Illumination, required for photosynthesis.

learn more… | top users | synonyms

3
votes
2answers
62 views

What is light when it comes to plants?

I often see and hear people saying "this plant needs light". What is light? Just sunlight(direct and indirect) or what else? My room doesn't get a bit of sunlight, direct or indirect, but there is ...
0
votes
0answers
6 views

short-day facultative plant [migrated]

What happens biologically to a short-day facultative plant that is a few weeks into its short day (flowering) photo period and is suddenly given a 24 hour period of light? Does anything change ...
3
votes
1answer
28 views

How many watts should grow light supply per unit area of edible greens?

There are many lighting products with different rated power. What is the typical grow light intensity (power per unit area) for edible greens?
15
votes
5answers
22k views

Can plants have too much light, or do they need night/rest?

Because we live in southern Canada, in the late fall, my mother likes to take as much of her garden indoors as she can fit, for the winter. She usually brings in her potted palms, a few flowers, at ...
7
votes
1answer
425 views

What LED light should I choose for a specific PAR watt need?

I wish to design an LED lighting system suitable for growing plants in the absence of natural light. I do NOT wish to just buy available specialised horticultural LEDs - I want to build my own using ...
7
votes
3answers
78 views

Solar driven LEDs to offset electricity for mass growing in a basement

I want to grow vegetables in my basement year round. I live in zone 3b, in a rural area and I'd like to start selling produce as well as providing food for my family as well. Ideally, I'd like to ...
15
votes
5answers
16k views

What can I grow in a sealed office environment with no natural light or airflow?

Can ANY plant with green foliage survive in a sealed office environment with fluoroscent lighting from 8am to 5:30pm and air conditioning set at 20 C? For the remaining time, there is basically zero ...
6
votes
1answer
313 views

What is 'Etiolation'?

I saw a comment about Etiolation when talking about wintering plants. Etiolation is a big concern also, in warmer temps and short days. I've never seen that word before, it sounds like it's ...
10
votes
1answer
356 views

Why are my aloe leaves turning white and brown?

I have had this plant of aloe for years, and it has always given me great satisfaction. Easy to take care of, I had separated it into different pots but now decided to keep it all together into a ...
2
votes
1answer
37 views

Does anyone have some references on using metal halide lamps in a greenhouse?

I am looking for some references to use metal halide lamp in a greenhouse. What specifications should I look for in a lamp?
7
votes
3answers
195 views

Is sunlight from my window enough to grow cherry tomato seedlings indoors?

It is my first time planting anything from seeds, and certainly my first time with cherry tomatoes. I've watched many tutorials and read many articles, so I have a fair knowledge about the subject. ...
6
votes
1answer
61 views

Help determine lighting requirements for wintering small plants indoors

I live in zone8. I have a few plants I've been experimenting with. I broke a few stems off a friends tropical flowering plant they got at Home Depot, and have been propagating them successfully, but ...
18
votes
2answers
40k views

Are household LED bulbs suitable as supplemental light for plants?

I live at a fairly northerly latitude where we have limited hours of daylight during the winter. Low-wattage (5-8W) white LED bulbs seem to be becoming more common as a household light source. Do ...
12
votes
7answers
24k views

How much lighting do I need for growing lettuce using indoor hydroponics?

I am beginning to get into indoor hydroponics to grow lettuce, I haven't figured out which type of lettuce to grow yet, I am thinking of a butterhead. I have been to many hydroponics stores and seen ...
2
votes
1answer
52 views

Upper limit on light intensity?

What is the upper limit on the light intensity for growing plants indoor in a hydroponic system? Except my electricity bill off course :-) e.g. Are 1000W HPS light per sq.m. ok, as long you can keep ...
1
vote
1answer
88 views

Replacement for an F15T8NDL 18" lightbulb

I am currently using an F15T8NDL 18" lightbulb for my plants in a light fixture, and would like to replace it with something much brighter. So my question is that if I add a higher powered bulb in the ...
3
votes
2answers
728 views

What plants survive in a relatively dark room?

What can I plant in a pot that will survive in a relatively dark room?
2
votes
1answer
314 views

Will solar lights around my vegetables and flowers be bad for them?

