Annie Hope

I live 7km from the sea where frosts are frequent (down to -4C /25F) but snow is pretty much unknown.  

I am looking at building a Chinese style Greenhouse with a wooden frame.  I am not going to try and do a roll-up curtain on the outside, but will build inter-Greenhouses for the tropical plants if I need it.

Is there any reason why a basic lean-to with a straight sloping roof and straight walls is not as good a shape as any other?

Does steep roof pitch or slanting side walls really maximise sun exposure to plants  if the floor area is the same?  I can't logically see why they would.  They may maximise the ratio of sunlight to air inside the greenhouse by a little bit.    (I know that plastic sheedt left directly on plants can burn them within a hour, so there is some importance in this).  Because these will be used also as valuable living space, having adequate roof height is important. (our three bedroom house is 100m2 / 1000ft2 and we also use it as home office/factory for multiple buinrsses.)

EDIT
This is the suncharts for 100km away/  https://www.wgtn.ac.nz/architecture/centres/cbpr/resources/pdfs/wlg_sunpath.pdf
We also have an average max in our hotest month of 23C / 73F and the highest on record is 31C/81F, so sweet potato, eggplant, melons etc really need extra heat as well even in mid-summer.  One market garden even grows their sweetcorn in a tunnel house in summer!  The house already has a 1m overhang on the sunfacing side, that shades summer sun.   I am happy for the greenhouse to get full sun in summer and just vent out the excess.  

I was wondering if anyone has had success with a DIY insulation blanket.

I am interested in making a cheapo Chinese greenhouse, but the insulated blanket is the most difficult part.  Both making it and how to roll it - either with motor or by hand.

Has anyone had success without the blanet but with the "Greenhouse within a greenhouse" and some good thermal mass?

We have frequent frost but with a min of record of -4C (we are 7km from the sea).  
I also have a water table only 5 feet down, and it sits at 13C year round.   I have thought I could make a second well in the greenhouse, and pull water from that and use it to heat somehow.  

Douglas Alpenstock wrote:First, protect the hay. Good hay is precious, expensive, and hard to get. Other insulation is cheap and easy to get. My 2c.

  What insulation would you use?  I prefer not to use styrofoam.

I am wanting to use hay bales as greenhouse insulation, and also have them maintain quality to be used as stock feed if needed.  (I would have two greenhouses, one with hay I intend to use that year with my winter greens, and one with my 3 month emergency reserve that I hope to keep with insulation all winter with my heat-loving plants, but will sacrifice if needed.  I will alternate them each year.  Avery lows in winter at 2C and max low on record is -4C so plants pasture/lawn stays green even in winter here).

 I am looking at a  Chinese style greenhouse, with single row of straw at the front, and sides, but three or four rows high at the back.  
I see two concerns, humidity on the side of the walls, and moisture from below.  We are looking at building the frame anyway from pallets, and so I am thinking that having the hay a bit from the side and/or doubling lining the pallet frains with plastic inside and outside would help a lot with condensation.

I could put the hay on a raised bed of stones, but then this would allow the cold air through at ground level with the coldest frost, so again maybe covering the base of pallets on the ground with plastic and then filling them with wood shavings, (which we have a pile of).

I would like to avoid as much plastic as possible, but there seems little other good choice at this stage for greenhouses.  

Hi,  This is many years later, but did you try this?  Did it work?

I have some unhulled barley grain that has dead grain weevils in it.  (I put it in plastic buckets and froze it).

I have had great success in the past sterlising unhulled barley and growing on spawn, but the weevil addition is a new thing.

I have read about people adding a protein source to their spawn medium, but usually something like soya beans rather than weevils.

Anyone know how oyster mycelium will respond?  Will they break it down or will it be a source of food for competing molds / bacteria?

In New Zealand hardwood is not easy to find, and so mushrooms are often grown on sawdust pellets from pine sawdust.
https://www.mycologic.nz/growing-on-blocks

"Overseas books normally recommend hardwoods, however in New Zealand, pine fuel pellets are the most readily available and cheapest form of compressed sawdust, which many growers have success on."


I read somewhere else, but can't find now, that the heat process that forms the pellets deactivates the resins in the pine.  I have experimented with pellets a bit and got mycellium growing in jars of woodpellet sawdust.

So without being an expert, I think you could easily pressure cook a few jars/bags of wood chip and grow a variety of mushrooms for dinner.  If you have more woodchip than can be easily heated, then this will be more difficult.

There are oyster mushrooms that grow on pine, but they seem to be rare:
https://permies.com/t/36692/fungi-grown-pine
http://amateurmycology.com/?p=1164

"But I think generally you'd start the seeds around the equinox, and for non-roots, potentially transplant (or plant bought plants) before the average first frost?"


Thanks for the reply.  Are you writing this for the northern or southern hemisphere?  We are almost at the shortest day  (21st June).  The gardening tradition here is not to plant pumpkin and other frost sensitive plants till the end LAbour day (end of October) as frosts are very unlikely after that.  But highs of 13C or more are common mid winter as well as light frosts.  The average high in midsummer is 23C, we are very temperate here.

I am living in NZ where we have occasional frosts down to -3C, but also temperatures up to 14C during the day.

It is the shortest day in a week's time in the Southern Hemisphere.  What is it that triggers biennial vegetables to go to seed?  Is it cold weather or the shortening and then increasing days?  If I plant biennial seeds after 21st June 2025, will they not go to seed till spring 2026?  

The house in on piles that are about 40cm off the ground.  IT does have insulation in ceiling, under house and at least some external walls.  ((Definitely in the new section walls build 20ish years ago, not sure about the walls built 40ish years ago).