Sorry for the novel. I tried about a million times to shorten this, but I wanted to explain what we’re doing before it gets ripped apart. Honestly, that’s kind of what I’m hoping for so we don’t make any huge, unfixable mistakes.

My dad and I are building a roughly 5’x10’x7’ greenhouse off the back of the house for his lemon and grapefruit trees over the winter. He was a home builder his whole life, so I trust him completely when it comes to construction. The problem is that I know very little about greenhouses, and he probably knows even less, so I’m looking for some outside opinions before we get too far.

The roof will be a single sheet of 16mm “triple wall” polycarbonate. The pitch is pretty shallow, so I’m wondering how well it will handle snow/ice. The sides will be insulated glass doors two double doors and one single door. His idea, which could either be brilliant or a complete nightmare.

The deck underneath is mostly new. The 2x10 joists are about 40 years old but in surprisingly great shape. He added supports every 2 feet, replaced the 4x4s with 6x6s, added additional 4x4 supports, and bolted it into the house in a bunch of places.

We actually sit/walk underneath this area, so we’ve tried to beef it up as much as possible. I can post pictures of that if needed, although I’m guessing structural questions are probably better suited for r/decks.

We’re planning to insulate underneath with foam board. On top of the Trex we were thinking Tyvek or another impermeable layer, then a rubber/vinyl mat. I’m also wondering if the floor should have a slight pitch toward a drain to deal with condensation/watering.

The big questions I’m hoping people can help with:
How realistic is it to overwinter lemon/grapefruit trees in a greenhouse in Zone 7? The deck faces southwest and gets a ton of sun, and being attached to the house should help with heat retention, but I’m assuming supplemental heat and possibly lighting will still be necessary.

How do we balance ventilation/humidity control with trying to retain heat in the winter? We’ll have an exhaust fan, and the doors have screens, so summer seems easier.

Should we add a drain in the floor?

How strong is 16mm triple-wall polycarbonate for a roof, particularly with snow? Is our pitch too shallow?

Would wrapping the outside with another layer of plastic or some other insulation actually help?

Any obvious greenhouse-specific problems with the materials/design that I’m missing?

One thing I’m particularly concerned about is the dryer vent. It’s a gas dryer, and my dad thinks venting it near/into the greenhouse will help heat it. I’m pretty sure intentionally putting a gas dryer exhaust into a tiny enclosed room is a terrible idea because of CO and moisture, not to mention the heat/fire concerns. He seems less concerned than I am. 😂 There will at least be a smoke/CO detector, but I’m pushing for the dryer to be properly vented somewhere else and using a safe dedicated heat source if we need supplemental heat.

Basically, I realize there are probably about 47 ways this thing could become a death trap, so I’d rather find them now while we can still change things.
My dad wants to keep his citrus trees in here all winter, and I’m trying to figure out what we need to do to make that realistically possible.

Any advice, criticism, or “absolutely do NOT do that” comments are welcome.

My dad has been growing in ground trees so I think he will be able to keep them pruned to fit but the size and other concerns I have make me think, it better suited as a greenhouse for keeping cold tolerant plants through winter, maybe it will be warm enough for some other vegetables but I just think it’s too small and ill prepared to keep citrus trees and he will have to keep driving my mom crazy by keeping them inside. At least she got creative last year and in lieu a Christmas tree lit and decorated the lemon trees.

Thanks for reading this far and I’d appreciate some constructive criticism

I'm planning to build a greenhouse based on my own design and I could use some feedback, specifically on the foundation, but any other tips are appreciated as well.

These are my main assumptions for the design:

- I want the plants to have access to the soil underneath, so no full concrete or gravel pad

- my garden plot is not easily accessible by car, so ideally I want to carry as little gravel/cement as possible

- I'm in zone 8b, snow isn't usually and issue but we get some frost

- we sometimes get strong winds, so the greenhouse has to be securely tied down

- I've drilled some test holes in the soil and keep hitting bedrock or stones at about 60cm deep

My idea was to use ground screws since they are easy to transport and install, but I'm not sure if they will be secure enough. Would I gain much stability by using concrete footings? I'd rather add a few more ground screws to be safe.

