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Re: A busy day

Posted: Thu Feb 22, 2018 11:17 am
by BryanW
You can get strong UV tubes Mike, they're used for desert reptiles.

Re: A busy day

Posted: Thu Feb 22, 2018 4:58 pm
by ralphrmartin
I have never bothered with lights - in my previous greenhouse, the propagator was under the bench, and the seedlings did OK there. They are now on the bench, so should get more light. If anything, I am worried I may need to shade them.

As for diurnal temperature swings - I did think of putting in timer switches too for the propagators. However, I suspect the heating cables wont necessarily keep the set 20C at night at this time of year, given the propagators are in the unheated part of the greenhouse, so there will probably be some significant temperature swings anyway. (That part of the greenhouse itself is swinging between about 2C and 19C at present, at least on sunny days with cold nights). The greenhouse is also controlled to be cooler at night then during the day in the warmer part of the year, although I hope many seeds will have germinated by then.

As for Lobivias and Rebutias needing more UV - strangely, it seems to be that Sulcorebutias are more affected by lack of UV, despite not coming from such high altitudes as some Lobivias / Mediolobivias, etc. Years ago I wrote an article for the journal about bad experiences of trying to grow Sulcorebutias in a double-glazed-with-safety-glass conservatory, and how they all etiolated.

Re: A busy day

Posted: Thu Feb 22, 2018 5:03 pm
by BryanW
When I did lux tests last year I was quite suprised how low the light meter reads through double glazing :shock:

Re: A busy day

Posted: Thu Feb 22, 2018 5:08 pm
by ralphrmartin
Yes - and why I dont put any insulation up in winter...

Re: A busy day

Posted: Thu Feb 22, 2018 5:11 pm
by Eric Williams
Thanks Ralph for very interesting and comprehensive article on seed raising, Iam sure most of our forum friends will have found something in it to enhance their seed raising techniques. Cheers Eric

Re: A busy day

Posted: Fri Jun 10, 2022 11:50 am
by habanerocat
ralphrmartin wrote: Wed Feb 21, 2018 7:48 pm Finished filling the 2nd propagator with more seeds today. Phew. I need a rest!

To reply to some of the comments:

The propagators are heated to 20C with soil warming cables / sensors buried in sand. The sand was damped down before I put the pots in, as I want to keep the humidity up.

All the labels were pre-printed using a brother label printer, and stuck on to the plastic labels (on a dreary winter day some weeks ago).
Seeds and labels were also pre-sorted into batches, of 20-30, so I didn't have to hunt too long for the label to go with each packet of seed.

I usually use a purely mineral compost:
1 part sand
1 part fine vermiculite
1 part fine grit
1 part perlag (or cat litter etc)
1 part fine perlite
This time I couldn't get suitably fine grit, so instead of grit + sand, I used 2 parts grit sand.
All were well premixed (with a bit of water to damp it down) in my concrete, er, compost mixer. :grin:

I've got down to a fine art scooping up just the right amount of compost into a pot and quickly tipping it back level.

Pots are dunked almost to their rims (until you see the colour change) in a bucket of water to which I have added 1/2 teaspoon of my usual cactus fertiliser, and 1/2 a chinosol tablet (disinfectant). I do batches of 12-15 pots at a time.

I then empty each seed packet onto a sheet of A5 paper which a light crease in across the middle, which then lets me sprinkle the seed carefully and evenly over the damped pot, then the label is added.
I dont cover the seed except for a few succulents with really big seeds.

Pots are then put into the proagator, and given a final spray with the same mix used for dunking (tip - fill up the sprayer before you start dunking, as the dunking bucket slowly gathers bits from the compost ).

The idea is then to go out each morning, and spray the plants. Most will stay in the propagator until ready to pot on, apart from some succulents (e.g. mesems, pelargoniums) which I find do better in a less humid atmosphere.

By using mineral soil AND chinosol, I hope to avoid damping off problems. It seems to work pretty well, although I still get algae.

The key to successful seed raising is to keep the plants permanently moist. Seedlings have very different requirements to adult cacti. The baggy method works well for many people, but when you have a lot, the whole propagator replaces the bag. It has the advantage too of being able to see better what is going on.

Good luck with the retirement Mike! I've been at it for just under a year, and am enjoying it!
I have so much algae and moss this year, it's like I'm trying to start up my own Irish peat production plant. So I had to take them out of the bags early.

Quick question. Why do you spray in the morning and not in the evening?

Re: A busy day

Posted: Fri Jun 10, 2022 5:31 pm
by ralphrmartin
No real reason, it's just that I am a morning person. :grin:
But if I were to try to justify it after the event, I could say it gets hotter in the day, so a little extra evaporation during the day will help to keep the temperature down.
Some days it gets done later in the day.