Home > Begonian > Volume 67 (July/August 2000, pages 136 - 138)

Lathehouses for Every Climate
by Wallace W. Wagner

The first thing one thinks of when you mention "lathehouse" is a shade structure for use in hot, sunny areas like California and the deep South where the sun is too hot, the winds too strong, or the rain too intense.

The truth is that a lathehouse can be useful in any part of the country. Rather than just a shade accommodation, a lathehouse primarily modifies the atmosphere, making the sun less strong, rain soft, and the wind a breeze. Lathehouses should properly be called "filterhouses."

We are constantly told that certain plants require "modified sunshine," "halfshade," "a sheltered position", etc. Then we are asked to find a location in our garden that meets those conditions, often without success. It is hardly surprising that most of our gardens consist of only those plants that will grow any place. What a shame that we miss out on some prize specimens because we cannot meet, the plant's needs.

An often quoted objection to a lathehouse is that they are so ugly. And so they can be, if not designed properly. Lathehouses can be attractive to the eye as well as functional; a place to raise superb specimens of your favorite plants and a place to relax and enjoy the filtering affects on your mind and body as well as the well-being of your plants.

Designing the Structure

Structurally, the lathehouse roof should be flat and covered with the ordinary lathe (1/2" by 1 1/4") spaced the width of a lathe apart, with the lathe running north and south. The lathe should be supported at two-foot intervals to prevent sagging. Galvanized nails or screws should be used throughout. The framework for a sturdy roof should have 6" by 6" posts with 1" by 6" stringers between posts. Cross stringers can be 1" by 6".

The posts should be placed in cement to several inches above the soft level to prevent rot. Posts should be set at least one foot into the soil.

If you are growing a variety of plants from low growing to small trees or shrubs, then the roof needs to be divided into several elevations (photo opposite). Low growing plants wouldn't do their best under a high roof and conversely, tall plants wouldn't do well under a low roof. The elevation changes should be in increments of 18 inches, leaving the space open between elevations. Good elevations would be 8, 9 1/2, 11, and 12 1/2 feet.

Redwood posts will last the longest, but other treated wood will do. Make sure the chemical used in the treatment is not toxic to the plants (or to you). Some plants are very sensitive to preservatives.

If you have no choice of how to orient the lathehouse then that will dictate the design. The ideal in a moderate climate would be to have an open front on the north side. If you get cold weather from the north, then you would want that side to be a solid wall. You may want to insulate the coldest side with Styrofoam panel painted to match the wood. All sides should be solid from the base up to three feet.

For maximum protection you can close in all sides and use doors for entry. All sides except the solid side should be lathe laid in a square or diamond pattern. Use your decorating sense to design an attractive pattern. Many lumberyards sell prefabricated 4' by 8' panels of lathe in various designs. These can be used on the sides, but not on the roof. A leaded-glass window in the east and west sides would be the crowning touch.

Designing the Interior

When designing the interior of the lathehouse you may want to consider allowing room for propagating, storage of materials, such as soil, pots, stakes, tools, etc. You may also want areas to use for outdoor furniture for relaxing among your plants in the filtered climate.

Several rules will make the lathehouse more enjoyable and useful:

1. Make a path through the structure that allows viewing of all plants at their optimal viewing elevation.
2. Have varying levels of soil using mounds and depressions. Make sure you don't pile soil against the wood portions of the structure.
3. Plan your plantings before starting and don't crowd them.

The best method for raising beds is to use retaining walls of rock with the intervening space filled with moss and soil, puddled together (NO CEMENT) as a good drainage. Use natural stone; not cement blocks for best appearance. If you plan to grow maidenhair ferns, plant them against irregular chunks of cement. They like the lime.

Watering Facilities

Put in enough water lines (underground in cold climates) to be able to reach anyplace in the lathehouse with a 25 foot hose. If you have hot summers you may want to install a misting system about a foot below the roof to keep the air cool and humid. Make sure the jets are on the bottoms of the pipes so the pipes drain. otherwise the water in the pipes will become scalding hot in summer and freeze in the winter.

The Soil

For most plants you will not want to fill your raised beds with regular soil. Make your own soil from materials available in your area and customize it to the type of plants you will be growing in each area. Basically, use the same type of soil you have successfully used in your pot mix for the particular plant. If you are going to leave the plants outdoors all year and you have a long rainy season, you probably will not want to use time-released fertilizer since it will continue to release fertilizer even when the plant is not growing. That can harm the plant. If some plants will need to be moved indoors for the winter, sink the pots into the soil, rather than plant them directly in the soil. Then you can easily move the pots indoors in the winter.

Acknowledgement

In the photo above, you can see that the lathehouse is a model whose size you can judge from the flower bed in the background. The side view on the right highlights the three levels of the roof.  Wouldn't we all love to have a structure like this to protect our precious begonias?