How long to leave seedlings in humidity dome?

[Jamz108]

Humidity domes simply keep the medium from drying too quickly when you are using heat mats to aid germination. Heat mats are designed to raise the temperature 10-15 degrees F. above room temperature (to around 80 degrees) and this aids in germination and root developement. Humidity is not so much a factor in germination as root zone temperature is.

Be cautious when using a humidity dome because the medium can also become too wet which will actually slow root growth from lack of oxygen or create fungal problems. In my opinion, humidity domes and heat mats are really only useful for cuttings because they have no intention of forming roots and you must make every effort to force them to create them via rooting hormones, heat mats, humidity domes, etc. The tap root of a seed on the other hand intends to form roots and will even without the aid of a humidity dome.

Once the seedlings have there true leaves (first set of 1 finger leaves above the cotyledons) then remove the humidity dome.

Thank you so much for intelligent insight

 

[budnoob3]

To add, if you haven’t heard the term dome of death yet you will and many of points noted are why the best of seeds you can just start in soil on a window sill and have a successful start or the worst can be soaked with hormone solution added and go nowhere. This is why it’s so difficult to have predictable results and for new growers it comes down to luck at times. My personal favorite scenario is to germinate outside without having to resort to soaking, domes, etc. In winter indoor starts where I do use heating pad and moist paper towel method I still avoid dome when possible. When I do resort to a dome it’s because I’m going to be busy with other obligations and unable to monitor and maintain appropriate moisture levels. The key then becomes not being away too long because they’ll most likely wilt and die off from too much moisture or getting too dried out in absence. Or they’ll take off and stretch into top of dome and fall over etc. once they sprout you need to gradually reduce moisture and acclimate them with vents initially then periodic dome removal with gentle fan activity to help build strength in my experience. If stretching approaching top of dome it’s time to add some medium to help stay standing and increase size of dome. Changes can happen very suddenly and quickly in early stages hence the need to be vigilant. Honestly avoid domes as much as possible in favor of simpler methods but sometimes a necessary evil