Easy Homemade Indoor Greenhouse for Pots

The following technique is best used for over wintering potted plants, to keep them warm when waiting to transplant them to your garden. You start the process by building a table. To do this, all you’ll need are some two by fours for the legs, something to affix the legs to the ground and a sheet of exterior grade plywood, four feet by eight feet.

Or if you have a ready made table that size, you could use that, though it still needs to be fixed to the floor to minimize disturbance to your plants. If you use plywood, make sure that the top side is sanded and painted or varnished, to repel standing water from the surface of the table. This table will hold up to 18 trays of 72 small pots each.

Now, all you need is a thermostat placed in the middle to regulate heat, and a source of light. It doesn’t have to be special indoor greenhouse lighting; eight double 40-watt fluorescent lights on chains will do the trick. You’ll need to water the plants yourself, since there is no mister or watering device in this design.

A More Elaborate Design

If this isn’t enough to meet your needs, it’s possible to make a homemade indoor greenhouse that resembles the mini greenhouses which you can buy ready made. For this, you’ll need to start by constructing a freestanding shelving unit of up to four shelves. Again, the unit will need to be fixed firmly to the ground somehow.

Once this is done, you can retain heat and moisture by covering it with plastic wrap, or even an old shower curtain, held together with duct tape. Heat pads can be bought in any drugstore and can be used to provide heat by placing them at the bottom of the greenhouse. Make sure you buy a thermometer to measure the temperature in your homemade indoor greenhouse.

You can give your plants moisture by placing a cup of hot water in the greenhouse, and light using an ordinary desk lamp. Halogen lights are not recommended for this purpose as they are expensive to run and give off harmful emissions. A 26W bulb is sufficient, though a higher wattage bulb is better.

Next you need some soil-filled containers to set your plants in. Arrange them on the shelves, add some water, and step back and admire the fruits of your labor in your homemade indoor greenhouse.

There’s a lot of latitude as to what materials you’ll need to use, depending on your needs and budget. A DIY indoor greenhouse can be a relatively simple affair made from ordinary household building materials, but we will be concentrating here on a more complex effort aimed at the serious gardener.

The first thing you’ll need is something to build the frame out of, usually wood, metal or plastic. A frame can be constructed in up to four tiers, like a shelving unit, to create a lot of space with a very small footprint. Once you have built your frame, you need to cover it with something to regulate heat and humidity. Plastic sheeting can be used, preferably of a commercial greenhouse grade made especially for this purpose.

You’ll then want to give thought to climate control in your DIY indoor greenhouse. It’s possible to buy all in one units that combine heating, cooling and air circulation functions, all controlled by a thermostat. If you decide to go that route, it is probably worth paying a little bit of extra money for a unit that has a remote sensor that measures the heat all around your greenhouse, to ensure that it is evenly distributed. Otherwise, you may find that all the heat rises to the top and leaves the plants nearer the ground out in the cold.

Watering your plants is, of course, essential. If you’re able to devote the time and attention necessary, hand watering using a watering can or hose is perfectly acceptable. But if you’re out of the house most of the time, you might want to invest in an automatic watering or misting system with a timer attached, to ensure that your plants are watered at regular intervals.

Finally, soil. If you’re not growing your plants in a hydroponic greenhouse, you’ll need a good potting soil or peat. Garden soil isn’t usually acceptable, as it tends to be high in clay, which makes it hard for your plants to get the nutrients they need.

Use these suggestions as a guideline, and throw in some imagination and finesse, and you will most likely be able to design and build a DIY indoor greenhouse that you are sure to receive much enjoyment from.

The first thing to consider is how much light your indoor greenhouse will need. This depends on two factors, the size of your greenhouse and the type of plants you are growing. Tall plants need more light to grow than small ones, and fruits and flowers need more light than herbs and ferns. For outdoor greenhouses, the general rule is 25 watts per square foot of garden space, but for lighting indoor greenhouses, many gardeners use double or triple that amount. It is impossible to give your plants too much light, so use as much as you can afford.

There are many different types of indoor greenhouse lighting, each of which has its own advantages and disadvantages.

HID stands for High Intensity Discharge and is the most energy efficient type of indoor greenhouse lighting available, but also the most expensive by far. HID lamps come in two varieties, Metal Halide (MH) or High Pressure Sodium (HPS). MH lamps produce light in the blue spectrum, which is best for green leafy plants. Flowers and fruit work better with HPS lamps, which emit a reddish-orange glow similar to that of a sodium streetlamp. Red spectrum light stimulates growth hormones which helps these types of plant to grow.

Fluorescent grow lights are less expensive than HID lights, but they are also bigger and bulkier. For this reason, they have traditionally had a bad reputation among greenhouse gardeners, though this is now changing thanks to the production of more efficient fluorescent lights with a higher output. Another advantage of this type of indoor greenhouse lighting is that it produces much less heat than HID lights.

Incandescent lights are the least expensive type of grow light, but the saying “you get what you pay for” very much applies here. They are only really any use for the very smallest table top herb garden, as they do not produce enough light to sustain most plants.

The newest type of indoor greenhouse light is the LCD grow lamp. They have rapidly gained in popularity due to their energy efficiency and lack of unwanted heat production, though tests have shown that they do not significantly outperform equivalent fluorescent lights.

No matter what kind of indoor greenhouse lighting you decide on, it’s essential that you don’t leave it on constantly. For optimal growth, plants need a certain amount of darkness. Leave the lights off for 6 to 12 hours each day, depending on what kind of plants you have.