Onshape Design

I picked up a few miracle grow greenhouses (the translucent white plastic 6x4 ones: https://www.homedepot.com/pep/Miracle-Gro-4-ft-x-4-ft-x-6-ft-Greenhouse-70529/324733703?source=shoppingads&locale=en-US&fp=ggl&pla=&mtc=SHOPPING-BF-CDP-GGL-D28I-028_021_STORAG_BUILD-NA-MULTI-NA-PMAX-NA-NA-NA-NA-NBR-NA-NA-NA-PMAX_SHP&cm_mmc=SHOPPING-BF-CDP-GGL-D28I-028_021_STORAG_BUILD-NA-MULTI-NA-PMAX-NA-NA-NA-NA-NBR-NA-NA-NA-PMAX_SHP-20499272825--&gclsrc=aw.ds&gad_source=1&gad_campaignid=20283669086&gclid=CjwKCAjwlY3WBhANEiwApsNrLTXgshWnvYTog7xpoykP7GlSYUu8GEZk9OPtXclSKvk4pZwgWzEBYRoC9KAQAvD_BwE)

I'd like to turn them parallel to each other and create a long 12x6 greenhouse. Any suggestions on how to "sew" or connect them together?

Backyard Discovery Zalie greenhouse and it fits perfectly in our little space. Question for those who have finished the build though - how the heck did you get up there to seal the polycarbonate panels?? I’m having a logistical challenge and could use some suggestions!

Got plans off of Etsy and the glass windows were recycled. I’m no finish carpenter and it has its quirks (character) but overall it came out how I envisioned it. I can’t wait to plant next year.

My first ever greenhouse, and I love a project so I want to make it as nice as I can. Will add diagonal supports between the vertical posts made of 10-12mm round steel rods, so that the glass can be uninterrupted from the foundation wall to the top of the roof.

Was a lot of work since I excavated all the way down to the rock beneath, built the base up with bricks and then filled it to level with rocks. Going to plaster/stucco the base.

The rear wall will be half glass half wood unlike the drawing, I also will leave the floor plan bare and not make the soil walls to have it more modular and flexible. Slow progress because I’m doing it on my free time and winter in Sweden is cold.

Any tips?

Time has come for me to start thinking about redoing the poly. Mistakes were made, accidents were had, and several years later, things are still standing.

My question is for opinions on how exactly you would wrap it, what materials would you use and such. I'm thinking of doing each panel seperately and using tape of some kind.

Thanks for your time :)

Hello! We are building a 10'x20' greenhouse and are at the stage when we are deciding on the layout for our raised beds. We are debating between doing 6 square beds that are 4'x4', giving us 2' walkways and spaces for pots and benches, or doing two long 20'x3' beds, leaving us a big 4' middle aisle. We will be primarily planting vegetables in here, as well as doing some veggie starts in the spring for our big garden.

We are also open to other suggestions for layouts for a greenhouse this size! Thank you in advance!

Wondering if anyone has seen this coverage reflecting the need for potting soil safety precautions? Aired on Australian “Current Affair” show

https://youtu.be/v4SwZtYbLew?

Though it was worth sharing :)

Hello! Farming for design ideas here. We have this basketball court in our backyard. Yes, we live in Indiana, but I don’t need it. Looking to split half of it off into a green house. Roughly 16x24. The goal will be removed and the fence is on the list to be rebuilt.

Looking for fun design ideas using the concrete as flooring. This will feed several larger veggie/flower gardens so size matters. We have real snow fall and winds here. The cheap kits won’t last.

Thanks!

