sharp drainage, gravel mulch and (usually) full sun, but we are only talking about a space about as big as your vestibule -- or a parking space for an average car.

Selecting the site will be critical for esthetic reasons as well as the cultural contentment of your plants. Choose somewhere you can view the containers up close. This is jewel box gardening - small treasures are lost at a distance. This is also the kind of planting friendly to manmade elements; your collection can be backed up against existing walls or settled at the side of some steps. Probably the best examples of this sort of arrangement I've seen occur on patios, although not the poured concrete kind, as that would involve a jackhammer. But if you have fieldstone, flagstone, bluestone, or brick, you are in luck. Any terrace that will allow you to remove a few pavers will work. Obviously you must take a few practical things into consideration:

• Don't locate your project directly under the downspout from the roof gutter which will flood your plants.     
• Don't locate your project under an overhang unless you are willing to be the only source of water your plants have to depend on.
• Design it out of the way of your favorite outdoor furniture area, grill, or serving area.
• Be thoughtful about traffic patterns. Will kids or dogs tear right through or over it? If so, pick a different spot. Will you become annoyed walking around it? Generally speaking, most patios have a quiet zone, even a dead space. Sometimes these are backed up by a retaining wall, a nice addition.

Make a selection of from two to five troughs. Two can work with the addition of a large architectural stone on the ground designed into the mix, or even a dwarf shrub. (Don't try to use four unless you are a master at this)! To avoid an out-of-scale look make at least one trough fairly sizable and in a classic rectangular shape. Then play with sizes and shapes that please your eye. A tall cylinder, a squat square and a big rectangle work beautifully together. But there are no absolutes in designing as everyone's space and taste are unique. A cluster of only cylinders, some taller or raised up can be pleasing, too. A bowl, an urn or a daring "free-form" can lend an unexpected note. By the way, do your trough shuffling while they are empty and save the wear and tear on your back. Plus, it's a sure bet that the way you end up arranging them will influence the way you plant them up.

So you have found your perfect corner and arranged your troughs pleasingly. Remember to consider elevating one if it will make for a more interesting profile. A couple of bricks will do the trick for a small trough, as many as eight or ten for a substantial one. Make sure that none of these bricks block the drainage holes. (This is another good argument for arranging them empty).

Illustration by Lori Chips

  

Okay, so far all of this sounds like a normal day in a trough gardener's life. The next step is the fun one. Remove some of your paving stones immediately around the base of the troughs. Each situation is different, so use your eyes and your sense of balance and proportion. How many and where to remove them is a personal choice. Perhaps open up a good sized flag stone behind and to the side of the collection to plant a small columnar conifer. Or, maybe a space on the other side for a dwarf fragrant Daphne. If there is no wall behind the grouping a few judiciously selected large rocks could be incorporated there. If that is to work, the rocks must be large enough to look grounded and in scale with the containers. The rocks should be of a color and tone that will not fight with your troughs, your paving, or the nearby landscape. I have never seen blindingly white quartz work in a New England setting.

 

Next, remove bricks or stones on the sides and front of the troughs with an eye to planting tiny alpines and little spreaders. Where alpines are to grow you will need to dig out and replace the soil with a mixture composed of at least half gravel. And since no one will be scraping a chair over their crowns, you can indulge in all the charming buns and cushions you may have been eyeing all this time. Try a gentian, a couple of dwarf iris, one of the easier androsaces -- even a lewisia on the north side of a trough. By its very nature the ground below the troughs and below the pavers is ideally cool for the alpine roots, a situation that rock gardeners struggle to achieve.

 

It's easy to see how the troughs lend structure to the plot; the in-ground planting lends its ornamental element and a sense of abundance. Also, it gives the feeling that your collection has been there forever. Place a species at one corner inside your trough then another one or two of the same on the ground below. It will look as though the plants happily seeded in, which, by the way, will begin to happen over time and with certain subjects. Easy seeders include Arenaria, Draba, Chaenorrhinum, Erigeron, Erinus alpinus, and Aquilegia just to name a few. Decorate the base with a couple of big sumptuous Sempervivum, even inserting them into thyme or a different ground cover, like buttons on an upholstered cushion.   

 

Compared to a large landscape renovation, or putting up a gazebo, this may seem like small potatoes. But as small as these elements are, their effect can be big. Even a non-gardener's eye is drawn to a collection like this. Miniatures have a magic that people want to get closer to. So mix up a batch of appletinis on your patio and watch how your new corner becomes the hot topic of conversation.