Hi

I'm pretty new to gardening and converted one of my garages into a greenhouse. I planted several things but something is stunting the growth of the plants. I should have had vegetables by now. Things seem to just die off at certain points. Several things have grown but they have not gotten past a certain size in a long while now. The green house has polycarbonate paneling on all sides above a four foot siding wainscot. The roof also has the paneling only thicker. It gets sun the majority of the day. There are two triangular louver vents on each end Of the greenhouse and a screen in the top portion of the back door.

I finally got a thermometer and today it read 110 degrees. It's very hot in there and I think it's the heat creating this stunted growth.

What can I do to make my greenhouse work? I invested a lot of money converting to a greenhouse!

If I need to climate control what's all involved?

Thank you for your assistance!

Brandon

Hi Brandon (@Gardenpsycho) and welcome to the forum!

First off, 110 degrees is much too hot. Those plants don't look stunted. They look about a day or two from being dead.

Where are you located? You need better ventilation. Louver vents and a screen are not much help unless you can move the heat out on hot days and/or shade the greenhouse. Do you have an exhaust fan, circulation fan(s), shade cloth? If you can take some pictures of the greenhouse from the outside/inside so we can see the overall structure, we might be able to make some specific suggestions.

Also, what is the composition of your soil? This may be contributing to your problem as well. Is that all peat moss or some kind of mulch? What is that white powder around the edge of the planter?

Jim

So I uploaded some photos. I'm in San Antonio Texas. White powder is dragon dust to keep the bugs away. I can specially remember what was installed . There's only one vent louver on one end.

Nice looking and spacious greenhouse, Brandon. Being in Texas means your greenhouse is going to cook!

You could consider the following:

Install an exhaust fan on one side (high) with an intake on the other (low). You want to size the exhaust fan to be able to change the air in the greenhouse in 1 1/2 minutes. Fan capacity is rated in Cubic Feet per Minute or CFM. Here is a guide you will find helpful: http://www.charleysgreenhouse....

Aluminet shade cloth will also help to control the heat and intense sun: https://www.aluminetshadecloth...

Evaporative cooling equipment can be of help, but it is expensive. For a hobby greenhouse such as yours, you could look into a fogger or humidifier. Both foggers and humidifiers emit water droplets so small that the plants within the greenhouse will not get wet. Instead, the water quickly evaporates and helps to cool the greenhouse. You would want to use one in conjunction with fans to circulate the air around the greenhouse. A very cheap way to do this is to spray down the floor several times on hot days.

The above links are for your information. You should shop around for the best prices, but these would get you off to a good start in controlling the heat in your greenhouse.

Oh man that is not an oven its a pressure cooker! Very nice one though! My greenhouse is 48 x 36, approx 1740 sq ft, and I have the entire back 36 ft as a vent that is also a swamp cooler. It has 6" thick 'honeycomb' (a big paper filter thing) that water can be made to run down, and the two 4 ft x 4 ft exhaust fans in the front pull the air through the wet filter and it instantly lowers the temp and creates humidity too. I live in Florida where the summers can be brutal, but my part of Florida also can get colder in winter so I needed a greenhouse, not a shade house. I also have fans up in the attic that more air around to keep it from getting stagnant.

I really like how your greenhouse looks like.