I have a decent size vegetable garden and various annual flowers in my back yard. I recently bought some solar lights and put it around the plants. The lights stays on all night long, and I wonder is ...
3
votes
1answer
80 views

Full-spectrum fluorescent light on hot pepper seedlings

I'm new to starting TAM Mild Jalapeno peppers from seed; this is my first time ever starting any peppers from seed. I was lent a full-spectrum fluorescent light yesterday, and I now have it turned on ...
4
votes
1answer
674 views

Am I meeting the light requirements for indoor dwarf citrus trees?

I've recently purchased 3 dwarf citrus trees that we plan to keep indoors for ~9 months of the year. We are in zone 6 so we can only reliably move the trees to the porch for June, July and August with ...
6
votes
1answer
139 views

Is total darkness acceptable for tomatoes to recover from transplant shock?

After re-potting tomato seedlings from plugs to larger pots (that they'll live in for about a month before they go out in the garden) it is recommended to let the plants recover from transplanting by ...
6
votes
2answers
622 views

Why is my apple seedling shriveling up after like 15 min, every time I remove the plastic dome?

Around 7-9 weeks ago (maybe more) I planted a sprouted apple seed in a cup of potting soil that I placed on top of a low heat pad, and covered it with a plastic bag. I also have a full spectrum ...
6
votes
3answers
666 views

What fluorescent bulb is best for my tomato seedlings?

It has been suggested that my seedlings may not be getting enough light. What are the best types of fluorescent lights to get? I have a single bulb, and looking to get another light or two to add to ...
6
votes
3answers
7k views

Glass vs plastic greenhouse covering: pros and cons

When building or buying a greenhouse, it seems to me that the material to use is one of the first concerns. The two options I'm trying to compare right now are glass and plastic films. The ...
4
votes
2answers
159 views

Is a skylight enough light for tomato seedlings?

I have a 2' x 4' domed skylight on a pitched roof, facing southeast. If I build a shelf so the seedlings sit a foot under this dome, will it be enough light to prevent leggy plants?
4
votes
2answers
442 views

How will indirect sunlight affect indoor tomatoes under grow lights?

I'm deciding where to put my indoor vegetable garden for the winter. I will use grow lights as the primary light source but part of my decision decision is based on the value of indirect sunlight. ...
5
votes
1answer
199 views

Can strawberries be grown year-round indoors?

Are there particular varieties that are best suited for indoor growing? Will the plant die after producing fruit after x amount of harvests? Are particular lighting schedules required to produce ...
7
votes
1answer
161 views

Which of These Bonsais Are The Most Appropriate For My Climate?

I want to buy a bonsai tree. The options are Ficus, Ligustrum, Carmona, and Sageretia. Reading the instructions on those links, I was convinced that I should get either Carmona or Sageretia ...
2
votes
2answers
277 views

Which of these palms would be easier to take care of in an indoor 9" pot?

I'm looking to buy a new palm to keep indoors in a 9-10 pot. I've narrowed my selection down to two palms, I'm wondering which would be easier to take care of between the 2 plants: Cateracterum ...
3
votes
3answers
608 views

Will this 20,000k LED bulb function as a grow light?

I see a 20,000k (color temperature) 12 watt LED E27 bulb designed for coral, aquariums and such. 7000k is supposed to be full-spectrum light, I hear. So, I imagine a 20,000k would be even more full-...
2
votes
1answer
83 views

Optimal temperatures and light times for pepper plants

Day/night temperatures? How much light is too much? Right now I have an indoor pepper plant that is usually 80-90F during the day with 18 hours of light. I'm pretty sure I'm overdoing it as the ...
3
votes
2answers
80 views

Tropical Growth Room for Vanilla Planfolia

I live in London and am designing a growth room in my garage (1m (W) by 1m (L) by 2m (H)), for a vanilla planfolia orchid. There will be one or two, and I am wondering how many of what wattage growth ...
2
votes
1answer
196 views

What is the optimal LED wattage for a single bell pepper plant?

I plan on topping it to keep the canopy wide. I am most concerned with getting an LED fixture that doesn't fully activate photosynthesis. Granted I know that wattage isn't the best way to determine ...
4
votes
1answer
347 views

Does a luxmeter provide an accurate measurement of usable light?

