Best wattage for succulents and cactuses

[darth1211]

Hello, I have a few cactuses and succulents, and I can't seem to find what wattage they need. I am trying to find a lamp for them. Dont want linear LED battens. The plants are facing east, and people say that's a bad side for indirect sunlight. So I've been recommended to buy a grow light, but can't find one with the right wattage they need. Thank you!

[zpeckler]

I've been using some Spider Farmer grow lights for cactus seedlings for two years now. I know you said you didn't want LEDs, but I can't recommend Spider highly enough. Having the dimmer switch makes them incredibly useful for getting your seedlings acclimated to brighter light, and at max they're plenty bright to grow adult cacti under. They are a little on the pricy side, but you get what you pay for.

[darth1211]

I've been using some Spider Farmer grow lights for cactus seedlings for two years now. I know you said you didn't want LEDs, but I can't recommend Spider highly enough. Having the dimmer switch makes them incredibly useful for getting your seedlings acclimated to brighter light, and at max they're plenty bright to grow adult cacti under. They are a little on the pricy side, but you get what you pay for.

I've seen Spider Farmer's grow lights, but I don't have a canopy to hang the lights on. The plants are on my windowsill.

[zpeckler]

I've seen Spider Farmer's grow lights, but I don't have a canopy to hang the lights on. The plants are on my windowsill.

Ah, gotcha. Well, no need for anything particularly fancy. I just stuck together some 3/4" PVC I had lying around to hang my lights from.

[darth1211]

I've seen Spider Farmer's grow lights, but I don't have a canopy to hang the lights on. The plants are on my windowsill.

Ah, gotcha. Well, no need for anything particularly fancy. I just stuck together some 3/4" PVC I had lying around to hang my lights from.

Would 60 watts work?

[ohugal]

It all depends on the light output of the lamp. I think either you buy a (high quality) growlight which comes with sufficient information on how to position in accordance to your plants. Or you get yourself a (proper) measuring instrument like a Lux or PAR meter with which you measure the PPFD (PAR Photon Flux Density) or FC (foot candles) of your light source. Usually a specialized growlight comes with a chart on how to position the light source in accordance to the 'crop'. It's tempting to immediately buy a lamp, but here's some documentation which might help you in your quest:
https://www.houseplantjournal.com/brigh ... -by-plant/
https://herebutnot.com/light-recommenda ... useplants/
https://gpnmag.com/article/dli-requirements/
https://growlightmeter.com/light-requir ... or-plants/
https://www.horti-growlight.com/en-gb/t ... s-per-crop
https://happyhydrofarm.com/plant-dli-ch ... -dli-chart

@Zpeckler: what is the output you use for your seedlings? There is not a lot of information on that. 100/150 umol/m2/s?

[zpeckler]

@Zpeckler: what is the output you use for your seedlings? There is not a lot of information on that. 100/150 umol/m2/s?

The main light I have is the Spider Farmer SF 2000. The manufacturer says it has a PPE of 2.7umol/J and a PPF of 527umol/S, and it came with maps of photon intensity at different hanging heights. I don't know what the overall intensity as a function of area, though.

I us a lux meter ap on my phone to get "relative" light intensity measurements. I can't vouch for the app's accuracy, but it does seem to be precise and its measurements are very repeatable. I started out with the grow light set to deliver 10,000 lux to the put lucky enough to be directly under the center, and just recently increased it to 12,000 now that my seedlings are all about 6 months old. I'll keep slowly increasing it through the fall and winter.

Just to put the 10k reading in perspective, it's about 1,500 lux under the overcast skies were getting right now from Hurricane Hilary, full sunlight at noon is over 100k, and my cacti under my 30% shade cloth get about 50-60k.

[ohugal]

Cool, thanks for the info!
The fact your lamp is dimmable makes it very versatile. You use the dimmer?
I have yet to install my lamps, but they are full spectrum such as yours and the wavelengths are similar.
I can't really follow with the "k" you are refering to. You are talking about color temperature? You measure that with your phone?

[jerrytheplater]

10,000 lux = 10k, (not degrees Kelvin color temp.)

Full sun is 100k or 100,000 lux.

k = kilo

[zpeckler]

Yeah, sorry... Unclear. Jerry is right, I meant 10,000 lux, 100,000 lux, and 50,000-60,000 lux, respectively. I don't know what overall color temp the light puts out, but the spec sheet says the LED panel has various different diodes that put out light at 660-665nm, 3000K, 5000K, and 760nm.

Modern smartphones have a light sensor so they can auto-dim or brighten their screens to keep them visible at varying ambient light levels. Apps can use that built-in hardware to show you what light intensity is falling on the phone. I downloaded one called "Lux" for my android phone.

The dimmer feature was why I bought it basically. I can grow my seedlings under the light and just turn the knob up over time to slowly get them used to brighter light over time.

[7george]

You have to find the right light spec. by trying different setups and looking at the seedlings reaction. From those above I would choose 5000K and play with distance to those seedlings to adjust the right one.

[leisurely]

I found twenty packs of seed in a drawer that i collected from different plants in 2015. Would it be possible to get any germination or would it be all in vain?

[jerrytheplater]

I found twenty packs of seed in a drawer that i collected from different plants in 2015. Would it be possible to get any germination or would it be all in vain?

Best I can say is try them all and see. What do you have to lose? I have germinated 7 year old Ferocactus seeds easily. Others won't last that long. You don't give any ID of what you have.

[Aiko]

Probably depends a bit on the genera. Melocactus will certainly germinate well enough still. And I bet the cryptocarpic Mammillarias too.

But even if they are Fraileas, which apparently lose viability fast, I would still give the seeds a try.

[leisurely]

The seed are from Mams., Discos., Melos., and Frailea asteroides. Thinking of putting them all in a shallow pan divided by sticks or straws.