I have a couple of big san pedros that are growing really fast, problem is that they are getting pretty skinny at the top now and still want to get taller.


I have them growing under 250w of of various flouros and le´s, both warmwhite and cold white.

Im thinking about putting something on top of them so they cant grow aymore i height but that might be bad for them.

Any ideas?

Skinny growth is usually related to lack of light (the plant invests energies in getting closer to the light source) so if you want to change that I would try and give them some full sunlight. If it's not that, it might be wrong feeding, or overcrowding in the pot.

In any case, once they get too tall, why not just take a cutting and root it in a new pot?

moar sunlight, not bulbs imo

Mine get skinny like that when they don't get enough light. I try to get them into direct sunlight for at least a few hours a day this time of year. In the winter, I bring them in with no supplemental light and no water and they just go dormant.

Yep, just slice off those skinny bits and replant em. Maybe try a lateral log style, more chance for more pups I think, always looked really cool to me

You could consider a smaller pot too, just cut off some of the roots and repot. I'm starting to think I'm going to try and time my grows so that regrowth is in the winter and won't need as much light to get all that tall, then the full sun of summer to fatten up and take off.

Happy growin!

D

We dont get much sun here and even when we do not much of it reaches my windows...

I guess i could get another 100w or so in there and maybe moar reflectors.

Right now i have 3x 30w warmwhite t8 tubes, 4x 18w cool white t8 tubes, and a bunch of le bulbs with reflectors.

Where are you that you don't get a lot of light? Maybe get creative and build some garden boxes, you can tack em to the side of your house where there is sun? These grow so easy, if you can just get em in the sun, theyll do great.

Fluorescents have a good spectrum but low potency. Since they are low in heat emission as well, you may also consider bringing them as close to the cacti as possible, four or five inches. Light decreases proportionally to the square of the distance, a foot of difference can deliver pretty different results.

Before investing in more light equipment, you also might try to place one cactus in the spot you have with the strongest natural light, even if normally it's not sunny, and see how it does.

Well first of i live in a appartment with only one window facing the sun, ad on that side i have aother building blocin the sun most of the day.

I actually have one of my 20cm san pedros living there ad it seems to gro in about the same rate as the ones in the closet.

I guess i could try to put one of the big ones there and see how it does too.


For my grow space i use a walk in closet which has a space of about 110x110cm where all the cacti live.

i have mounted the Flouro tubes on the walls so they get blated from all directions and then i have built a roof of reflectors that i can adjust height on depending on how high the cacti are, its this roof that is getting close to its limit.

In this reflectoe roof i have abunch of le bulbs aswell.

Any chance you can get on the roof or maybe a neighbor with a deck? What state are you in? Warm enough year round to plant a few in the surrounding hills?

I dont know how many times i need to repeat this but no i cant have them outside, i live in the middle of a big city and would never trust to have them outside since they would get stolen or vandalised quickly,

Anyway i did find a few 12w LED spotlights at work which i have now installed, they were at 3000k so not optimal but still thats a little more light i guess.


I think i have made the best i can with the surface i have with a big mylar blanket covering the entrance and reflector roofs to reflect back as much light as possible.

When i get more money i will probably get a few more cold white flouro tubes and maybe one or two of these LE grow lights that some people use for ganja..

Anyway about spectrum? is warmwhite flouros totally useless or is it just that cold white is prefered? cause now i have some mixmatched but if cold white is alot better i guess i could replace my warmwhite tubes to optimise the lighting as much as i can?

With full grown cacti you should aim for full spectrum light. You can achieve that reasonably with CFLs or metal halide lights, just making sure that the combined spectrum of the lamps you have agrees with that.

I wouldn't rely much in LEDs though. They can provide a fair intensity in lumens (as long as the individual LED lamps in the fixture are at least 1W each, otherwise they will hardly make any difference) but they usually have a very narrow spectrum and that is suboptimal. I have used in the past a UFO LED type of fixture (with blue, orange and red lamps) for a couple cannabis plants and it worked fine, since the lamps were specially thought for cannabis flowering, but other plants did not like it much.

I will check out what a Mh lamp could cost used, aiming to get a 250w or so, that would probably be a nice boost of light to my cactis, is the spectrum of these better than the LE lamps designed for growing?

Something like this

http://odlingsbutiken.se...lag-energi-200w-bla.html


compared to this?


http://odlingsbutiken.se...pa-fran-power-plant.html

http://odlingsbutiken.se...-blom-mh-vaxt-lampa.html

LED technology is in constant development, so there might be options, but most likely the best fixtures available will be VERY expensive and the results a little impredictable.

CFLs can do the trick, but spectrum wise a metal halide lamp will work better for a plant that needs to be kept at constant vegetative growth like your cacti.

However, I just remembered this post by Snozzleberry. That might be a very good option too, you just have to purchase the right ballast.

Thanks for the help, although i will not buy any growing lights from outside the country since the police here are crazy looking for weed growers!


Even most of the growshops are under regular surveilance and people have been picked up by police after coming out from them and some have even gotten raided homes just because they had been checking out a store!

So most likely i will buy a mh lamp with ballast from some of the local shops offering shipping.

Good luck with that.

The situation you describe sounds scary. Nothing at all like here, cross my fingers. I have two grow shops in my area, with good business since long, and when approaching one of them the incense masking smell slaps you in the face