South African Bulbs 2015

[Maggi Young]

Sorry David. A serious senior moment. Why on earth did I type Romulea? when I meant Lachenalia? I don't even have any Romulea

Erle
Anglesey

No worries, Erle, I've edited your post for you. I am pretty good at thinking one thing and typing another myself!

[David Nicholson]

No worries, Erle, I've edited your post for you. I am pretty good at thinking one thing and typing another myself!

Moi aussi

[ArnoldT]

Steve:

I've been using a HID mercury vapor bulb for years over some of the South African bulbs.

The LED"S are out there but cost can range 200-300 dollars per bulb. 

I would have tired one bulb the fixture housing the bulb would have to be changed.  The LED's don't require the ballast needed  for an HID.

[Rimmer de Vries]

I use 54 watt T-5 fixtures to grow all my winter bulbs and they work wonderfully but they are not cheep fixtures or very cheep to run but much less cost than the old type of grow lamps and put out much stronger light than the typical T-8 or T-12 fluorescent shop lamps. These fixtures with bulbs can cost $100 to $200 depending the number of bulbs, there is always a sale somewhere.  This solution was much cheeper than installing a greenhouse and does not need supplemental heating in our sub Arctic winters down to -30ºC

These fixtures have two switches so you can choose the outer 4 lamps and/or the inner 2 or 4 lamps and have an extra outlet so you can daisy chain fixtures or plug in a fan.  because they give off heat (just like the sun) i use 6" fans on the same timer to cool off the grow space and stiffen up the stems.  the first year i ran these fixtures with all the light bulbs on, but this year i have mostly used the outer 4 light bulbs and turned on the extra light bulbs when i see flower stems popping up.

the fixtures come with 6400K 54watt T-5 light tubes but you can use 24watt  and get other light band widths.   the 6400k work well for flowering plants. 

The plants grow wonderfully but some plants not used to the bright light get scorched and others need the full light. so plant positions need to be sorted out.   for the coolest growing south African bulbs i have the pots and trays on the basement floor in a sand plunge with the light about 2.75 feet above the floor.  this areas is typically below 50ºF at night and gets to the 60sºF when the lamps are on with the fans.  other ZA plants the South Americans that do not need the cold below 60ºF are located on a table, shelf etc.  with the lights at varying distances from the plants.

I have tried the screw socket style blue and red LED grow light sold on eBay from China that have dozens of tiny LEDs and the plants seem to grow tight but some plant leaves turn black under this light.  these LEDs are not supposed to give IR but i wonder?  it is hard to see things in the red and blue light.

here some photos of the set up and some plants grown exclusively under these lights.

the last photo shows two T-5 fixtures and a shop light on top for lily seedlings

[SJW]

Arnold/Rimmer - thanks for sharing your experiences of using fluoros and HIDs. Indoor growing under lights seems to be much more popular in the States than in the UK, thereagain we don't have to cope with such extreme winter temperatures! As you say, the various types of fluorescent lamps are much cheaper to run than halides/sodium lights and LEDs would be even more cost efficient (I'm starting to replace my house halogen downlighters with LEDS). As I suspected though, it's the start-up costs of an LED set-up that's the killer at the moment. Perhaps as they become more popular the prices may start to fall? They run much cooler than flouros and HIDs of course which is a bonus. 

[ArnoldT]

Steve, prices will drop.  I purchased some small LEDS to replace halogen lights in a stove hood for $5.00 each today.

[Pete Clarke]

I'm not sure what is the current correct name, Lapeirousia, Fressia or Anomatheca, but here is the blue for of laxa.

[Matt T]

Freesia caryophyllacea (syn. F. xanthospila) - picked these up at Dunblane last year as bulbils submitted to the seed exchange. Gorgeous scent.

[Paul Cumbleton]

I know from past comments that some of you may be looking for Eucomis schijffi. I have some 3 year old bulbs available on eBay currently - see http://ebay.eu/1b9Lks4

Flowering for me for the first time is Lapeirousia silenoides. I love the intense colour!

Paul

[ArnoldT]

Lachenalia aloides quadricolor an immature flower.
Lachenalia vanzyliae
Unknown Lachenalia growing in someone else's pot.

[Paul Cumbleton]

Returning to the subject of LED & other forms of lighting, I hope it will be useful to point out a large misunderstanding that has persisted for a long time. This is the belief that alpines and other plants grow more compactly in the wild than they often do in cultivation due to being exposed to higher levels of UV radiation. This is actually not true. In his bulb log last November http://www.srgc.org.uk/logs/logdir/2014Nov121415787177BULB_LOG_4614.pdf Ian showed the new LED system that Gothenburg is trialling and said that they were "high in UV" for healthy growth. If you check the spectrum of the lamps used on the company's website, you will see that actually these lamps cover the range of 400nm to 735nm  - which encompasses the photosynthetic spectrum but not the UV. In fact these lamps don't give out any UV light at all.

Science does not yet fully understand all the ins and outs of the specific effects of various wavelengths of light on growth, but experiments on alpines have shown that levels of UV light do not affect the stature of the plants. In fact, like most things, UV can damage plant tissue just as it can damage your skin if you stay out in the sun too long. Experiments show that most plants actually reflect the majority of UV light that falls on them in order to protect themselves from damage. And the experiments also show that of all groups tested, Alpines reflect the most UV (more than 90%).

As well as experiments, observations in the wild also point to the fallacy of the idea that it is the UV keeping plants compact. For example, many arctic and sub Antarctic plants inhabit misty coastal ranges where they receive very little UV and yet they are extremely stunted and dwarfed. Also, if UV intensity had a significant effect, you would expect to see latitudinal gradients in the stature of alpine plants, but this does not occur.

So what does keep alpines dwarf and compact? While the full story may not yet be in, the evidence all points to LOW TEMPERATURE as the key factor. Our alpines in cultivation grow out of character largely because we cannot keep them cool enough. It is also known that the overall intensity of light (of all the useful wavelengths, but not UV) has a part to play at least for some species.

For those who would like to know the references and read more about this, the best place to start is the discussion about all this on pages 114 to 119 of the book "Alpine Plant Life - Functional Plant Ecology of High Mountain Ecosystems" (second edition) by Christian Korner ISBN 3-540-00347-0

Paul

[Matt T]

Can someone remind me, Freesia (and maybe other bulbs) are sensitive/don't require one of the major plant nutrients. Is is phosphate? And will it kill, or just ail the plants?

[Maggi Young]

I'll copy your post to the Bulb Log thread, Paul.
It all begs the question - what then are Gothenburg using the lights for, if there is no effect  re UV, as supposed ? 

[ArnoldT]

Maggi

Sometimes "experts" try things to prove they don't work.

[Maggi Young]

Yes, I know that, Arnold , but  Ian's impression was that it was the higher levels of all  the spectrum of light, including UV,  that was the point of these  lights.  Either he got the wrong end of the stick as regards the description he was given, or he and the GBG folks are all labouring under a misapprehension!