Keeping stuff alive in the arctic blasts

I put them in frost free conservatory stood in a gravel tray. Watered occasionally during the winter, but whatever ran through the pot would have been around their feet for the rest of the week I would guess. I have read to use pond baskets and stand in a tray of water. Sounds like a lot of wet to me, when day temperatures are chilly ... the ones I had in the border, watered now-and-again with the other plants near by, performed better than the ones I stood in the pond marginal ... so I'm not sure how wet they actually need it to be.

 

I'm going to treat mine like a houseplant during this winter and see what happens: I've moved it to the bathroom

 

I would like to do that but it's in a 12" plus clay pot that's been submerged in a pond all winter. Not that I'm house proud or anything, god forbid, but I'm wary of turning into the sort of crazy plant lady that shares the bath with her precious darlings.

 

Good job you can't see my house then ... particularly this Autumn as waiting for, delayed, rebuild of conservatory - particularly as it is on the site of the original!

 

Its much cheaper to provide artificial light to a dark warmer space than to heat a bright cold one.

We use an insulated outbuilding with minimal heating to keep it frost free - typically a 1kw fan heater on for half an hour in the middle of the night (low rate electricity) keeps it well above freezing even in the depths of the cold winters from a couple of years back. A low energy grow lamp on a timer over night kept everything looking good.

Heating a greenhouse costs so much more even with bubblewrap insulation etc.

 

I find it easy to keep my conservatory frost free. Its partly walls (which are insulated) so much less glass than a greenhouse, and its air tight too - no ill fitting windows like greenhouse vents! plus it has the benefit of heat-leakage from the house (well, maybe the is no leakage, just a relatively "warm wall" on that side). I typically heat the conservatory for less than 5 nights a year.

However, the light levels are rubbish (and spring of 2013 was a disaster, both for light and heat, so everything was late).

I also have grow lights for things I want to overwinter warmer than frost-free and/or to provide extra light. I 100% agree with Gaz that is a much better way to go, plus you get to do some "gardening" in the winter The Bugs love the artificial conditions of warmth and light though :(

 

So far, it's been so mild that everything is still in the greenhouse flowering. I have found that it takes until February for stuff to really start to deteriorate and suffer from downy mildew. I should get in there and chop stuff down to minimise that.

 

For many plants the biggest risk is the damp, trying to keep things on the dry side can help, but then you have the risk of RSM (red spider mite)

 

I agree with Gaz. Plants will overwinter, in a cool bedroom, with a surprisingly low level of light.

In my lightbox the light level is 10,000 lux. Coming from 3 three feet long fluorescent tubes over a single growbag tray. This is close to summer light levels, and will keep plants is active growth - its also heated.

In my third bedroom I have 7 growbag trays under 2 four feet long tubes, ie 80 watts (on a time switch). The light level is much less at only about 500 lux, but all the plants overwinter quite happily. A single tube (ie 40 watts) would probably be OK.

 

Luckily in my part of the world, very cold weather and low light conditions are unheard of but I have always wondered as to what the best artificial light source/s are for greenhouses.
I am assuming that both light intensity and UV content are crucial for the well being and growth of plants.

 

My thoughts are, if you just want to overwinter you dont need lights, just frost protection.
Its when you start trying to make things grow during the winter that you get problems.

Humidity being a real problem in greenhouses, causing rot, and high temps and lighting causing pests.
If the temps are low and the light is low, the chances of pest problems is reduced.

Equally if you dry out the root systems before cutting back and storing the chances of rot decrease.
Certain plants need to be dried of probably earlier than is supposed, for instance, I like to start drying out Erythrina in September, it ripens the wood, I do this by putting the pots on their sides, they dry out fast at that time of the year.
Brugs are much leafier, so can still dry out in October,
Its a matter of trial and error.

 

Pete - I will always remember the very good advice you gave about leaving greenery on Cannas to help them to dry out the compost, before cutting back. I did the exact opposite in my first year of growing them. I cut my topgrowth back and left the rhizomes in soaking compost. They just rotted. Actually, there is the wider point that you shouldn't leave anything that has lost its top growth in wet compost over the winter.

Most of my plants are continuing to grow at 10C in my garden room, and so can probably handle compost that is still wet. But I noticed that Erythrina (first year from seed) was one of the very few plants that has lost all its leaves. I will check tomorrow on how wet the compost is. Canna altensteinii also died back, probably because it was subjected to about -4C outside before my room was finished. So remembering your advice I recently (when all the green from the topgrowth had disappeared) repotted it in compost that was drier. But I noticed new growth from the rhizomes below ground level presumably due to its current temperature of 10C.

Dave - I suspect that the actual light source doesn't matter, it mainly comes down to cost, with fluorescent tubes, metal halide and LEDs all being contenders. I use fluorescent tubes, where the light is produced over a large area (tubes only consume about 10 watts per foot - thats due to the physics) this allows the plants to be put very close, because the heat generated is also spread out, so is good for cuttings and seedlings. Large plants need more powerful light sources to allow light to penetrate to the base so metal halides tend to be used. But they can get very hot and must be further away, which is less efficient. The new kid on the block is LEDs. They used to be very expensive to buy, but their cost is coming down and their efficiency is going up.

Light intensity is very important. For active growth, in combination with high temperatures, you need a lot of light. But to keep plants alive in a cold area over the winter you need much less.

 

Thanks for the info @PeterS
What about CFLs?
I would have thought that they would produce quite a good light intensity at low cost, but came across a study that found that the UV output was rather high and detrimental to some flora if in close proximity.
I will try and find that study and post a link to it.

 

Still not been able to find that study/report (serves me right for not bookmarking it straight away) but found these two sites.

The first is from wikipedia and has lots of info especially at the bottom of the page:
http://en.wikipedia.org/wiki/Compact_fluorescent_lamp

The second is mostly for vivariums but I suspect that some of the info will apply to greenhouses as well:
http://www.uvguide.co.uk/phototherapyphosphor-tests.htm

Hope I'm not derailing this thread or going off topic.