How to Grow Hothouse Vegetables

Some gardening experts make no distinction between the terms "greenhouse" and "hothouse" while others do. Greenhouses are unheated structures used to get plants started early in a sheltered environment while hothouses use either artificial heat or a system which combines solar heating with ventilation to keep temperatures inside the structure constant. Knowing how to grow hothouse vegetables will give you a longer growing season and should be more productive than normal gardening.


  1. 1
    Make a mini-hothouse to get a head start on your garden. A small project can involve making a mini-hothouse using a plastic tub about 2 by 3 feet (61 by 91 cm) in size.
    • Clean the tub thoroughly and line the bottom of the tub with pebbles to keep water away from the potted plants you will place on top of the pebbles.
    • Fill pots with potting soil and add a few seeds. Sprinkle a little potting soil over the seeds and water lightly.
    • Place plastic wrap over the tub and put it into a sunny spot. Water periodically when the soil becomes dry, but take care not to over-water; just be sure the soil is kept moist.
    • Remove the wrap when the plants are 2 inches (5 cm) in height. Allow the plants to grow uncovered until the weather and conditions are right to transplant them into your regular garden.
  2. 2
    Decide on the materials and location for your larger hothouse.
    • Choose a spot that receives 6 to 8 hours of direct sunlight daily. Be sure you have easy access to water. Find a site protected against prevailing north winds.
    • Purchase a greenhouse or hothouse kit or build one yourself using a frame, glass, Plexiglas or plastic film. You can find plans online or in how-to magazines or books.
    • Determine the floor you want. It could be concrete, dirt or gravel, for example. Concrete or brick will help hold the heat, but could cause mold and bacteria to grow because they also retain moisture. Gravel will allow for good drainage, but will not be as warm.
  3. 3
    Decide how your hothouse will be heated.
    • If you are depending upon solar heat, provide a way to vent air should it become too hot. Louvered windows or flaps you can raise or lower will provide ventilation. Consider using a shade cloth to keep temperatures down during very hot days.
    • You may choose to install a heating system to keep temperatures constant. Your hothouse may need to have access to electricity. Attaching your hothouse to your home will let you heat it using your home heating system.
    • Keep the temperature at about 80 degrees F (27 degrees C). Anything hotter or colder will not allow optimum growth.
    • Keep air fresh by allowing for ventilation. Don't make your hothouse airtight. Keep humidity levels up by using a misting system or by using tubs of water in the hothouse to add moisture to the air.
  4. 4
    Water and fertilize as needed according to the types of plants you are growing and what they require to thrive.
    • Tomatoes and cucumbers will need feeding each time you water. Other plants may need less. Check with a local professional gardener or online to learn about recommended watering and feeding levels for the types of plants you are growing.
  5. 5
    Order or purchase seeds from a reputable garden center.
    • Plan your year's vegetable crops before placing your order so your hothouse garden will be well thought-out. If you choose to transplant seedlings outdoors, do so according to your climate zone.
  6. 6
    Walk through your greenhouse or hothouse daily.
    • Check on the progress of your vegetables, make adjustments to the amount of heat, ventilation, and light.
    • Take care of daily routines such as watering and fertilizing. You can stop small problems from becoming crop failures by catching plant illness, infestations, and other problems early, before they've done irreparable damage to your plants.

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Categories: Growing Vegetables