When cared for correctly, crackerjack marigolds will be like candy for your ornamental flower garden. Give them at least six hours of daily sun and well-draining soil with average quality. If your soil is naturally heavy, add some sand, perlite or compost. Water well at the plant’s base, but let the top layer dry between waterings. You might want to add a cage, trellis or other support so the tallest flowers don’t get leggy.

Crackerjack marigolds are known for discouraging many pests with their strong scent, from aphids and nematodes to rabbits and deer. The main pests that enjoy marigolds are slugs, caterpillars and spider mites. The flowers can also be overcome by fungal diseases in warm and humid conditions, so good air circulation is important.

Depending on the region, you can start these marigolds indoors 4-8 weeks before the last expected spring frost. Fill well-draining trays or flats with seed-starting mix and plant seeds about a quarter-inch deep. Keep the soil moist and maintain temperatures of 70-75 degrees with lots of sunlight. When the seedlings are 2-3 inches tall, thin or repot them to about 12 inches apart. At 4-6 inches tall, harden the seedlings off for up to two weeks.

The best time to sow or transplant crackerjack marigolds is about two weeks after the final frost. Sow new seeds 8-15 inches apart, thinning later if necessary. Because of their pest-deterring power, consider planting crackerjack marigolds near other crops you want to protect, except for cabbage-family plants and legumes. They’re also a great border plant for gardens and walkways.

Potting these marigolds lets you place bright colors anywhere, and it’s a great way to repel mosquitoes from a patio or pergola. You can sow one marigold plant in a standard six-inch container, with more in larger pots or flower boxes.

If the soil is decent, crackerjack marigolds don’t need much fertilizer. Amend with compost or a balanced slow-release fertilizer when you plant or transplant. If soil testing determines it’s necessary, add some high-potassium, low-nitrogen fertilizer later in the season. This promotes flower growth over foliage. Container marigolds will likely require more frequent fertilization or repotting to replenish nutrients.

Crackerjack marigolds are an annual variety that will die off in late fall regardless of the climate. After the first fall frost, remove the dead plant from the ground and compost it. In warmer growing zones, the plants will survive long enough to go to seed. Let your marigolds self-seed or collect seeds by removing faded seed heads and storing the seeds in a paper bag or envelope.

Along with removing damaged flowers and leaves, two pruning techniques will help your crackerjack marigolds thrive. When the plants are still young, pinch off the top set of leaves, which encourages more flowers and a bushier plant. After blooming, deadheading spent flower heads has the same effect.

These marigolds typically flower in 60-70 days with the blooms peaking at 4-5 inches across. To harvest for flower arrangements, cut blooms in the morning with sterile scissors or shears and add them to a water vase.