Growing Tomatoes Anytime in the Greenhouse

Most gardeners will tell you that few things can beat the outstanding, fresh taste of home-grown tomatoes in the summer. Luckily, with a greenhouse you are not limited to the summer months; you can grow delicious tomatoes whenever you want. Tomatoes can be picky plants, but with a little bit of practice anyone should be able to produce their own supply of these mouth-watering delights year-round.

Starting Out

In order to grow the best tomatoes possible, it is important that you give your plants a healthy start. Begin by purchasing seeds developed especially for greenhouse use (readily available in seed catalogs,) which will help you to avoid some common greenhouse problems. Start the seeds in warm conditions, preferably under grow lights and on heat mats, and allow them to develop for a couple weeks before transplanting. Eventually, you'll want the plants to be in very large containers (at least ten gallons in size) so that they will have adequate room to grow. Be sure that any containers you use have been sanitized with a mild bleach solution to prevent the spread of disease. Also, use fresh soil instead of last year's, which could possibly pass diseases to your plants. One common problem with greenhouse tomatoes is Blossom End-Rot, a condition that is caused by a calcium deficiency. To compensate for this, be sure to add an additional calcium source to your soil such as bone meal.

Choosing a Location

Tomatoes should only be placed in a greenhouse that is already healthy. If you notice any pre-existing problems with disease or pests, treat these problems before exposing your tomato plants to them. Tomatoes are prone to bugs such as white fly, which can ultimately lead to their detriment. You can minimize these problems by simultaneously planting herbs such as basil and lavender in the greenhouse that will help to deter these pests. Be sure that your tomato plants are placed in a sunny spot that will be near a heat source during cold weather.

Lighting

Often times the reason that tomatoes will not grow during the winter is that they do not have enough natural light. Because of this, supplemental lighting is almost always required throughout winter months. High-pressure sodium lights should be used for tomatoes because they encourage flowering and fruiting. For best results with tomatoes, lights should be used up to 16-18 hours per day. Make sure to use a light with the proper wattage for the area you wish to use it in.

Heating

If the proper temperature is not maintained within the greenhouse, the tomatoes will fail to produce. You should plan on keeping the greenhouse above 60°F, but below 90°F. In most areas, this will require some heating during cold weather. It is important to get a heater that puts out the proper amount of BTUs for your greenhouse so that the temperature will stay in the proper range. You can use our online heater calculator to find a heater that will suit your needs.

Additional Resources
Solexx Greenhouses - perfect diffuse light for growing tomatoes
Greenhouse Heaters - An assortment of heaters for the greenhouse