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Windowsill cactuses still no sign of life

Posted: Mon Apr 04, 2011 3:06 pm
by bobfnbarker
I'm doing the plastic bag mini-greenhouse windowsill try to get the cactuses to sprout and almost 2 weeks in still no sign of success

Setup:

cactus soil (no fertilizer)
keeping the soil moist by a spray bottle once every 2 or so days
60 watt flourescent on about 12 hours a day

since i haven't seen any success i just put a heating pad under them today

is the flourescent not a high enough wattage?

the plastic bags have openings for ventilation

Posted: Mon Apr 04, 2011 3:21 pm
by iann
You have it inside a plastic bag and you're spraying every day? Something very wrong there. The plastic bag is so the soil doesn't dry out and you don't have to spray or water. A regularly opened plastic bag is just a breeding ground for all sorts of nasties. Either leave it closed (bit late now!) or open it and spray regularly.

The light is almost irrelevant. Light from a window is most likely far brighter than anything you are adding. I have no idea what a "60W fluorescent" is and no way to judge how much of it your are concentrating on your plant pot. It may even be blocking more natural light than it supplies.

The light is still irrelevant. Most cactus seeds need light to germinate but not much and it is hard to imagine they are in a window and not getting enough.

Temperature is quite important. Much below 20C and most cactus seeds won't germinate. Most are good at about 25C, some need it warmer. A plastic bag sitting in a window is likely either way too hot (in the sun) or not warm enough (not in the sun). This is my first guess for the main problem. The heat pad may help if it isn't warm enough.

Seed might be bad. What is it and where from? This is my second guess for the main problem. Most cactus seed germinates fairly well and stores fairly well, but some is difficult even when the seed is viable and some doesn't store at all well. It isn't at all simple to test seed for viability and even good sellers often supply seed that is simply dead.