如果土壤贫瘠，请给向日葵施肥。 保护向日葵免受虫害。 检查是否有黄色的叶子。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Sunflowers do not need fertilizer, and overdoing the nitrogen can create a leggy plant with delayed flowering. If your soil is poor, add compost or slow-release fertilizer to the surface of the soil.  This should help strengthen the plant without overdosing it. Protecting your plants against slugs and snails is especially important. You can surround your plants with slug repellent from a garden store, or make your own "beer traps" for slugs to fall in. Downy mildew can be a major problem in clay