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djkswiss

Purple leaves tomato plants

djkswiss
15 years ago

Hello folks, hopefully I can provide enough information for you to help me. This is my first hydroponic setup, I purchased a kit from Stealth Hydroponics. This kit consists of a reservoir, six net pots that have drip irrigation coming into them and 2 air stones. They give you packets of nutrients that they call "fire and forget". I am growing 6 plants, 2 cucumbers, 2 peppers, and 2 tomatoes. Now the cucumbers are doing awesome, they have about 3 sets of full leaves with more to come, they might have a little leaf burn on the outer edges. The pepper plants look very healthy, no problems there. However the tomato plants older leaves are drooping and have purple undersides of the leaves. The PH of the solution is at 6.5 which should be ideal for all the plants I am growing. I do not have an EC meter but I don't think it is lack of nutrients seeing as the other plants are thriving. I am growing these under a 400w CMH bulb. The drip irrigation is on 24/7, could this be the problem? Your help will be greatly appreciated.

Comments (7)

  • freemangreens
    15 years ago

    Tip burn and purple-colored leaf veins are two important clues. Your problem is nutrient level -- as in not enough!

    Running the system 24/7 may also be a contributing factor in that your nutrient solution may be evaporating. Check it daily.

    I've had both problems and as soon as I up my feeding, both problems go away.

    God bless.

    :O)

  • djkswiss
    Original Author
    15 years ago

    Thanks for your reply freemangreens!

    I just wanted to clarify a couple of things / ask some addition questions.

    I thought tip burn was caused by too much nutrients(I may be wrong I am new to hydroponics)

    Also the veins themselves don't actually appear to be purple it is the entire underside of the older leaves(the older the leave the more purple it is). Also the lower part of the stem appears to be purple as well.

    Thanks for your help!

  • greystoke
    15 years ago

    That MAY indicated a phophate shortage.

  • freemangreens
    15 years ago

    Yup. It was one of those times when you hit the "Submit" button and at the same time know you should edit your message, but hit the silly thing anyway.

    At that moment, I realized I should have put in a little "disclaimer" as it were, that DEPENDING ON CULTIVAR, tip burn and purple coloring are usually too little nutrient, but as is in the case of strawberries; the opposite is true.

    I know for a fact that purplish TOMATO leaves signify a need for more nutrient (nitrogen mostly). Every time it has happened to me and I upped the EC, the plants flourished.

    :O)

  • djkswiss
    Original Author
    15 years ago

    Okay, now I am going to hijack my own thread.

    It seems like I need an EC meter, can anybody recommend a good quality affordable unit?

    Thanks again for your help everybody, its much appreciated!

  • willardb3
    15 years ago

    Get both an EC and a Ph meter. Water/nutrient control is critical to success with hydro.

    EC and Ph meters can be found at worms way

    http://www.wormsway.com/

  • joe.jr317
    15 years ago

    Nutrient levels can be tricky at times. One reason is that not all plants need the same levels of nutrients overall or even individually. "Tip burn" can be too much nitrogen. In fact, it's common when people use too much in the soil garden. The underside of the leaf turning purple is usually a sign of phosphorous deficiency. That doesn't mean too little nutrient. It means too little of THAT nutrient. Some varieties are a little more prone than others and I've seen some plants that tend to have a purple tinge all season long in soil.

    Purple is not a symptom of lack of nitrogen, freemangreens. Yellow is. Did you mean phosphorous?

    The purpling of leaves means the plant needs more phosphorous. It doesn't, however, mean for a fact that your solution is lacking it. Cold water temperatures can inhibit phosphorous uptake. pH swings can, too.

    djkswiss didn't state how old the plants are. Often, young tomato plants get a little purple in hydro because they need more phosphorous for the root production at that stage.

    What is leaf burn? It's the name of a symptom that is caused by many things. In ground gardens it's usually caused by over fertilizing. It's often called nitrogen burn. In hydro, it's more likely from (as freemangreens pointed out) too little nutrient uptake. This might be from too little nutrient. It might be from too cold of solution. It might be from poor pH. You seem to have ruled out the pH, so you need to check the other two. Personally, given the plants you're growing, I would switch to a bloom solution or multipurpose blend as opposed to a grow/vegetative solution. The fact that your "burn" is on your cucumber leaf tips indicates that might be suffering a slight potassium deficiency. If it is a nitrogen deficiency, more than the tips would be "burnt" and the effects are apparent a lot faster. It would affect the inner portions of the leaf area, as well. Again, switch to a bloom solution. For peppers, I stopped using grow solutions entirely. I wouldn't do that with cucumbers, though. Optimum for peppers is not the same as optimum for cucumbers. I'd not grow them together (in the same solution, that is).

    Nobody should be telling you what you should do or what will work since we don't have enough info. We are just telling you what we would do based on the image in our heads, which could easily be different for all of us due to interpretation. The best info is a good picture coupled with EC, age, lighting, temperatures (air and water), any recent changes, most of which you did a great job of providing.


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