Does a luxmeter provide an accurate measurement of usable light? What values constitute equivalents of 'shade', 'part sun/shade', 'full sun', etc?
5
votes
1answer
181 views

What should I look for when selecting lights for indoor cacti?

We grow cacti indoors due to the weather (UK). What should we look for when selecting lights? We have had mixed results with a new lighting system and have started to lose some. See one of the old ...
5
votes
1answer
1k views

What is the best light spectrum for growing chili peppers?

Natural light is best for plants during all growth phases, but I'll be growing indoors, It's a good idea to have a basic understanding of the light spectrum and how it affects plant growth, in order ...
5
votes
2answers
894 views

What are the alternatives to AeroGarden

I'm looking for an indoor hydroponic system and I've found the AeroGarden family which looks great but I'd like to check the alternatives. Are there systems similar to this? Important features for me: ...
28
votes
4answers
8k views

Can aloe be grown indoors with artificial light?

I came across a very beautiful aloe in a shop a few days ago, which I would like to plant in my office next to my computer. However, there is no natural light (sunlight) and only fluorescent light, ...
8
votes
2answers
3k views

What is the effect of streetlights on plants?

This may be totally off the wall, but the sunflowers growing around my garden are bigger the nearer they are to the street light. I've seen documentaries with marijuana labs in California where they ...
2
votes
1answer
47 views

How to be safely install light bulb for outdoor vegetable?

My patio does not have direct sunlight, but I want to build a hydroponic system. The vegetable that I want to plant requires a lot of light, so I also want to put lighting system outdoor for the ...
1
vote
0answers
41 views

Photometry and plant growth [closed]

What unit of photometry is used to assess plant growth? Is there a catalog that lists plants and the required light exposure? I'm looking at more detailed indicators than "a lot of light" or "not too ...
4
votes
2answers
112 views

Comparison of efficiency of different light colors / spectrums

I am building an led light for my indoor hydroponic / aeroponic / foggaponic hybrid herb garden. I am currently using a 100W warm white LED module. It works fine but I am also building another RGB ...
6
votes
2answers
752 views

Is a full spectrum 380-840nm white phosphor LED suitable for growing plants?

I am an avid grower and like most I have spent much time and money on various lights and techniques. Take a look at this http://www.alibaba.com/product-gs/1519924202/High_lumen_phospher_100w_380_840nm....
4
votes
2answers
132 views

Is light direction or proximity more important when considering indoor natural light for plants?

I'm trying to provide my houseplants with as much natural light as possible inside my 2nd floor apartment. I have 2 large bay windows that face north, and can put my plants directly by the window/on ...
3
votes
2answers
664 views

What would grow well under a trampoline?

We have a trampoline in our garden where the trampoline itself is made from a dark mesh material that lets through light. This means that the lawn underneath grows fine (perhaps a bit slower?). So I ...
5
votes
1answer
229 views

Is High-Intensity Discharge (HID) lighting better overall than Compact Fluoresent Lighting (CFL)?

For hydroponic horticulture are Metal Halide (MH) and High-Pressure Sodium (HPS) lights still the staple/better choice for growing indoors or do Compact Fluoresent lights (CFL) offer enough light ...
8
votes
1answer
2k views

What light cycle should I use to grow herbs indoors?

I would like to have a small container herb garden indoors this winter, but I want to make sure my herbs do not try to flower. Currently, it's a couple of different basil plants and some rosemary, ...
5
votes
1answer
2k views

What kind of light is needed for moss and ferns?

I'm planning to set up a nano-vivarium to grow moss and ferns indoor like shown in the picture below. My question is what kind of light is best or which lamps should I use? I don't have any ...
15
votes
2answers
587 views

What kind of a grow lamp can I use in my apartment?

Can anyone recommend a style of small-sized grow lamp that I can use inside my apartment to give my plants some extra light in the evening that won't cost a lot of money to run.
3
votes
3answers
356 views

How to soften water to water plants?

I am living in Tartu where the water is middle hard. I think that it is partially the reason why some of my plants are dying. I manage my plants by watering once a week by room temperature, 20C, ...