Beginner's greenhouse?

Hi all

I'm going to buy a greenhouse for this year's season but as I've never used one before I'm a bit confused as to which model to buy. My budget is about £350 and I've seen a few (online) which look good, but I'm not sure whether it would best to get polycarbonate or glass panels... All the greenhouses I've seen offer toughened glass for a higher price, but I can't afford this so it's a toss up between normal glass and polycarb. We don't have kids but next door do, so there is a small risk of footballs etc hitting the greenhouse!

Also, we are thinking of putting the greenhouse straight onto the grass - is this a mistake? As long as the ground is level, is there any reason why putting it onto grass is a bad thing to do? The garden is well below the level of the house by the way.

We're thinking of orienting it with the long side facing SW, does this sound like it would provide enough light? We can't orient it due south so the choices are either SW or SE.

I've also read a couple of the posts on this page and a couple of people have mentioned shading the greenhouse in summer - I've never heard of this, is it definitely necessary? I live in Yorkshire (have recently moved) so the summers aren't that hot... We were planning just to get the greenhouse and not heat or shade it, is this bad? We're going to use it to grow peppers, aubergine etc and protect young seedlings.

Any advice would be very welcome! Seems greenhouse growing is more complicated than I thought!

Paddy

 

Hi Paddy, once you have your greenhouse you will never look back.

Siting it on grass is fine. You could then dig a border and edge with something like scaffold boards along one or both sides and lay paving down the centre, or pave the inside and use growbags for your toms etc. It would be good to put in some staging or a bench for putting seed trays on. I also use the shelving from those cheapo mini-greenhouses to put the trays on.

The orientation should be fine. Shading is usually used in the height of summer as the temperature soars and your plants sould get scorched. I put up a bit of fleece on the inside using those turn-button things, it is easiily removed on dull days.

You will also need air vents for ventilation.

I have never used polycarb so I'm unable to help you on that one.

We got our greenhouse second-hand in the local paper, have you looked to see if there is anything going near you?

 

Mine are on 2 courses of bricks, which are on a shallow bed of concrete. I don't know why / if that is beneficial. Paving slabs might be a half-way-house?

You can shade the greenhouse (if you need to - I don't bother, but many people do) with a sort of whitewash so you can put that on when / if you need it in the heat of Summer, and scrub it off in the Autumn when temperatures fall and you want more light again.

Cooling a greenhouse is best done (IMHO!!) by convection, and not by "draughts". So open the top vents and then have some sort of low down vent (out of the wind) that will allow cooler air in at the bottom. I would suggest a louvre in the far end wall, but leaving the door open a crack works as well (but it lets the air in all the way up, not just at the bottom of course).

You then need some roof vents. I have some on each side, and I open the ones away from the wind (i.e. to get convection rather than draught). But I've got a 30 foot greenhouse, so the temperature is easier to control than a smaller one, so you might find on hot summer's days that you have to "throw everything open" to cool it down

If you are not at home during the day I would advise getting some automatic opening devices. Basically a piston with some sort of wax in it that expands and pushes the vents (and louvre) open. So if the sun comes out unexpectedly the plants don't fry!

You could consider irrigation also. Crops like Tomatoes will benefit from little-and-often watering, so a drip system would be ideal. Drip irrigation can run off a water butt (if the greenhouse is not near your garden tap). Either way, a water butt connected to the gutters on the greenhouse is a Good Thing. (Normally at the far end so that both gutters can connect into it - obviously the door is in the way at the front or two water butts, one either side). You'll probably need a gutter-downpipe-connection-kit (or a string-and-chewing-gum DIY solution!). But that can be Phase Two ...

Are you going to grow in the soil? If so you will need to replace the soil each year (ideally ... tomato diseases tend to persist rather easily if you don't change the soil). My approach is to put my compost heap, and some manure etc., into the greenhouse beds, and then at the end of the season that goes out onto the vegetable beds - so basically my compost heap takes one year longer getting to the Veg Patch! You could grow your Tomatoes in large pots or grow bags. They are harder to get the watering even (which tends to cause the fruit to split), and grow bags are the hardest of all IMO. But that would allow a paved / hard floor, if you would prefer that. You can then "damp down" the greenhouse by pouring water on the hard floor - the evaporation reduces the temperature, and increases the humidity. But a hard floor greenhouse is really better suited to growing things in pots (flowers and the like, although Tomatoes in Pots / Bags too of course) and having staging.

If you are going to grow Cucumbers etc. as well as Tomatoes you ideally want to segregate them as they like different conditions. If your greenhouse will be very small then ignore this, but if you can hang a clear plastic sheet to create two "rooms" and have greater humidity for the Cues and Aubergines that will help (lots of schools of thought on which plants like which conditions, but having Humid and Drier zones will at least allow you to make a choice.

