When should I start marigold seeds indoors to ensure optimal growth and flowering for my garden? Is there a particular time frame that aligns with the last frost dates in my region? What methods can I employ to accurately gauge when the conditions are just right for planting? Could it be beneficial to consider the specific variety of marigold I’m planning to cultivate, as some may require different timelines for germination and robust development? How does light exposure and ambient temperature during the starting phase influence the success of my seedlings? Furthermore, should I take into account the overall length of the growing season in my area, and how might that impact my decision to initiate the seeding process indoors versus directly in the garden? Are there specific indicators or signs that I should be vigilant for as I prepare to embark on this horticultural endeavor?