the greenhouse

 The Fruit Garden|  The Greenhouse | The British Connection| Meet the Herbalist
Workshop Brochure |The Herb Garden |  HOME | Garden Tour |  Links | Awards |

Extending the Season

Even a small greenhouse can produce an amazing amount of plants and in a short season region like Newfoundland, a greenhouse is an essential tool if you want to start from seed.   A 20' x 44' greenhouse is used to start the many herbs and plants that are used and sold on the farm.  A variety of seeds are started in the greenhouse by early March, some varieties before that.  Of course air heat at night and during cold, cloudy days is  essential for maximum growth.  Bottom heat in the form of heating cables will give gentle heat, providing roots and seedlings with a temperature of about 70F, even if air temperatures are cooler.  Warm roots make happy plants!

Space needs to be used wisely and  that means plenty of long benches and shelves, staggered to get the most out of the light.   Seed trays and young plants will need to be turned and take turns with their neighbours to ensure that growth is steady and consistent.  Sunlight even in April can turn the greenhouse into an oven, scorching young plants, so a single layer of Reemay (the lightweight garden cover) ican be used on the roof and southern facing sides of the greenhouse.  This is translucent enough let sufficient light through for effective growth, but also diffuses the light so that plants do not burn or bake.

Other methods of shading, such as economical bamboo or reed blinds on the roof of the greenhouse provide adequate shade on bright days.  For glass greenhouses, a weak solution of whitewash  paint can be used to cover the roof and south-facing walls to diffuse the light.

Watering at the seedling stage is critical and a spray or fog mist from a handheld hose or pump provides just the right amount of moisture without drowning the plants.  Seedlings are very susceptible to 'damping off' a disease that pinches the stem at soil level, killing the plant.  Air circulation will help prevent this problem and a fan which ensures sufficient air flow through the greenhouse will help.



The Coldframe

Once seedlings are big enough to handle, they must be carefully transplanted, usually into the pot that they will stay in until ready to plant out in the garden.  A small amount of fertilizer can be added to the water you use for these transplants to get them off to a good start.  Place them out of direct sunlight for a day or two to get over the shock of being transplanted and they should be off to a great start.

Plants that are in their rooting containers for more than a few weeks will need fertilizing at least once a week to ensure healthy growth.

A couple of weeks before plants are due to go into their permanent bed in the garden, they must be hardened off.  This process allows the plant time to adjust to a cooler temperature and it will be less likely to brown off or die when placed out permanently.  To harden off plants a coldframe is useful.  This is rather like a mini greenhouse, but will allow you to open it up completely on fine days exposing plants to wind and sun and showers.  If the weather is cold, the top can be kept closed, still affording the plants protection from the worst elements.  At first, plants should be brought back into the greenhouse at night when its coldest, but after a week or so of staying out all day, you can just close the cover at night .  When all danger of frost is over (usually around the first week of June here) you should be safe to place your plants in their permanent position.





Greenhouse plants

In Newfoundland, a greenhouse extends the growing season at both ends, spring and fall, and allows experimentation with a lot of non-traditional plants that need a more tropical setting - fruits, vegetables and herbs.  GGrapes, eggplant, garlic, hot and sweet peppers and the traditional tomatoes and cucumbers thrive in the moist, warm atmosphere of a greenhouse.  Careful attention to watering and feeding are essential, as well as watching for insect and disease pests, just as you would in a soil-based garden open to the elements. Natural, organic insect repellents and insecticides can be used and removal by hand of visible insect pects will keep crops healthy and chemical free.





This was the greenhouse in the winter of 2000-2001.  The record setting year for snow in Newfoundland and Labrador, with over 20 feet of snow over the season, breaking a 119 year old record!

Overwintering plants

in the greenhouse

The greenhouse provides some protection for plants during the winter months and can see some of the tender species through a winter that would surely kill them outside.

Tender flowering plants and tropical ones will NOT survive in an unheated greenhouse unless heat is provided, which is an expensive proposition in an area that requires heat for these plants from November to April.  These plants will only survive if brought indoor, placed in a bright sunny area and treated as houseplants for the winter. Peppers and herbs respond well to being brought inside for the winter and will reward you with crops in November.

Plants that have been successful overwintering in the greenhouse are rosemary, grapevines and slightly tender perennial flowering plants.  The temperature in the greenhouse, even on a cold day, if it is sunny will rise significantly and can dry out plants, so careful watering should be carried out if the plants seem to be wilting dramatically.  Plants during the winter can survive without water, but there will be leaf loss and some casualties, even if every precaution has been taken.

 The Fruit Garden|  The Greenhouse | The British Connection| Meet the Herbalist
Workshop Brochure |The Herb Garden |  HOME | Garden Tour |  Links | Awards |

   Updated October 26, 2002