Greenhouse Tomatoes
Some of the leaves on my plants are turning yellow. What is causing this?
Yellowing leaves can be caused by several situations. The following are the most common:
1) Early Blight (fungus) - If this is the cause, you should see small circular brown lesions on the leaves as well. The spots become larger. Eventually, bottom leaves fall off.
2) Shading - As the plants mature, the bottom leaves get heavily shaded and naturally turn yellow as they senesce (age). This is not a problem. Any yellowing leaves are no longer productive and should be removed to improve air circulation.
3) Low nitrogen or potassium - If the nitrogen or potassium level is too low, yellowing will occur. Nitrogen deficiency shows up as a general yellowing of the entire plant. Potassium deficiency will appear as bright yellow leaf margins (edges) on otherwise green leaves.
4) Low Magnesium - Interveinal yellowing on older leaves is from low magnesium. If this is suspected, spray 2 TBL per gallon of magnesium sulfate (epsom salt) on the plants and see if they "green up" in a few days. For all suspected nutrient problems, a tissue analysis is recommended.
Greenhouse Tomatoes
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- At what color should greenhouse tomatoes be harvested?
- Can I grow multiple crops with my greenhouse tomatoes?
- Can I use a vibrating toothbrush rather than the expensive electric pollinators?
- Diseases and Abiotic Problems of Greenhouse Tomatoes
- How can I get answers to other questions which I don't find on this Web site?
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- How many greenhouses do I need in order to get rich?
- How many plants can I grow?
- How much yield can I expect per plant?
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- Should I test my well water before irrigating my greenhouse tomatoes?
- Should I use supplemental lighting to increase my yield?
- Some of the leaves on my plants are turning yellow. What is causing this?
- The fruit are setting and have good size, but they have strange shapes. Why?
- There are cracks in the fruit. Now what?
- What are those funny little white flies on my plants?
- What is the fuzzy looking gray colored mold growing on my plants?
- What kind of fertilizer can I use for greenhouse tomatoes?
- What pH should I use?
- What variety of tomato should I use in the greenhouse?
- Where can I get help in learning more about greenhouse tomatoes?
- Why are my plants so tall, like they are stretched?
- Why are my plants wilting?
- Why do many fruit have a blackish area on the bottom?
- Why do the plants get flowers, but don't get fruit?
- Why do the plants produce fruit that are too small?