The English-Gardener

CONSERVATORY VS GREENHOUSE
By Peter BonSey

What is the difference between a greenhouse and a conservatory? This question features heavily when you are deciding to build either of them onto your home. Both of these feature a construction that allows lots of natural light and ventilation. A greenhouse is predominately for the growing of plants and flowers outside of their season. It is a functional, utilitarian style of structure where appearance is not as important of a concern. The ability to wash down the floors after working with soil and carrying out other messy activities is very important. For the avid gardener or hobbyist the greenhouse offers much excitement, relaxation and at relatively low cost.

The conservatory, on the other hand, is more of a room, usually built right onto the side of the home. Its elements of design are more pleasing to the eye, and this is important as the area is often used for relaxation. Although growing takes place in the conservatory, it is only one of the functions. The use of large plants and flowers out of season to create a soothing living space for eating, reading or generally relaxing is the bigger part of the focus. It utilises all the elements of the greenhouse for light, ventilation and heating, but with the added perspective of bringing the outside in with the use of large windows. A stocked fishpond with a waterfall adds even more to the natural feeling of the room. The finish trim of the conservatory is less functional and more in keeping with the interior of a home.

In both structures the suggested lowest temperature is 60 degrees in the winter and a high of 70-75 degrees. This is sufficient to maintain many tropical plants such as Bougainvillaea, urn plants and Passion vine, as well as to grow fuller, more vibrant houseplants.

When considering building, the exposure of your home is important. Neither a greenhouse nor conservatory wants to be in full sun all day or in full shade. A suitable setting is where a portion of the interior gets sun all day and the rest gets varying degrees of sun.

Heating is usually best and most cost effective through a simple, separate direct vent furnace. These can run anywhere from $400 to $800. Cooling is obtained by use of a fan placed at one end of the room pulling air out, thereby creating a draft of cooler air entering from the other end. This can also be achieved by the use of temperature activated roof vents.

Roof blinds can be used for the reduction of glare and create shade during the hottest months. Lighting should always be subtle-flooding rather than harsh spots. Strip lights on the backsides of ceiling beams offer a hidden location with the ability to move the lights in the dark of winter onto your plants that need it most.

The best floors are made of Unilock, or terra-cotta tiles, as they act like solar collectors during the heat of the day and create less dramatic night temperature changes as the heat radiates out of these materials. Terra-cotta tiles should allow for moisture penetration. In mine I sealed the tiles but not the grout. This allows for any spilled water to seep away.

While I built mine primarily for the pursuit of my gardening interests, it has become a much-used family room. We meet here, talk, have breakfast, relax with our cats, and generally enjoy nature all year round. Our guests always want to sit in this area. I can fully recommend the use of either room to a family.

A greenhouse is supremely versatile. Not only can it save you money by allowing you to cultivate your own plants but it can also extend the scope of your gardening pleasure by providing a home for a collection of tender or exotic plants. With a greenhouse, you can raise a wide range of pants from seed or cuttings that will fill the garden with colour, texture and form at a lower cost than if your bought ready-grown plants from a garden centre. Raising your own plants is so much more satisfying, too. Fruit and vegetables can be grown and harvested earlier than if they had been grown in the open garden, and their growing season will also be extended, allowing you to enjoy home-grown produce for longer. Many tender plants will appreciate the protected environment of a greenhouse, as well, among them alpines, which hate damp conditions. Even if unheated, a greenhouse makes a useful asset, but by heating all or part of it you can increase its usefulness. By controlling the temperature, you can create the ideal environment for raising seedlings and cuttings to provide plenty of bedding and hardy plants to fill the garden. A heating system will also allow you to use the greenhouse for growing exotic plants, such as orchids, which need constant temperature, bright light and high humidity. The latter should be on the side of the greenhouse that gets the most sun so that they won’t be shaded by the staging. The staging itself must be strongly constructed, when loaded with pots and trays; it will have to support a considerable amount of weight. There’s a variety of ready-made staging available, or you can make your own. A slatted top will allow air to circulate around your plants, but in winter it won’t provide any protection against the cold. In this respect, a solid top is better. If it has a shallow lip around it, so much the better, as you can fill it with sand or gravel, keeping this moist to provide the plants with a damp atmosphere. Alternatively, you can place a layer of capillary matting on it to provide the plants with moisture. For winter protection, a deep boxy top can be filled with sand and the plant pots plunged into this up to their rims. This will not only keep them moist but also warm.

Floor beds are an ideal place for growing tall plants such as tomatoes. Dig them in the winter the same way that you would outside. However, after a year or two, the soil will become exhausted and will need replacing with fresh soil from the garden. You may find it more convenient to use grow-bags which if you do use, take care not to allow them to dry out, as the compost used is very difficult to re-wet. At the same time, make sure you don’t over-water them, which will also cause problems. Punch holes in the lower portion of the bags to aid drainage. Grow bags are inexpensive and can be discarded after a season’s use.

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