Melbourne greenhouse build - looking for advice (and plants!)

[wachumacallit]

I picked this greenhouse up at auction for $100, as good as brand new (flat-packed). It retails for 5x as much, which would not be such a great deal. I assembled this myself, so it's not too difficult, but the factory work was a bit rough in places. My goal was to provide a home for a few species that have failed me (or rather, I failed them) in Melbourne winters past. 

 

A few potential issues: 

 

There don't seem to be anchor points, so how to prevent it from blowing away in a strong wind? My bigger concern is tree branches (and old fences) from neighbouring properties, falling through the polycarbonate sheeting or bending the aluminium frame. 

 

There are plenty of gaps (up to around 5cm) where the ground isn't perfectly level -- does the bottom need to be sealed against pests? Or would the added ventilation be a good thing? 

 

I was thinking of installing a small raised garden bed under the highest point, but it's a tight squeeze. Any thoughts on that, or -- conversely -- planting directly into the ground? 

 

One thing I might be inclined to do is install a bale of straw or barrel of water, for additional passive solar heating in winter. I'd welcome any thoughts on interior layout and design.

 

Any greenhouse gurus out there care to offer me some pointers?

 

Happy to trade arid for (sub-)tropical plants. 

 

 

Edited July 31 by wachumacallit

[Wood Chuck]

Good purchase, can not give much advice as I am thinking of building one myself, to regulate weather conditions. Have picked a place that is away from trees, as branches do fall and where it can get full sun, have heard of people putting shade cloth over them to reduce sun exposure. Would put it on a raised garden bed, to stop the floor getting wet, not sure about the floor base. At the moment am thinking of pine pole frame, that I wouldn`t have to worry about it blowing away, ploy carbon sheets or rolls of greenhouse plastic? I to am after any information about greenhouses that may help with decision making.

[TheMooseZeus]

I'd level it if you can, better safe than sorry after your hard work!

As for blowing away, is there anywhere you might be able to get oversized tent pegs in?

As for planting, I'm a big fan of massive pots in rentals unless they are annuals. Pots gives you options to upgrade if you want something larger too.

Also shelving to take advantage of the vertical space.

 

I have never had a greenhouse of my own but have worked in large glass houses before

A small fan and digital thermometer that can record max and min temperature will help a lot

 

It looks great! Nice find

[Starward]

  

 

Quote

There don't seem to be anchor points, so how to prevent it from blowing away in a strong wind?

 

Drill 4 to 6 holes (6 to 8 mm) along the bottom rail say one in each corner and maybe one in the middle, and bolt in eye bolts then secure to the ground with tent pegs through the eye bolts.

 

If you need tools look up the Brunswick Tool Library

 

I would use a shovel and level the ground somewhat, so the greenhouse sits even on the floor, just like you would do when building a stable house foundation.

 

Since you rent, put plants in pots.

[manic]

I have the same greenhouse, paid the whole $500 for it! Dont regret it one bit though. Its about 10 years old now and as sturdy as the day I built it.

 

For the first few months I was also seriously concened about it blowing away, so what I did is I got 6 big star droppers (1.8m?) and smashed them in on the 4 corners and one either side mid way. You will need to get them as close to the frame as possible so you can then screw into the frame to hold it to the greenhouse, and....whalah!! It has now been sturdy as all hell for 10 odd years and shows no sign of going anywhere 🙂

 

I would also recommend buying another window pannel with the heat activated opener thingy like this one on ebay (I have not checked that this link is the correct size), they work great but without two I found summer just got a bit too hot in there. Mine is set up ontop of dirt and I plant directly into the dirt.

 

In terms of passive heating during summer, dont bother! I have tried everything, I even put a small 1000W heater in there one year but I gave up on it and that was 10 years ago, I couldnt justify the cost of electricity now. It is simply survival of the fittest now.

 

You wont get things like T. Iboga or P. Viridis to grow in there, the heat and humidity are not high enough or consistant enough. Trust me, I have tried, and many others for that matter. I think one of the most useful things for me is being able to sow all my veggies in seed trays in the greenhouse to get a head start on things. One little tip - Sally absolutely thrives in this thing! Perfect amount of humidity.

 

All in all I think there a pretty great little greenhouse and for $100 you got yourself a steal, you would not have one the bid if I was at that auction. 😁

[manic]

Actually, one other thing to add. 

 

Some ideas regarding the insulation. Like I said it has zero degree of insulation as it is, just thin plastic that offers nothing in terms of retaining heat.

 

I tried a 100L water barrel after first trying a 200L water barrel and it esentially they both did did jack shit. It would work well if it had a water heater in it but then your paying quite a bit for electricity.

 

My enthusiasm has somewhat lapsed since first buying it but one idea I had, and I think it could work really well, was to line the polycarbonate wall sheets with a large bubble wrap type of material, this would be the insulation factor, even better yet, if you could bubble wrap the walls and then add another interior layer of polycarbonate sheeting against the bubble wrap then I think that would work wonders.

 

Then it would be worth using a water barrel with a small solar powered water pump to pump it around the top of the roof of the greenhouse in a black poly line, as hot air rises right? This way the water would be heating up during the day due to the black poly line and the addition of being in the hottest part of the greenhouse.

 

Food for thought anyway, I am a really thinker more so than an actually do'er sometimes!

[wachumacallit]

Star pickets! That's dedication! I was never too sure about making the structure too rigid and airtight -- wouldn't ventilation give the structure some leeway and flexibility, better for withstanding strong winds? 

 

After buying a few tent pegs I realised that there was actually some concrete and stone under part of the site, so they weren't of much help. What I ended up doing was laying some spare concrete roofing tiles in the corners, with potted plants on top of them. We've had several bouts of gale-force winds and the greenhouse still stands! 

 

But one of the corner panels popped its seam, I had to loosen a few bolts and fudge it back into place. Teething problems, I hope. So far, so good.

 

Even with sub-optimal ventilation, the greenhouse effect works -- if anything, it might get too hot during summer. I'm hoping humidity will increase, the more plants I add. 

 

Good to know about the water barrels, saves me a lot of trial and error. 

 

 

 

[manic]

Nah the ventilation windows dont affect the integrity of the greenhouse at all. The frame is pretty sturdy and the windows dont affect the frame.

 

My concern was never really the thing falling apart, more so the entire thing flying off into the abyss 🤣

 

Best of luck my friend!

[wachumacallit]

We had 125km/h winds in Melbourne yesterday. The greenhouse still stands, but a couple of polycarbonate panels came loose. Not so easy to slot back into place, either. That seems to be the one weakness with this design.