21 Greenhouse Tips To Have The Best Greenhouse

Planning on building a greenhouse or have one that just isn’t working well for you? Use these greenhouse tips to have the best greenhouse.

A greenhouse is a valuable asset in your food garden.

Yes, it cost a bit of money to build or buy a kit, but in the end it’s worth every penny!

Here are 21 tips based on my experiences building and using my lean-to greenhouse for the past 10+ years.

Build The Biggest Greenhouse You Can Afford

Build your greenhouse bigger than you think you need. Or at least plan for expansion.

Trust me on this!

In a small backyard you’ll of course run into space limitations. That’s what happened to me. But I still regret not building my greenhouse just a bit bigger.

Or if your funds or time don’t allow you to build a large greenhouse right now, at least plan for expansion some day. A standard free-standing greenhouse can easily be added to by adding another greenhouse to the end to make a longer greenhouse.

A bit harder to do with a lean-to greenhouse – I’m limited in length due to my deck on one side and a door leading out of my garage on the other side.

The benefit of having two greenhouses end to end means that you can probably have a dividing door in the middle and ventilate and heat both sides differently for different types of plants.

The other alternative is simply to erect another greenhouse in a different location on your property if you have the space. However you do have then double the expense plus need to provide all the greenhouse amenities in each greenhouse that tips below will cover.

Insulate The North Wall Of Your Greenhouse

Build the north wall of your greenhouse as a well-insulated wall as it doesn’t contribute to solar gain at all.

If you live in the Northern Hemisphere the sun “rises” in the east, “moves” to the south and then “sets” in the west.*

That means that the north wall of the greenhouse doesn’t get any direct sunlight. And the main reason to have glazing (glass or plastic) on your greenhouse is for solar gain. When the sun shines into the greenhouse, it heats it up.

Therefore adding windows to your north wall does very little to help solar gain and in fact can release all that heat from the day into the night, as glass or plastic does not insulate as well as a solid wall.

The north wall therefore should be build like a house wall, either out of brick or lumber.

If building from brick, the wall will heat up during the day as sun shines into the greenhouse. It helps to paint the wall inside the greenhouse a dark colour such as black to maximize capturing the sun’s heat.

If building from lumber, insulate the wall with regular house insulation. Ideally avoid using a window in this wall as you should get enough light and ventilation from the other walls.

If you’re using a kit greenhouse which usually has metal framing, you can leave off the glazing on the north wall and then build an insulated wall in place of or just outside the kit wall framing.

In my case I butted my lean-to greenhouse up to my second floor deck and build a small garden shed underneath the deck. So my greenhouse’s north wall is shared with the garden shed and I have easy access to my tools and supplies I store there, leaving more room in the greenhouse for plants!

Build Insulated Greenhouse Knee Walls

In addition to having a solid, insulated north wall, you also want to reduce glazing on the other walls to the minimum you need.

If you’re growing mainly on benches and raised beds, you can build knee walls on all or most of the walls, since you don’t need sun or light at the very bottom.

Similar to the north wall, you build these as insulated walls, about knee high. In my greenhouse they are about 3 feet high (approximately 1 meter). Framed glazing then goes on top.

These are easiest to incorporate into your greenhouse design if you’re building a greenhouse yourself like I