My brother recently built a 20' x 10' greenhouse in a designated area in his yard. We're hoping to build some boxes inside this week/weekend and we're struggling with the layout. We're hoping to grow a variety of onions, carrots, tomatoes, herbs, and some fruits (if possible). I've poked around the internet for layouts to help guide our project, but the solution for us isn't clear to me yet. Should the boxes be in a single U-shape arrangement? Does it make sense to have three isles?

If you're using the greenhouse for starts/seedlings that will be moved, build up with multiple layers of shelves.

If you are going to build planting table beds, Fewer wider beds are better than multiple narrow beds. One 30" wide walk way is plenty. Two 15 are not... Plus the width of your lumber.. not efficient use of space.

What do you have set up to vent it, because overheating is one thing you can't come back from. Everything else is up to personal preference.
You can have one sunny 75 degree day in April and fry everything if you don't have a plan for venting. I thought I'll just keep an eye on the weather.. had one unreliable forecast.. a 62 degree expected high turned out to be 70+ and by the time I got home months of work was cooked and an entire growing season wasted.

Hi @curious_seedling and welcome to the forum!

Like @Turbosaurus wrote, how you set up your greenhouse will depend on what you want to use it for...i.e. seasons and types/sizes of plants.

At first I had a "permanent" layout (read: fastened in/unmovable), but I soon learned that my layout needed to be more "fluid". Since I use my greenhouse for 3 seasons (vegetable and flower seedlings in the spring, growing full sized pepper and tomato plants in the summer, and fall lettuce and spinach beds). I went from a wooden/stationary set up to concrete blocks and Dura Bench Plastic Bench Tops (https://www.greenhousemegastor...). This gives me the freedom to easily change the setup depending on the season and my needs.

Turbosaurus - Thank you for your response! The current plan is to build approx. 2' high beds. For the sake of using less wood, having fewer things to build, and more planting space, I'm leaning towards a u-shaped layout. At this point we have no active venting in the greenhouse. There is a zippered opening to help vent, but I'm getting the impression that we may want some sort of fan present too.

MoonShadows - Thank you for your response too . I really need to sit down and get a better mental picture of what we're going for.

U shape is probably best.
I think moon shadow has the right idea here...
it sounds like you're thinking of building permanent planting tables.. basically a raised bed on legs, right? Tell us more about the purpose of the greenhouse. Will it change seasonally?

As for ventilation, there are passive methods, based on vents and convection currents that cool, that work based not on absolute temp, but the difference between internal and external temperature. some semi passive, like hinges that open based on passive expansion (temperature) of wax or fluid inside to open vents at a specific temperature.
Fans and other electric equipment, sensors (wired or solar) give you the most control, but they are also the most expensive. Do some research to figure out what will fit your design, materials, budget and lifestyle

As a newbie to having a greenhouse ( 12 x 8 kit from Costco) I found looking for ideas on how to best set up a greenhouse lacking. After much thought and consideration, I built a potting bench and a bench for starting seedlings and on one side and will use my grow bags for vegetable plants this season on the other. I expect it will change as I learn what it is I want out of it.

MoonShadows's recommendation to be flexible is well founded. If you set up raised beds it would be a lot more work than just moving containers, if you change what you want.

Good Luck !

Hi @DavePete and welcome to the forum!

When I first started with my greenhouse back in 2016, I remember searching around for info about interior gh setup. You are right; info is rather lacking. Each year I have changed my setup looking for the "right one" for me. Now, in year 5 with my greenhouse, hopefully I have found it.

I initially set up our dome greenhouse with raised beds on both sides of the water holding tank. It was a job building, insulating, and filling the beds. It took an incredible amount of soil mix to fill them. Then when growing, if a plant needed treatment, it was hard to treat it without spraying the glazing or hurting other plants. If you have container plants it's much easier to remove them, treat them or quarantine them.

I'm now thinking of removing one raised bed so I can have shelves for plants. I think that would be much easier for me to manage. It will be awhile though, as we both have to recover our health and strength.

MoonShadows said:Hi @DavePete and welcome to the forum!

Each year I have changed my setup looking for the "right one" for me. Now, in year 5 with my greenhouse, hopefully I have found it.

What a tease! Tell us what worked, what didn't and why..

I've always (and still) wanted one, but after I put up a little $50-on-sale-at-target-more cold-frame-than-greenhouse and completely fried everything on one hot April day I haven't really felt knowledgeable enough to design and build and use something since.. so it stays an informed pipe dream. Please share your experiences

I have a 10x12 HF greenhouse. What has worked for me so far is Rubbermaid metal/wire shelving. I have 3 levels on each side of GH. So I have about 60' of shelving. Shelving is 16" wide. This stuff comes in different widths so you have a choice.
I have my GH supported with 2x4 wall studs and ceiling/roof rafters (last Winter I had 2' of snow on roof at times) so I hang the shelves from these supports. The shelves hang from ceiling supports by chain and attached to wall with pipe clamps.
The best part of this system is that the chain and clamps enable the shelves to "swing" up and out of the way when not in use.
This works for me because I use the GH mainly for seedling plants in trays in early Spring.

I just planted mine as much as I could. I have a mix of things in the ground and things in containers. I move the containers around and even outside in warmer weather to use as porch plants and pool deck plants. But I don't grow food crops. Strictly ornamentals, all tropical.

I keep everything in pots. Some things I leave in the greenhouse and others I plant outside. All the flowers go outside. Some tomatoes, too. But, other tomatoes and all peppers stay in my two greenhouses all summer.

I have most things planted but do have a lot of containers too. I move them around continually and some go outside for the summer. My greenhouse is saving me during this shutdown and quarantine.

I keep come containerized because I wasn't the option of a quick removal in case of an emergency. Plus I rotate different ones outside every season so I have something new sitting out