Indoor greenhouse kits range from a tiny herb garden that you can keep on your countertop to a kit capable of turning your basement’s shelving unit into a hothouse. There is no standard list of size categories and terms like “portable greenhouse”, “mini indoor greenhouse“, “small greenhouse” and “orchid greenhouse” can have a variety of meanings depending on the preferences of the supplier. It’s best to figure out how much space you need and then try to find a kit to match it. Chances are, someone will make one in just your size!

The actual contents of an indoor greenhouse kit vary, but typically they will include the following:

• A base: this can range from a flowerpot-type structure in the smaller kits to a set of up to four shelves in the larger ones.
• Potting soil or peat: some kits, known as hydroponics kits, do without this and allow the gardener to grow plants in substances such as coconut fiber, sand, gravel or a liquid nutrient solution instead.
• A cover, usually made of the same type of glazing material found in full-size greenhouses.
• Lighting materials: given the absence of sunlight in a typical indoor greenhouse, special fluorescent lamps are required to provide the light and warmth that would normally be provided by the sun.
• Watering kit, normally consisting of a spray mechanism, timer and reservoir for water or nutrient solution.

If you’re feeling really ambitious, you could convert a portion of your basement into an indoor greenhouse. Hydroponics kits work particularly well for this purpose, as they provide all the light, water and nutrition needed to grow tropical and subtropical plants in what is probably the coldest, darkest place in your home.

You can buy a cover for an existing shelving unit that will enclose heat and moisture for your plants, or you can buy the shelves as part of a kit, with the same components as in the kits listed above. You will need to pay special attention to the ventilation and air circulation in your basement to stop the increased humidity resulting from an indoor greenhouse from rotting your wooden beams and joints.

Also, make sure you consult any family members who use the basement, to make sure they don’t object to it being turned into a hothouse!

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With a mini indoor greenhouse, it’s possible to grow fresh herbs on your kitchen counter top, as well as cherry tomatoes, chili peppers and chives. Imagine making a chili con carne or pasta dish with ingredients you’ve grown yourself. You can make a DIY indoor greenhouse with a seed bed, a wooden frame and some plastic sheeting, or you can buy a variety of kits or ready made greenhouses, containing everything you need to grow plants in even the smallest space.

If you’re setting up a mini indoor greenhouse in your kitchen or living area, it’s quite likely that you don’t want to risk getting potting soil everywhere. One way around this is to use a hydroponics or aeroponics greenhouse. Hydroponic gardening refers to the art of growing plants without using soil, while aeroponics uses no growing medium at all.

In hydroponics, the main medium for delivering nutrients to the plants is water. Some gardeners plant the roots directly into a solution of minerals dissolved in water, while others use an aggregate medium such as diahydro (a natural sediment made from fossilized algae), coconut fiber, gravel, brick shards or mineral wool.

In aeroponics, the roots are not placed into any liquid. Rather, they are suspended in the air and constantly misted with a fine solution of water and nutrients. Aeroponics techniques were originally developed by NASA, who became interested due to their potential for growing plants in zero gravity environments, but they have since been incorporated into mini indoor greenhouses designed for home use. They are less messy than hydroponics systems, but considerably more expensive. A home aeroponics garden will typically cost in the region of $150, while the smallest hydroponics systems sell for a fraction of that.

One advantage of growing plants hydroponically is that the lack of soil makes your plants much less attractive to pests. However, no plants are immune from bugs and blights. It is best to avoid the use of harsh chemical pesticides, as these can get into the nutrient solution and poison your plants from within. Organic solutions for pest control include extract of orange peel (d-Limonene), which can be sprayed onto plants, suffocating pests; herbal extracts which kill a broad spectrum of pest species; and “friendly” bugs that prey on the pest species whilst leaving your plants untouched.

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But even gardeners with yards can find uses for an indoor greenhouse. The main advantage is cost. A mini indoor greenhouse can be a lot less expensive than even a basic lean-to structure. You can buy an indoor greenhouse kit from garden supply stores or you can build your own from scratch.

It can also provide an interesting conversation feature for your home or office. Or you can use it to teach children about the fundamentals of growing their own flowers, fruits or vegetables.

Face it, lots of offices, stores and restaurants show off tropical fish to keep their customers diverted. Why not feature resplendent orchids or beautiful bird of paradise flowers instead? You can even grow your own Hawaiian lei! Exotic foliage can lend a splash of color to any home or business.

Or you can use your indoor greenhouse to grow your own fruits, vegetables, herbs and spices to give almost endless variety to your kitchen. No need to contribute to global warming by having your limes imported from the Florida Keys when you live in Maine. You can just go to the next room to get them. Add spice to your food by growing your own ginger or cayenne peppers. An indoor greenhouse brings the tropics and subtropics to your home wherever you live.

An indoor greenhouse can be a valuable educational device to teach children about the life cycles and growth of plants. The lessons learned can be incorporated across the curriculum. Maybe the children can learn about how the colonists grew herbs in their history lessons. Or they can speculate on how hydroponics, the science of growing plants without soil, can be used to terraform other planets in the future. Or grow flowers to press in their art class.

The possibilities are as limitless as the imagination. Taking the responsibility for nurturing a life can also be an important tool in the development of a child’s conscience. It can teach them that there is more to life than just their own wants and desires, and that all things are interconnected. What better lesson to teach young minds?

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