Greenhouse Gardening 101: Considerations for Year-Round Greenhouse Growing

Growing year round is a different beast than just using a small greenhouse for starting seeds. When growing year round, the building needs to be made of sturdier stuff. Glass or treated thick plastic are both good investments for this type of adventure. Cheaper materials will age in the weather and will need to be replaced up to a few times a year.

Use treated wood or metal benches inside the greenhouse to avoid rot. Moisture in the air will eat away at untreated wood.

This could be bad news if you already built your greenhouse with cheap materials. But, if you haven’t yet, make sure to consider the material. Here’s a collection of 84 greenhouse plans to get you started.

2. Add Extra Heating

Heating the structure is a must for year round growing. Depending on the style of your greenhouse you can heat in a few different ways. Some have electrical heaters that can ensure a steady temperature, but these can increase a power bill.

To add an extra measure of heat to your greenhouse, you can compost inside. As organic matter, such as leaves, eggs shells, and shredded newspaper decays, it gives off heat. By having a compost box under raised planting tables, you’ll be providing extra heat to take some of the work off the heaters.

Jugs can also help heat up the building. Milk jugs or empty cat litter jugs painted black and filled with water will heat up considerably when left in the sunlight. Over the course of the day, the jugs will absorb the heat and radiate heat once the sun has gone down.

3. Get Rid of Excess Heat

Controlling the heat in the structure can be hard, but that’s why we have vents. Whether they’re hatches on the roof or just small push open vents on the side walls, air vents provide a breath of fresh air and a cool breeze for stifling heat.

To improve ventilation don’t over crowd your greenhouse. If the leaves on the plants are touching, you should move them slightly apart to provide both room to grow and room for air to get through. If you’re not home during the day, you may want to invest in an automatic ventilation system. These systems will turn on either by a timer or by sensing the humidity and heat in the greenhouse. They will shut off in the same way.

Shade clothes can be used on hot days to help cool off the temperature in the greenhouse. Simply spread it out on top of the building to create artificial shade. These net like blankets can be stored on a shelf in a corner and brought out when needed. To quicken the cooling effect you can soak them in cool water before draping them over the greenhouse.

4. Pests: The Worst Garden Enemy

Pests are going to be attracted to your plants inside just as they would be if the vegetation was being grown outside. This means you’ll have to keep a watchful eye out for them. Some of the more common greenhouse pests include aphids, mites, and whiteflies.

If you spot them, you can try a number of manual removal options. Vacuuming and squashing are the first attempts at control. If you spot pests on one or more plants, immediately move that plant away from the others. Quarantining isn’t an end all to pests, but it will help reduce the chance of non-flying pests spreading too quickly. Wash the plant with soapy water to remove pests. Make sure to rinse off the soap once the wash is complete. Depending on what type of pest has arrived you may need to transplant the affected plant into new soil. Put out sticky traps around the affected plants or area. Fly strips work well for flying pests, and sticky pads that lay flat on the ground or bench can also be used for crawling pests.

A neat trick I learned was a mixture of pepper powder and vinegar. Mix several tablespoons of pepper powder, the stronger smell, the better, and three cups of vinegar together to create a very foul smelling pest repellant. Circle the greenhouse with a single line of the mix and it’ll detour insects, small mammals, and other creepy crawlers.

Be sure not to get any vinegar on your growing soil as vinegar will kill soil. Replace the circle after a rain shower or once a week.

5. Plant Diseases: The 2nd-Worst Garden Enemy

Like pests, diseases must be controlled quickly. Diseases can spread very fast in a greenhouse and before you know it you’ve lost half of your plants to root rot or another fungal disease. While checking for pests, it’s a good idea to check on the health of the plants themselves. Wilting or discolored leaves are often the first signs of a problem.

Quarantine any sick plants from the healthy ones. If possible set up a small area in your greenhouse just for sick plants. This will make it easier for you to act quickly in caring for the plants. Never reuse soil. Even soil left over from the transplant of a healthy plant can be dangerous. Fresh soil is always going to be the best option. Wash out containers and planters with soapy water after they’ve been emptied. If the plant that came out of them was sick, you can use bleach. Make sure to rinse away any chemical residue that may be left behind.

Maintain the health of your plants inside the greenhouse by being careful what outside plants you bring in. Inspect any new plant for disease or pest before adding it to your greenhouse. If you do spot problems treat them and if not put the plant in a corner by itself for a week or so to keep an eye out for any problems that may develop.

Jennifer Poindexter and her husband raise most of their food and a variety of animals in the foothills of North Carolina, where they built a small homestead on very little money. She writes about all of her adventures at Morning Chores, where she shares the knowledge she has gained with others that might want to take the full plunge into homesteading.

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