Forgive me if this has been asked before. I am new to bonsai, I have a 2-3 yr old Juniper that I water based off of the soil dampness.

But I am also sowing seeds to grow and keep as bonsai. I bought one of those online kits in the past, and it indicated to avoid overwatering and to only water when the soil was no longer moist. Said to keep the soil moist but not saturated. So I wanted to get some feedback on that since it was from an online kit, and not from anything I have read online.

I recently had some seeds that didn't germinate, and dug down to check the seeds out of curiosity. I noticed that in a 3 inch tall pot, only the top half inch or so was moist, the bottom 2 inches were dry. I also have them on a heat pad.

So my question is, should I be watering to essentially get all of the soil moist? And if so, maybe the heating pad is detrimental in that and drying out the soil at the bottom, so maybe I should ditch the heating pad. Or, is there no general answer to this question, it varies by species? (My next batch of seeds I plan to sow half inside, half outside, to see what I can learn)

I like to sow stuff on our windowsill, which are over the heaters. (Normally things like tomatoes and peppers); Bottom heat is great. I however use a mini-greenhouse to keep humidity up, exactly for the reasons you mention. I guess you use organic pots, pressed coco fibre or something? I hate these as they dry our VERY fast, substrate detaches and you are left with a rock of dried out substrate in a rotting pot.

I use normal plastic pots and/or pellets.
I try to keep the pot very moist. My mini greenhous has rills in the bottom, I ensure none of the pots stand over one of those, and keep the rills filled with water as to create a 100% humidity atmosphere, keeping the pots humid.

Note: If you are sowing tropical seeds, in some cases you nee to nick the seeds so they can absorb water. Even then, it can take a LONG time to germinate. My peppers regularly take 2-4 weeks to germinate. Some tropical seeds I got from a friend in Brazil took more like 1-2 months to show their face.

leatherback wrote:

My mini greenhouse has rills in the bottom, I ensure none of the pots stand over one of those, and keep the rills filled with water...

Interesting, could you take a close up picture of the rills? How do you keep the water running underneath it?

leatherback wrote:

Some tropical seeds I got from a friend in Brazil took more like 1-2 months to show their face.

Yeah, but some Maple seeds took 4 months to sprout around here. Acclimation, I guess?