How beneficial is a heat map when sowing seeds?

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zagoric
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How beneficial is a heat map when sowing seeds?

Post by zagoric »

If you recommend one, any favorite I should look into?

And what temp is ideal?

Thanks.
Wilk
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Re: How beneficial is a heat map when sowing seeds?

Post by Wilk »

I assume you mean MAT.

In my experience not at all. I sow at about 20c and after germination they go under lights at about 25c
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greenknight
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Location: SW Washington State zone 8b

Re: How beneficial is a heat map when sowing seeds?

Post by greenknight »

In SoCal I don't think you need a heat mat.
Spence :mrgreen:
zagoric
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Re: How beneficial is a heat map when sowing seeds?

Post by zagoric »

Thanks to both of you. And, yes, I did mean mat.
keith
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Location: S. CA USA

Re: How beneficial is a heat map when sowing seeds?

Post by keith »

very beneficial to me and I'm in S. CA . too cold at night I think for cactus seeds. turn on at night turn off during day
kuni1234567
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Re: How beneficial is a heat map when sowing seeds?

Post by kuni1234567 »

I tried to grow seeds using a heating mat with a thermostat on top of my refrigerator and had poor germination rates. I had some success growing seeds in a seed tray with a heating mat under a covered patio. I am thinking about buying an egg propagator to germinate seeds because the night temperatures tend to be much lower than the daytime temperatures. I also live in Los Angeles near the ocean and have never had much luck with growing seeds. I believe that the main problem with growing cactus in my area is the lack of summer heat and sunshine due to cloud cover.
DaveW
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Re: How beneficial is a heat map when sowing seeds?

Post by DaveW »

In most climates seed germinates when soil temperatures are right for them, usually in Spring. Cactus seed will grow quite happily without artificial heat in the growing season in most countries that are not too cold, it's only really needed if you want to grow out of season.

A lot in the UK start their seed off out of season in January in heated propagators since it gives a longer growing season and the seedlings are much larger before winter. From about April onwards though we can just start cactus seed off in the greenhouse, just as with normal bedding plants without additional heat. As with all things it is a matter of providing ideal germination and growing conditions, which if they are not present at the time needs artificial heat or sometimes light to do so. Gentle mild bottom heat, as with your heat mat or propagator, is the ideal way to start seed out of season.

I photographed this list some time ago of seed germinated on moist filter paper in a laboratory, which gives some idea of ideal temperatures. You can get soil thermometers to test soil temperature but these are not usually necessary. As you can see from the list too high or too low temperatures actually inhibit germination, maybe seed is programmed to not germinate when temperatures would be fatal to it and to wait until they are suitable?
GERMINATION.jpg
GERMINATION.jpg (125.36 KiB) Viewed 1873 times
Yes most cactus seeds need light to germinate, so whether the interior of the room near the fridge was too dark I do not know, but would not have thought so. There are many other factors with seed germination, such as some seed germinates best when fresh almost out of the fruit, whereas other seed may need to age a few years before reaching it's maximum germination potential. Other seed needs to be stratified, that is subjected to a cold winter before it germinates. In nature the seed can lie around for many years before it germinates, whereas if we don't get germination after sowing we tend to throw the contents of the seed pots away. Also there is that other variation, how long has the seed been harvested by the seeds man when you get it? OK if it is seed that needs aging, but a problem with any that needs to be set fresh. Though with most seeds men it is seed harvested from last seasons fruits. Also "Sods Law" if it is expensive seed of a new novelty you only buy about 5 seeds of you don't get much germination, sow the same seed in hundreds when it has become common though and it often comes up like weeds!

Probably grow lights as well as heat might help in your case Kuni?
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