I bought my 30' x 10' greenhouse off eBay for £400 - not sure what size you are planning, but that gives you an idea of budget for second hand. But I waited a long time to get what I wanted within driving distance so I could collect it.

(There are some pictures on my Blog if you are interested)

 

Paddy, buy the biggest greenhouse you can afford, and, assuming it is twin walled polycarb, then go with that. siting it on gtass is fine, but it MUST have a base of some sort, Either aluminium/galvanised steel, of brick, or timber. The base needs to be about 4 inches high. If you just plonk the greenhouse on the lawn WITHOUT a base you wont be able to open the door.:hehe: You will also need to secure the GH to the ground so that it wont blow over.:thumb:

 

I would agree with David. The greenhouse must be secured to the ground somehow to prevent it blowing over.

 

I got a polycarbanate greenhouse to replace my old, broken smaller horticultural glass greenhouse.

18 months later I am pulling it down and replacing it with a safety glass greenhouse. I have finally reached the end of my tether :mswhl:.

First of all I have spent many a midnight, in my PJ's and dressing gown in the pouring rain and wind trying to secure several greenhouse panels to save my tomatoes, chilli's, peppers, cactus and protea. I have silicone sealed them, put on no more nails, but still the bloody things won't stay on. :flag:

Another thing the rain pours in, some days you need to put your wellies on to get in and the damp is horrendous. My poor protea is now a gonna i am affraid :cry:

I went for polycarb to save a few pounds, but it has cost twice as much in the long run, so plaese bear this in mind when you make your final choice

 

Thank you all for your very informative replies!

The greenhouse I was thinking of buying is this one:

http://www.greenhousepeople.co.uk/greenhouses/small-greenhouses/palram_greenline_6x8/

What do people think? It isn't twin walled polycarb, just single. There is a base included.

It's interesting to hear about your bad experience with polycarb, TortMad. Which polycarb greenhouse did you buy? Are they all the same or would some be better at keeping the rain out than others?

Paddy

 

"What do people think?"

1. 6' x 8' is very small. If that's all the space you have then fine, if its a budget issue (i.e. you have more space) then I recommend getting a bigger one. The smaller they are the harder they are to keep cool in the summer. This one is £290 - my 40' x 10' glass one cost £400 from eBay (although it is second hand, and I had to collect it)

2. "Please note that this IS a budget greenhouse.It has less metal in than other models, and it will not stand up to strong winds"

Unless you have a very sheltered site I reckon it will blow away :(

 

..also the weight of toughened glass will more than double the weight of the structure and make it more rigid. If a greenhouse is not secured to the ground it doesn't take much wind to set it moving. Remember, 80mph winds in this country are not uncommon

 

Personally I`d steer clear of the budget polycarb jobby.
1mm polycarb is thinner than the thickness of a cd so there`d be a very good chance of the panels flexing, bending and falling out.
Don`t forget that the heavier the greenhouse, the better the foundation needs to be to support it.

 

Hi all

Thanks for your helpful replies! It's all good, I haven't bought anything yet so this is all really useful info.

Kristen - it is a budget issue mainly, and also the fact that we live in a rented house and although the garden is quite big, we don't want to use it all for our veg growing as we'll have to replace turf, etc when we eventually move out.

Hex - re the weight of the greenhouse, I am planning to site it directly on the grass, so if it is very heavy will it 'sink'?? This seems like a silly question I know but I am a novice in these matters. As we live in a rented house, we can't do stuff like make a concrete foundation or anything like that, the most we could possibly do is get flagstones to put underneath it (but this would be more expense that we can't really afford).

It's all so complicated! :cnfs:

Paddy

 

Have you tried asking your landlord? When we rented a property our landlord was thrilled with the modifications we asked if we could make. I'm sure they aren't all like that though ...

 

Hiya,

No, haven't asked specifically about a greenhouse but we did ask about growing veg prior to moving in and she agreed to let us use 'part' of the garden. I suppose this could be interpreted in a number of ways! However if we have to move out in a year's time (possible) then the bigger the greenhouse, the more of a pain in the proverbial it would be to move...

I've just been reading Joy Larkcom's book and she mentions polytunnels, this is something that I hadn't thought about because I just assumed they were all massive, but I have seen some nice looking 8x10 ones online which are a fraction of the cost of an equivalent sized greenhouse.

What do people think about polytunnels? Are they worth it? Given budget constraints and the fact that we may have to up sticks and move again at the end of the year, it seems like a good idea...

Paddy

 

Yes I agree about having to move it when you leave; my comment was more in response to your "we don't want to use it all for our veg growing as we'll have to replace turf" - I figured that a Veg patch could be an asset to a rented property, for future tenants.

DiY Polytunnel