Choose shape before colour
Disco Yellow is a dwarf marigold with an accessible flower centre. Tagetes erecta gives much larger double flowers needing height room. Golden Gem has finer leaves and many small yellow blooms. Do not space every type identically; use labelled mature size.
A border you can maintain
Make edges narrow enough to reach from paths. Do not place marigolds among newly sown vegetables where later weeding obscures identification. Give them a strip at the entrance, for example, making spent flowers visible daily and watering manageable.
Use repetition
Three groups of the same type create calm among vegetables. For colour, combine small-flowered yellow with one striking large orange group. Photograph at eye level and overhead. The latter shows sufficient room or unintended overhang into vegetables.
Saving seed without surprises
Save only ripe, dry seed and label the parent. Crossed or hybrid offspring may not reproduce flowers. For an identical border next year, buy the same named variety. Reserve some heads for seed and deadhead others if continued flowering is the main aim.
Scent, flavour and use
No general edibility claim is made for Tagetes. Only the petals of Tagetes tenuifolia 'Golden Gem', explicitly described as edible, are a culinary option here; do not confuse this plant with pot marigold, Calendula officinalis.
Care, cutting and harvesting
Position plants in sun in soil where rainwater drains away. Sow indoors in spring and gradually acclimatise young plants to outdoor air. Plant out after night frosts. During drought, water directly at the roots and cut off spent flower heads. Tall Tagetes erecta may need support.
No annual woody pruning. Remove faded flowers during flowering. The plants are generally grown as annuals; healthy plant remains can be cleared afterwards. Tagetes foliage can aggravate skin allergies: wear gloves if sensitive.
Cut flowers for small bouquets when freshly open. To save your own sowing seed, let a few heads dry out completely and store the dry seed from each plant with a label.
