The #1 cause of "bugs" in indoor plants is over-watering, keeping overly moist soil. That is what attracts them and keeps them there, not the plants and not any fertilizers.

Plus seedling tomatoes and pepper plants don't need any fertilizer feeding for several weeks anyway. But, yes, if you are going to feed them then using a well-diluted mix is less stressful for them.

Dave

PS: be sure to check out all the FAQs and growing tips over on the Growing from Seed forum here.

Listen to Dave. He's one of the most knowledgeable posters on the forum. I'll just add that the sea nutrient product probably will smell bad. (Coworkers can be SO picky!) When you do start fertilizing in the office, stick with a chemical fertilizer. Miracle Gro all purpose granular 24-8-16 or liquid 12-4-8 are good choices because they include trace minerals. If you want to use organic fertilizers, wait until the plants are growing outside in the ground.

I can understand water what keeps them alive and around. Isn't bringing them in on an outdoor plant (as I did in one case), or introducing garden soil the start of the problem? I can imagine a similar outcome using compost tea for example

So you guys would not recommend organic fertilizers but I'd like to be sure exactly what that means.

I was thinking about using Tomato Maker product diluted down at least to 1/5. This product is made by Organic Laboratories but if I recall says on the bag that it is not for organic production. So go figure. One of the components is sterilized chicken manure and it really seemed to help my tomatoes last season.

http://www.amazon.com/Organic-Laboratories-420-191-Tomato-Maker/dp/B002GK648E/ref=sr_1_1?ie=UTF8&qid=1394489197&sr=8-1&keywords=tomato+maker

Isn't bringing them in on an outdoor plant (as I did in one case), or introducing garden soil the start of the problem?

Sure it can contribute to the problem but cause it? Only if you assume they aren't indoors to begin with - which they are. Especially fungus gnats that are the most common bug problem.

Keep in mind that literally hundreds of 1000's of transplants are grown indoors annually by many of us with no pest problems. Properly maintaining the soil moisture level, and eliminating any and all over-watering, is the key.

As for using organics - IF the seedlings needed feeding and IF there is ample bacteria in the soil for them to work (which soil-less potting mixes do not contain unless you add them) and IF you don't mind the odor, no problem.

Organic fertilizers require an active soil food web to convert the nutrients in them to a form useable by the plants. If you want to use organics in containers then you have to mix in one of the bacterial supplements or use one of the mixes that already have them added.

Dave

Agree totally about the organic stuff for starting seeds. Stick with a water soluble All-purpose like ohiofem mentioned.

Couple tricks to keep fungus gnats at bay. Use a hydrogen peroxide(3%) solution diluted 4:1 water to peroxide for watering every now and then(top watering). This will kill the eggs in the soil, but not harm the plants whatsoever. You can also try sprinkling a little cinnamon around the seedlings. this works better when you're bottom watering and you have a crust on the upper layer of soil.

Kevin

IMV, nitrogen is nitrogen, potassium is potassium, etc. Anyone who has had a basic chemistry course will know that chemicals are made up of protons, electrons and neutrons in a certain combination and that doesn't change no matter what your fertilizer is. So with seedlings I don't really see a point in obsessing over organic vs inorganic. Once plants are in the garden, however, that's a different matter. There you are trying to build your soil structure, keep out salts, and recycle nutrients. I use miracle gro mixed in water at 1/4 strength.

The most common seedling bug problem is: Fungus Gnat.
FG, can only live and get into the soil IFF the top of the soil gets wet and stays wet.
So the solution is simple: KEEP THE TOP OF SOIL DRY !
How can you do that ? It is simple.

1- bottom water (about once a week; 5-8 days, depending on the pot size, soil, ...)
2- Mulch the top with small pine nuggets (~ 3/8" +/- 1/8")

If you do that FG will have no chance to get in and lay eggs/ larva. It is the larva that attacks the roots. The gnat itself feeds on fungus , developed on the wet surface.

I would like to comment that seedlings need nutritional support pretty soon after germination. I would not wait for several weeks....a few days, perhaps. Those dissolved elements are required in each of those rapidly multiplying cells and your mix won't be providing much.

Keep a close eye out for fungus gnats, though. Jiffy Mix is very conducive to those darned little things. The adult gnats don't feed on fungus! Most of them don't feed at all, a few species sip flower nectar. They are born to procreate. It is only the larvae that feeds on stuff in the soil. They will love the Jiffy Mix.

Those yellow sticky whitefly strips (traps), available at garden centers, will attract and trap fungus gnats really well.

Nice to see Rhizo1 venturing into the veggy forum lately! One of my "go-to" members in the pests and diseases forum. She's a wealth of knowledge. Usually digdirt(Dave) and many other very knowledgeable posters can answer anything asked in the veggy forum But the more great minds, the better, I say!

Kevin

Those yellow sticky whitefly strips (traps), available at garden centers, will attract and trap fungus gnats really well.

susanzone: you can make your own also.

Take a yellow cardstock, place in a clear plastic bag, cover with motor oil or tanglefoot. When the plastic loses it's stickiness/adhering quality or ther'e just too many bugs/debris, just change out the bag and start again.

Kevin

Fungus gnats could have been my issue in the past with the plant I brought to the office that had been outdoors. I've not really had issues with seed starting and bugs before now but since I was starting seeds in the office I didn't want this to be the first time.

So I have a related question, when you guys start peppers or tomatoes at how many days or at what stage of their growth do you move them to pots? I think in the past I've kept them in the tray weeks too long.

I don't do my peppers/toms in trays... I use the paper towel/baggy method(peppers) or straight into containers from the get go. But, generally you would want to do it right away so you can get them under lights right away.

Kevin