Planting a Trough Garden

Have you ever thought of creating a tiny little garden in a trough? It is rather like having a little miniature garden, composed of special, fun little plants. Alpine trough gardening is very trendy, and what usually comes to mind when you picture a trough garden. But you don’t need to limit yourself to alpines. Annuals, herbs, hostas, moss, ferns, and even smaller or dwarf perennials can be used. Last summer, we were fortunate to have David Culp provide trough planting demonstrations at Thyme on the Terrace. Below, we provide some of the key principles he shared with us, as well as adding in a few of our own thoughts.

Before you can plan your garden, you need to select a trough. You can make your own, or buy a new or old one. Hypertufa, and aged or carved stone are all options. You can also use old ceramic or carved stone sinks. The cost of a trough depends on the material. Obviously, the old stone troughs and sinks will be the most expensive because they were hand carved in the 18th and 19th century. Prices will typically begin at $125 and go up depending on the size. However, hypertufa and aged stone offer less expensive alternatives to “the real thing.” You should be able to find a good small starter trough for under $100.

Once you have selected your trough, David tells us that if there is one word to remember in planting a trough or sink, it is drainage. Make sure you have an appropriate number of holes in the trough and use a quality soil mix that has good drainage. Start with a sterile soil mixture, rather than your own garden soil (which has bacteria in it and will give alpines a hard time in getting started). Mix in Gran-I-Grit with the soil. If you are planting a trough, a 50/50 ratio of grit to a good potting mix is the minimum. This can be raised to as high as an 80/20 ratio depending on whether you are in a sunny location, have plants that require more drainage or are planting a strict alpine trough. Before putting the soil mixture in the trough, cover each hole with a piece of plastic screen. This prevents pests from getting in, while still allowing for drainage.

When planting the trough, David suggests finding some fun stones that work well with the size of the trough and setting those in the dirt first. Choose the stones that compliment the coloring of your trough and set them on an angle with the sides of the trough.

Now you will need to choose your plants. David suggests including three different textures, and aiming for 12 months of interest. Of course, the type of trough and location will drive what plant options you have. While you can put perennials and annuals in your troughs, you should ensure that the trough is of big enough to accommodate your selection. A larger trough is necessary for most perennials to protect them from winter damage. We recommend that you choose perennials or plants that are 1 zone colder than the zone you are in to give them the best chance of survival in the colder months.

Below is a link that provide either plants for troughs or additional information on plant selection for troughs.

http://www.arrowhead-alpines.com/

Plant the plants high so that they have adequate drainage and oxygen, and don’t pack them in. Repetition of some of the plants, emulating a natural drifting, is a way to make the trough look more of natural.

Once the plants have been placed, finish off your trough by covering the exposed soil with aquarium gravel or pea gravel. This keeps the soil from washing out. Keep organic matter away from the crown of the plant . We’ve also used moss as a cover for our shade troughs which provides a charming addition and gives winter interest. Ensure that the trough is raised up slightly on stones or bricks to provide adequate drainage. Water frequently until the plants are established, then sit back and enjoy!