What's wrong with my plants (how to find out?)

I've got at least a dozen books on homesteading, hobby farming, etc in my home library, and numerous websites and blogs that I read frequently, and I seem to get by when it comes to general information about how to start gardening. But it seems like whenever I run into problems in the garden -- pests, mildew, or funny looking yellow leaves -- I have no idea what to do. I need some kind of in-depth trouble shooting guide for when things go wrong in the garden. What kinds of resources are out there, and where do you turn?

(I apologize if this has been asked before. I'm pretty new to this website, and I didn't see anything upon first inspection.) Thanks for your help!

Howdy CR, welcome to permies!

Lots of times if you post a picture here at permies, in the correct forum, and explain what you have done so far, what you are seeing, as much info as you can think of, you will get some answers to your questions.

We have loads of people here who have been gardening for a long time and have seen a lot of different things.

So is there something in particular, that you have going on right now ,that you want to ask about?

Well, right now I've got some seedlings started in the window -- tomatoes, lettuce, calendula, and broccoli. There are little black flies that seem like they are living in the soil that I bought, and the leaves at the base of the plants are beginning to turn yellow and wilt. I tried taking pictures, not sure if they are helpful or not. I also had some kind of mold (I think) that started growing in some of the seed starter (growing medium) that I had bought, but I sprinkled the soil with baking soda and watered in, and then I transplanted into different soil about 24 hours later, and I haven't seen any more of that since then.

Fungus gnats.

They are part of the normal soil biota, but in indoor or greenhouse settings, where their predators are absent, they can build up to detrimental levels. But they do indicate that you have healthy soil with lots of fungi present (or else they would find a better place to hang out).

If the weather is good, don't keep the seedlings inside any longer than you have to. Get them out and hardened off and into the ground. The fungi and the fungus gnat larvae will be part of your garden soil biota.

There are people that attribute fungus gnats to keeping the soil too damp, and it is true that damp soil makes for more fungi, which breeds more fungus gnats. But the alternative, putting your seedlings into drought stress so the fungi and their associated gnats die off is really counterproductive.

I have a worm bin inside and I have a ton of those gnats. I was never too sure what they were doing but I just let them be.
Now I know exactly what they are.
I keep my worm outside in in the summer with ground contact and bring it inside elevated on its base for the winter.
That must be why it has so much fungus, because I never had them the year before.

As to why the leaves are yellow, not enough sunlight, soil/air temperature drop (due to watering). nutrient imbalance.

I suspect that the yellow leaves might be due to a nutrient imbalance (or PH?). I'm not exactly sure how to fix that. I've heard that compost can help with stuff like that, but I don't have any yet, and I don't know what to add or how much, or even where to buy it. I feel like the more I try to read up on soil amendments, the more confused I get!

To my experience anyway, light green to yellow leaves would mebbe indicate Nitrogen was lacking. Mebbe try some sort of fairly concentrated N on one or two, see what happens?

This gardening stuff is kinda hit n miss sometimes. Also a lot like being a Cub fan, "Wait'll next year!"

Good luck to you!

Next time starts some beans and then add the tomatoes after the beans sprout.

For even all over yellow on older leaves more than younger leaves I'd suspect nitrogen too. Plants will translocate N from old leaves to new if it is short. Blood is nice (you figure out how to get it...), I haven't used dilute urine on seedlings. A little manure tea would work. A little wind can help them stay stockier. Ditto on the fungus gnats... biodegradable soap spray on surface can do it too for most soft bodied bugs that you can't wash off, but I haven't had impacts from fungus gnats.

For the larger question, gourmet garden shops (not Lowes) often have a few experienced gardeners you can take samples too. That is where I learned. Your land grant college extension agent is another resource... there are 'Master Gardener' clinics in my state. They also have the best publications that describe the most common pests for common plants. A good IPM textbook is a good read... Integrated Pest Management... if you are serious. You have to learn your 'pests' as well as your desired species.

I’ve been meaning to buy this book.
http://www.amazon.com/dp/0881929611/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2Y9X6WN3BC8OC&coliid=ITBNAV6FZWHNS

-What's Wrong With My Plant? (And How Do I Fix It?): A Visual Guide to Easy Diagnosis and Organic Remedies”
David Deardorff

But personally I’m not the type of person that likes to get stressed over plant diseases. I prefer the mindset of “if it is sick, nature doesn’t want it in this position, at this time, and under these conditions.”

A lot of plant diseases have to do with them not being able to access nutrients. I also prefer to go to the root of the problem, which I believe is the lack of nutrients or lack of nutrient accessibility.

As for pests coming, they seem to attack weak plants (nutrients again) and leave healthy plants alone. The other aspect is the predator-prey relationship. A lot of times you just don’t have a decent predator in the vicinity, which usually points to a lack of diversity in planting or habitat, or the predators haven’t come because there isn’t a sufficient build-up of prey.

So far, I’ve been able to slough off most of the garden problems because the problems are less than 20% of the harvest, which I think is a good rule to live by. It saves you from stressing over a single plant and allows you to work at the level of the ecosystem.

But, again, I think the book such as this would be helpful and perhaps broaden anyone's perspective on this.

William

UPDATE:

Thanks for the thoughts and tips. I will be checking out that book from the library as soon as it is available.

So I started opening the window on non-rainy days to allow a little bit more airflow. I also started mixing a small amount of human urine into their water twice a week as a weak fertilizer, and this seems to have helped their coloring. I usually don't stress over every little detail with my plants, but I do want to grow as a gardener and as this is my first time trying to start plants from seeds, I'm still trying to work out the kinks and see what works best for me. PS: the fungus knats seem to have all but disappeared ... guess they don't like hanging out in urine!

Thanks so much for the help. Wishing you a bounteous harvest!