I have trouble with starting seeds indoor this year. I have a low germination rate and my tiny seedlings have flopped to the ground when I come back home from work.

One perks up after watering but the others are dead.

I have installed a thermometer/hygrometer and the temperature is at 22 C and the humidity is at 31%.

My house is very dry in winter.

Do I need to increase the air humidity to prevent the things drying out too fast?


The best way to provide plenty of humidity is to cover your seedlings with Saranwrap type plastic or a dome made for your starting flats. I always do this even for rooting vegetative starts. Don't need light to germinate seeds, do that in paper towels in ziplocs then transplant into potting soil or potting soil for starts. I use a sprayer to moisten the top of the soil cover with a plastic for humidity. Make sure you don't put the seedlings in direct sunlight but an artificial light can be controlled so you don't cook your babies. This also prevents mice/rats from dining on sprouts. Later, after at least 2 sets of leaves you can allow them to deal with whatever humidity you have. High humidity ain't so great as the plants get older as it promotes fungus. When my starts get going they get a fan 24/7 to push the air around as well as blowing off the O2 produced by the plant during photosynthesis to allow CO2 availability.

  • What is the advantage of using ziplocs with paper towels over planting directly in a seed tray? – Gilles Mar 26 '17 at 1:38
  • What you are talking about is germination of some types of seed to observe the viability of your seed as well as giving them a head start. As soon as the seed coat breaks via life pushing it outwards and a tiny tail of root shows, that plant gets planted in potting soil in a tiny pot. Only the surface around the seed is kept moist by spraying water until the plant gets its second set of leaves or thereabouts. If indoors there should be a grow light. Covering with plastic keeps the moisture in and lasts longer. Larger seeds are soaked overnight to get them started and then they are planted. – stormy Mar 26 '17 at 16:22
  • If you've got new seed such as lettuces, broccoli, squash, peppers, tomatoes...planting directly into potting soil in seed starter trays is perfect. Some types of plants hate being transplanted and is usually printed on the directions of the seed packet...such as corn. These plants should be directly sowed in the larger body of the garden, not in pots. When you have limited space and only a few seeds it is a good idea to germinate in paper towels/ziploc bags (moist but not dripping wet). There will be seeds that just do not germinate and you don't have to waste your time or resources. – stormy Mar 26 '17 at 16:29

It's fine. That's almost exactly what my indoor gardens are at all winter.

Heating pads are a good idea if the soil will drop too low in temp.

It's more important to use a germ/clone potting mix that will promote a healthy long-term root ball, to eliminate cold drafts on young plants, and to know when to mist them.

What stormy said about mice is correct - and the only reason I'd go back to covering seedlings if I move to an area where mice are an issue. They will gobble up sprouts with no remorse.

  • I always cover seedlings with plastic or a dome. Mainly because I don't want to constantly be watching the moisture level. This makes watering far easier with more constant conditions. Not too much, not too little. Otherwise one has to factor in heat, light, evaporation/humidity until those babies are more able to adapt and wait for water. Heating pads are super! But the soil being warmed will cause the moisture to evaporate into the dry air much more quickly. Can be done but I don't like being chained to my baby plants as I can easily be distracted. Too dry, too wet...too bad. Grins! – stormy Mar 26 '17 at 16:35
  • Oh, misting has been shown to be completely ineffective. Doesn't do a thing for humidity. Great to wash off dust...but babies haven't been around long enough to gather dust. Easy peasy just to cover with plastic, popsicle sticks or a dome and you've got more elbow room for mistakes...and keeping mice out. Man, that was a hard lesson to learn! Once plants are larger no problem but those tender babies are loved by rodents. And the plastic also prevents drafts as well. I am the LAZIEST gardener in the world but I want to be successful as well!! – stormy Mar 26 '17 at 16:40
  • If you've got rodents, you need the barrier. I grew up in the country - I know the reality. Every country house has mice, and the ones that say they don't are either fibbing or don't know what a mouse dropping looks like. I'm in the city now, and nearly all of my sales are grown or began indoors. No mice, but fungus is among us - to the Nth degree. Germinating/cloning with a cover, at least here, is considerably more work and cost than a misting regimen (which is just for gentle moistening - the humidity increase only lasts 30-45 minutes). I haven't noticed any significant disparities in – Paul Nardini Mar 27 '17 at 1:52
  • 2) success rates among the few (non-succulent) species I propagate over winter, but then I keep a constant temp and give my trays and tables a once-over daily inspection (and a lesser inspection in the afternoon if I made a mental note that someone needed attention for something.) If you want to cheat humidity in the winter, you can use the time to propagate succulents. I've got a few trays of Jade and various others that were more than happy to root in dry air. -- idk, I'm bouncing between clones and seedlings in what I'm talking about. I don't find covering to be necessary for either, but – Paul Nardini Mar 27 '17 at 2:03
  • I also don't have mice. idk, i started falling asleep at the wheel halfway through this, Stormy. Spent the last several hours prepping a cache heavy duty F.G. 5-gals I got from a friend, for a host of junipers I need to transplant. (why spend $20 on an air pot when you can make one in 15 minutes with a drill?) -- but spending hours cleaning and drilling plastic buckets leads to derpy comment chains like this one. I'm outta here. – Paul Nardini Mar 27 '17 at 2:13

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