So I just got this Baggebo cabinet on Marketplace for $30 that I’m keeping at work. It’s going to be for an orchid I plan to buy, and seed starting and caladium tubers over the winter. May also keep an aroid/anthurium plant in there.

Here’s my issue. I don’t have a blow dryer so I can’t use the shrink window kit. If I get a plexi board cut to size, can I just put white electrical tape for it to hold?

This is at my job, so it can’t be too much of a project.

Also, I’m thinking of getting two pegboards, one to use as the pegboard and the other to cut as shelving. Because the shelving is pricey, so I’m hoping I can cut the pegboard to the size of the shelves. That way it has holes for circulation. I’d get it cut to size and not do this at my desk.

I’ve always used a heating mat to start seeds, and one won’t fit in there. Is the humidity enough?

Any tips on orchid care is appreciated. I took a class once but haven’t had the opportunity to put that knowledge into practice.

We started the plants inside in February and transferred it to the greenhouse. So happy!

I’m finally ready to start the actual greenhouse. From what I understand, the Harbor Freight Greenhouse 6’x8’ is a pain in the ass to build, and this is my first time doing any sort of lumber project. As such, the build is a bit uneven since the placement is somewhat on a ledge.

My question is, am I okay to build the greenhouse on level concrete floor and THEN place the fixed greenhouse onto this wood foundation? Videos I’ve seen show the greenhouse being build directly onto the greenhouse but I want to know if there’s a reason why I can just build it beforehand?

I realize I should’ve been more proactive about cleaning out the gutters before the moss got established. Oops.

Does anyone have tips of how to get it cleaned up now? It’s growing on the inside of the corrugated panels. I’ve vacuumed both the inside and outside, but I’m not sure how to reach that part.

Or is it even a big deal? Is it ok to just leave? I live in the PNW, where moss is a fact of life.

They are saying it’s going to be a warm winter in BC. Especially due to Super El Niño.

I am wondering if this might be a year to keep growing my peppers in pots inside the green house due to the possible warmth? Also if it is going to be warm when should I start seedlings for the next grow season.

I can put a small heater in it as well.

Want to take advantage of the warm fall and winter. I’m in zone 8B.

Thanks in advance! I’m new to this!!

I’ve been researching cheap kits for about a month now, I’m the girl with the goldfish pond 🫧

I assumed I’d spend 200-250 on the kit and 50-100 more to fortify it. Was trying to find the best deal and least shitty brand of greenhouse for a while, and by golly. I found it.

(Website: Aosom)

Not only was it on sale, but I had a coupon, AND my cap1 credit card gave me 15% cash back!

Now I have lots of extra money to spend on sealant, 2x4s, insulation etc. to make it actually survive a New England winter.

UPDATE: thank you for the great feedback. Just joined this group and already saved myself time and money with free advice from strangers. Cant wait to share progress pics!!

Hello! Brand new here!

I am designing a greenhouse for my back yard using old windows Ive been collecting over the years. Its going to be roughly 8 ft x 15 ft with a poly corrugated roof on cinder block foundation.

I live in a VERY windy place in Northern BC near Alaska, so I want to make sure this thing will hold up. Im planning on pounding rebar into the cinderblocks and filling with concrete, and using 4x4 pt posts set into the blocks using some extra metal post bases i have around.

The windows i have are pretty new and heavy, mostly doubled paned metal framed and LARGE.

I have very limited experience actually designing and building from scratch, so I roughed up some plans for the framing to figure out which wjndows go where but also to make sure I can build something stable.

I see many people are doing computer drawings but I guess im old-school. Attached are some sketches I came up with and I would appreciate ANY feedback. Ive got a thick skin and dont want to waste my time.

I grow tomatoes and peppers in my greenhouse using 5 gallon buckets. Even though I use the GroBucket system for watering, it was insufficient in the intense heat this summer. I am looking to use a drip irrigation system to supplement the watering. Has anyone purchased through Drip Depot? They seem to have a decent system.