Tagetes patula. Brocade Marigold seeds produce brilliant 5cm (2") wide flowers in gold to mahogany atop 30-38cm (12-15") plants. This is a medium height marigold that works well in large containers. Grow in full sun and deadhead regularly to enjoy flowers from May to heavy frost. The plants are drought resistant, so a good candidate for xeriscaping. The flower petals are edible, and can be dried and ground to use as a replacement for saffron. The essential oils of this marigold have apparent anti-fungal properties, and have been used to fight fungal infections on plants. Brocade is a cultivar of T. patula, which is native to the highlands of central Mexico. It's a very easy flower to grow from seed.
Marigolds are annual flowers that are easy to grow from seed and resilient. They can be grown in the garden, in containers, and they play a role in Companion Planting. Some even have edible flowers! Learn how to grow Marigolds from seed, and they will earn a place in your garden every year.
When I Get My Seedling Home
Keep seedlings under very bright light to prevent legginess. Artificial lights are ideal, but a bright (ideally, south-facing) room will work for the short term. You may have to pot on seedlings more than once before they go out to allow for root growth. This is done by transplanting them into a slightly larger container with enough additional soil to keep the container mostly full. Keep the soil moist by daily watering and allow for free drainage so the plants are never sitting water.
Do not transplant outside until daytime temperatures are steadily 10°C (50°F) or warmer. This may mean keeping seedlings indoors for up to a month. The plants should not require any fertilizer until transplant time. Space plants in the garden 30-45cm (12-18″) apart. Dwarf varieties can be spaced 15cm (6″) apart.
Pinch the growing tips to encourage branching. This avoids tall, spindly plants. Dead head regularly.
French Marigolds (Tagetes patula) produce chemicals that kill nematodes and repel whitefly. Avoid planting them near beans. Mexican Marigolds (T. minuta) have the same effect, and may repel rabbits.
More on Companion Planting.