Kitchen Garden Forum

I expect like everyone else I am anxious to get going for spring but my spare room (propagating area)has little natural light so my seedlings invariably go leggy and I have to move quickly to pot on.Has anyone any experience in grow-lights,(home made if poss,)to give more light and if so what wattage per area and what colour temperature (blue daylight maybe?Thanks in advance,Ferret.

They were discussed on Radio 4's gardening programme today I'm sure you will be able to listen on line I was not really giving the programme my undivided attention but I think they got the thumbs up

Yes, Bob Flowerdew said they were a good idea but didn't offer any advice on how to make your own. Only just suggested to buy one. I tried placing foil covered pieces of cardboard to help catch the sun last year. Can't say I could tell if it made a difference as it was my first year ever trying all of this gardening business. I used the method for propogating lavender in February though and got several health plants at the end of it all.

Tara

I tried one of those "Whitefire" florescent growlights out last year. Can't be sure that it works, but I got earlier tomatoes than my neighbours ...

I have heard it said that ordinary florescent lights will work OK - though they probably aren't as efficient.

As you can tell by eye, green is the part of the spectrum that plants can't use. The near IR doesn't get absorbed either, and I guess low color temperature (eg filament lamp) sources waste a fair bit of energy in that region.

As an aside, I read in a nursery trade mag once that plants are sensitive to green light, which encorages upward growth (think competition). A trick to get stocky plants was to use light filtered to be slightly magenta, ie, weak in the green areas of the spectrum. No, I haven't tried it !

Oh dear, I put a great answer to this one a couple of years ago, but I can't find it doing a search now. I can't even remember what I called myself..it's an age thing they say.
Here goes:

You can provide artificial light for plants, but unfortunately you need an enormous amount of light to have any effect and people do have a job in believing this.

Ordinary flourescent lights are the best things to use for amateurs. They need to be held no more than 9 inches...see how old I am...from the growing tip to provide sufficient light intensity to stop the plant becoming etiolated. Therefore you need to support them on some sort of suspension that you can raise as the plant grows. Baler twine for instance. or suchlike. A reflector built of hardboard and covered with kitchen foil helps the light intensity. Also, because the light is so close, there is the added benefit of warmth from the tubes. You need at least 12 hours of light per day.
With a typical 4ft tube you will be able to light an area of 6 or so square feet adequately.

Even using flourescent lights, the power consumption is pretty gross, and it is best to run them at night on off peak electricity. Do warn the neighbours....

You will also need to make sure that the setup is electrically safe, as there is going to be a considerable amount of wiring present.

Commercially, it is done with metal halide or high pressure sodium lamps and only with high value plants and crops.

This does work, and we have been very successful with this setup, but you do have to be something of an experimentalist to set it up.

I do remember Johnboy concurring with the need for an unbelievable amount of light, I think he probably did something similar in the past.

Do have a go, it's great fun, but if you don't get enough light you will be dissapointed.

anyone had any experience of the low energy growlights that have come on to the market in the last year or so? I have a 600 watt sodium lamp, but its far from ideal, its bulky because of the accompanying ballast (starting gear) and apparently the lamps deteriate after a few years so having had mine 7 years now i'm not sure how much good its doing. Plus at its best it only provided good growing light for about a metre square..Paul.

You can use Osram Floura or Biolux flourescent tubes, which give a better light spectrum for plants. However, they are quite difficult to get hold of, you have to buy them new and they are expensive. Whereas it is fairly easy to come by ordinary secondhand flourescent light units. Also the light output is lower than a normal flourescent tube, so I would think they are only of benefit to a commercial grower.

P.S..You did mean a 60 W Sodium lamp I guess not 600W.
PPS. I am not sure that the orange light spectrum of Sodium lamp, assuming it to be of the non high pressure type, is any good for plants is it?

Its a six hundred watt "planta" sodium lamp with enhanced blue white light spectrum. other similar are Agro & Growlux. It used to be that the Sodium (son. t) gave orange red spectrum recomended for flowering subjects. or for blue spectrum (needed for leaf growth) metal halide lamps were recomended. The later sodium lamps are alledgedly the best. With the 600 watt giving the most lummens per unit of energy used.92,000 what ever that means!
My query however was concerning the new low energy cold lamps normally comming in 125 watt and 200 watt. They are self ballsting and come either in blue/green light or orange /red. I was just wondering if anyone had any experience of these as they are relatively new. rgds Paul.

Sorry forgot to add that, yes it is a high pressure lamp.Paul.

AAAAAAgh. My lamp is high pressure not the ones I'm enquiring about...... Its old age you know!