water Bottom watering

[LSUtigers]

My plants are now just getting their first set of true leaves so I want to start bottom watering. But when I bottom water for 20 minutes, the top never gets damp. In fact it seems like the top 1.5 inches never gets damp. Should I be letting them sit for longer? In the picture the dry spots never get damp. The dampness on the surface is from previous top watering.

 

[Edmick]

For 1.5 inches of soil to not get damp tells me you're not adding enough water but if the seedlings are doing well then stick with it. It encourages deep roots and discourages nasty stuff like damping off and fungus gnats.

 

[CaneDog]

If they get too dry - or depending on the nature of the soil mix you're using - it may interfere with the capillary action of the soil lifting the water through the medium. In that case spraying the soil from above may get it going again. It's also possible your soil mix isn't ideal for bottom watering, which can make it more difficult.

 

[sinensis]

moss seems particularly susceptible to this. once it gets below a certain moisture content, it becomes hydrophobic and then is a real bitch to evenly rehydrate. i hate it. commercial mixes address this by using wetting agents (surfactants).

 

[karoo]

Best for bottom watering and wicking in my experience , 50/50 Coco Coir and compost.