Basil and marigolds can grow together in a sunny, well-drained bed or a large enough container. Keep the basil accessible for frequent harvest and choose a marigold that will not shade or crowd it. Their main benefit is a useful combination of herbs and flowers, not guaranteed pest protection or improved basil flavor.
Choose the marigold around the basil
A compact marigold is usually easier to place beside basil in a small pot than a tall, broad variety. Read the mature height and width on both labels. Leave enough space for the basil to branch without growing through the marigold’s foliage.
In a bed, put the basil near an accessible edge and arrange marigolds so that harvesting does not require stepping on the soil. In a container, use a pot with drainage holes and enough root volume for both mature plants. Two crowded plants in a small decorative pot will need more attention, not less.
Plant when the weather is warm enough
Basil is sensitive to cold. Wait until local conditions are suitable rather than assuming that a warm afternoon means the soil and overnight temperatures are ready. Acclimate indoor-grown plants gradually before moving them outside permanently.
Follow the seed packet for sowing depth and germination instructions if starting either plant from seed. Their seeds are not interchangeable, and one universal sowing depth can give poor results. Set transplants at an appropriate depth for the plant and water them in.
Water and feed according to the growing medium
Check moisture near the roots. Water thoroughly when needed and let excess water drain from pots. Avoid leaving a container standing in water. Plants in a small pot may need checking much more often than established plants in garden soil.
Living marigolds do not feed basil essential nutrients simply by growing beside it. Use suitable soil or container mix, and add fertilizer only as needed for that medium and the plants. Too much feeding can encourage leafy marigold growth with fewer flowers; routine weekly fertilizing is not necessary in every bed.
Harvest basil and maintain the flowers
Harvest basil by cutting a shoot just above a pair of leaves, leaving healthy foliage to support regrowth. Pinch out developing flower spikes when your priority is leaf production. The University of Minnesota’s basil guide covers its growing and harvesting needs.
On the marigold, remove faded or spent flowers for a tidy display. A fully opened, healthy flower is not the same as a spent flower. Check the marigold growing guide for differences among common types.
Respond to actual problems
Inspect leaves for insects, disease and moisture stress. Do not rely on the scent of either plant to prevent infestation. Any pesticide used around the basil must be permitted for its edible use, with all label directions followed.
If you prefer trailing flowers around the pot edge, the marigold and nasturtium combination needs a different layout. If you are planting beside a permanent crop, see the separate basil and asparagus guide.
