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Hardening off cacti seedlings

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I've read on the wiki, and Erowid, and searched on these forums, but can't find any *specific* info on hardening-off cactus seedlings. There's plenty of details on the germination itself, and the following months of after-care, with mistings, low light levels, etc.

But nowhere can I read anything that tells me HOW to harden-off.

I germinated some Loph and Trich seedlings around February this year, and kept them in a covered, sealed box, with a few millimetres of water at the bottom for about 2 months. (The box has been outdoor the whole time, so it's not a huge shock when I finally do get them hardened-off and out in the cool mountains air)

Just as the frosts in my area started to end (about 1-2 months ago) I removed the cling-wrap from the box, and attached muslin over the top. I now let the cacti dry out for about 1 day between mistings (which means I spray them twice a week or so). But they've started to go a bit red/purple since it's been getting sunnier, so I've moved the boxes to a much shadier spot.

They've all got little hairs/spines all over them, and are getting to a decent size (2-3cm) so I want to start to harden them off for summer. How do I do this? I wouldn't want to lose them after all this time and care! Especially considering I managed to nurture them through winter, which was obviously the worst time to be growing baby cactus.

How do you guys harden off your seedlings?

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just look at the conditions your mature plants are in and then the conditions of your seedlings and gradually work them up. imo you should stop looking for such specific advice and just use your intuition and find methods to work with your own environment and materials available. there is no 'how its done' technique.

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quote:


After four to five months (when spines have formed on seedlings) remove the muslin shading for one or two hours a day to give the seedlings more light. Stop bottom watering and use a watering can twice a week. Water around the seedlings, not on top of them. The seedlings should be misted occasionally (not a lot) in hot weather. Seedlings should be brought inside for their first winter, and kept moist (they cant handle very cold weather). They should be placed in a sunny window away from cold drafts.

http://www.erowid.org/plants/cacti/cacti_g...ti_guide4.shtml

Wasn't too hard was it? :)

EDIT:

Also this one

http://www.ethnobotanica.org/wiki/index.ph...w_1000_cacti.21

 

quote:


Leave the glass on untill the seedlings start to grow and develop small spines, The longer you can leave the glass on and keep the humidity up without rot the better. When removing the glass slowly increase the amount of air they get and when the glass is only covering about halfway then take the rest off. At the first sign of rot take the glass off. Bottom water the boxes when the top few cm are dry. I like to put a small amount of uniform size sand particles about 2mm over the surface as soon as good percentage have germinated, then as they grow I sprinkle more over them untill they have nice support, this also helps to knock off those stubborn seed shells. Make sure they get enough water and dont shrivel up. Keep them in the shade untill they start to grow then slowly expose them to more light.

 


[ 28. September 2005, 03:26: Message edited by: apothecary ]

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No, it wasn't, but I said I'd already been through erowid.

How about you answer my question, Mr. Smarty Pantaloons:

quote:

How do you guys harden off your seedlings?

YOUR seedlings.

:D

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Right after my germination period I take the lids off of the containers and start using dilute fertz. I let the majority of the germinated seedlings root into the medium before removing lids. Once they have germinated though I open the lids on one side, just crack them a bit, to get a bit more air circulation while still keeping humidity in. When I have removed all the lids, it is after they have formed some small areoles and spines.

I let the mix start to get dry but keep a close eye on it so it doesn't damage the tiny seedlings. This seems to help them root and establish well and gets them use to the arid conditions in my house. When I do water seedlings that small I mist them with a pump sprayer. A spray bottle will work well too.

After they grow 5cm+ tall (about six months for many Trichocereus) I then put them under a HPS light with a fan that exposes them to bright conditions. Once they have grown a bit under this I take them outside and can put them right into partial sun and they adjust quickly. If I am taking them from the fluorecents to sun I put them in a shady spot that gets an hour of sun or so but not much more. The idea is that it gets daylight or filtered light but not full sun. After a couple of weeks there I take them to part sun, and after part sun they may go into a more full sun position with as much sun as I can give them.

Much of it is based on feel and observation. It is also step by step with a rotation type scheme for me. They get used to dry conditions very early.

I get red tones all the time, but pay no attention to them if the plants are growing. Sometimes a plant will turn a bit reddish when put in the part sun condition and then turn green again over a week or two and keep growing.

I watch out for a bleached pale look that shows sunburn and overly bright conditions, I never get it under lights but I have seen it under sunlight.

[ 28. September 2005, 03:52: Message edited by: Archaea ]

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Just the kind of real-world info I'm after, thanks for helping Archaea.

Apo: thanks for nothing! :P :D

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Sure thing.

Also if the whole plant goes reddish and stops growing, then I try to move it to a less brioght condition, but seem to put it back into the bright conditions after it has become more established.

I have had this with sun, but not with lights so far.

In spring when my collection comes out into sun from inside after being dormant, I introduce to sun much the same as with seedlings coming from under fluorecents, even with meter tall plants.

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after being under HID lights all winter, and after all danger of frost is gone, i put in indirect sunlight and give ferts

they respiond very quickly and the skin hardens and they look better in sunlights

after this i repot into individual pots and keep in indircet light until they are powering with a good roots ystem

then it sok to go in full sun but small cacti are always more sensitive till they are maybe 15cm tall

just do it SLOW

and dont be tempted to put out early

i killed some of my best buy going too soon an dthe frost F**kd them

4 weeks later and the ones that were snmaller and now bigger than the stundted and morbidly wounded stocks

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Cool, so it sounds like introducing fertilisers is a good way to harden them aswell?

Well, mine have always been outside, even during the frosts (but under cover of course), so hopefully the cold won't be a big issue for them.

I don't really have room inside for plants, stupid small house. :)

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I live in a trailer.

White trash all the way.

I wish I lived in a small house.

[ 29. September 2005, 01:48: Message edited by: Archaea ]

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On 28/09/2005 at 6:27 PM, apothecary said:

That's a lorax technique ^^ :)

Lol

 

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Jeez.  That comment is obviously still funny after 15 years... :lol:

  • Like 1

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On 03/01/2021 at 6:48 PM, mr b.caapi said:

Jeez.  That comment is obviously still funny after 15 years... :lol:

 

Man, you've been a member for 18 years!!! How long was the forum running for before you joined? 

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