fertilize plants under light or in the dark?

[dieselplower]

I was wondering if it is better to fertilize floating plants such as water hyacinth at night when it is dark, or, during the day, under light? I have a separate tub i use to soak them in and i have been doing it at night, in the dark. I got to wondering if that isnt a good time to do it? Any maybe under light during the day would be better?

 

[Ruben Miranda]

Hello
Under light is always best.
Under light is when it will grow and use the fert.
Ok you say during the day so I will take that as you are doing this outside and when you say light you are meaning sun light right.

If it is inside a grow light would be a better method then light from the window and better to control time wise.
Water plants as I have read need at least 4 to 6 hours of sun light to do well.

Ruben

 

[Waterbug]

It doesn't matter. The uptake of nutrients and light are unrelated. Light is only needed to produce sugars. Nutrients are used to build cells which the plant does in light or dark. And besides, normally there are plenty of nutrients. When you add nutrients it would be extremely rare for all those nutrients to be consumed in a couple of hours. Adding nutrients is normally more like topping off a gas tank...they'll get used when and if the plant ever needs them, day or night.

 

[dieselplower]

Thanks guys.
Waterbug, i feel like they do need extra fert as they have been slowly dying off. I have light on them 12 hours a day. Sometimes more.

 

[Ruben Miranda]

Hello
Have you taken in to account the temp of water and out side temp
hyacinth like most water plants go dormant in the winter or cold weather.
So if these plants are not in a green house or the warm home under a grow light it is very unlikly that they will grow back
No matter how much fert or sun they get.

I see you are in Michigan it got to be getting pretty cold there now. ?

Ruben

 

[dieselplower]

Sorry, i forgot to clarify that i have these plants inside now. They were in my pond but now they are in a 75 gal with goldfish. I have 2 light bulbs over it.

 

[Waterbug]

Waterbug, i feel like they do need extra fert as they have been slowly dying off. I have light on them 12 hours a day. Sometimes more.

I'm more of a test type person.

On the list of things that will kill plants not enough fertilizer is pretty far down the list, very close to the bottom. Lack of fertilizer is normally associated with slower growth, not as much growth as desired, weak growth, etc. But actual death...nope. At least by experienced gardeners.

For pond type plants you'd need a tremendous amount of artificial light and probably heated water. Way, way more than a couple of bulbs if you wanted actual growth. And the lights have to be very close to the plant, almost touching it. And reflectors to get light hitting more of the plant. And the lights would probably have to run 24/7. To our eyes it may appear that a couple of bulbs are pretty close to daylight, but if you put a meter on it you'll see it isn't. Plus the human brain changes our perception of light so we are very poor judges of light intensity or even spectrum.

Next is temp. Most pond plants can survive low temps at night as long as day temps are high. Cool water and cool air coupled with very low light and the plant sees winter coming and starts shutting down. Many pond plants store energy in roots, rhizome, etc., and want to move energy out of the plant and into storage before a frost comes. Your plants may not be dying, might just be shutting down. Once the shutdown happens it can be very difficult to trick it back into growing.

 

[dieselplower]

Ok thanks Waterbug. I keep the house at 68* and the lights are about 8" above the plants.

 

[Ruben Miranda]

Hello

Deisel wrote:

I keep the house at 68* and the lights are about 8" above the plants.

68 is not warm enough try to think in terms of spring temps 75 80 even plus the plants want warmer water
outside temps do's not equate to water temps. You should also check the water temps.

You say light bulbs are these house hold light bulbs or are they Grow light bulbs there is a big difference.
Reg bulbs won't do nothing for a plant.
And also what are there wattage
As a example: A planted fish tank you want a minuim 2 watts per gallon 3 is preferred but since these plants are floating
I would think that half of that wattage would do.

Ruben M.

 

[dieselplower]

Great info. Thanks. I have a mix of cfl and old school light bulbs. Ill be sure to find some grow lights asap.
Clearly i know nothing about this!

 

[gardengimp]

When I grow my veggie starts in the garage, I use 4 2 tube fluorescent lamp fixtures. They are on chains, so I can raise them easily. I keep the bulbs less than 1/4" from the seedlings. Still not enough light for optimal growth.

 

[Waterbug]

Yes, you have to consider beyond air temp. A plant sitting outside in the sun is going to be very warm compared to just the air temp because the surface of the plant heats up. Just like when we stand in the sun. The air temp isn't different in sun vs shade, it's the sunlight hitting the surfaces that causes a lot more heating.

You might want to check out some indoor growing web sites to get a better of idea of what's needed. Google "indoor marijuana growing" for the best source of info. No matter your opinion on marijuana, you can't beat the understanding those growers have for growing plants outdoor plants indoors.

I think you'd be wasting your money buying a couple of grow bulbs because that's still way, way less than you'd need for actual growth. And they're pretty expensive.