This is the famous plant for cleaning soil of harmful root knot nematodes and repelling many garden pests while attracting pollinators. Maturing at a monstrous 10 feet in optimum conditions, these will provide mid-summer shade for all those in need. Horticulturally, it has so many uses as well as providing a bounty of anti-viral and anti-bacterial medicine for flu season, making this an essential plant for the organic herb garden. These flowers are for working your soil, not for being pretty – because they’re not. Also used as an ingredient in South American cuisine.
Nematicidal marigold flowers late in the season. One trick for the insecticidal use of the plant is to have several plants in pots and move the pots around to and allow rain and irrigation to drain through the pot, thus applying the “poison” that is created in the root zone during flowering to many locations. The sap of the plant may cause skin irritation or photodermatitis.
Common name: Nematicidal marigold, huacatay, stinking roger, black mint, miniature marigold
Botanical name: Tagetes minuta
Type: Self seeding tender annual.
Scarification/Stratification: None required.
Hardiness: 33F and not frost hardy.
Sow temp/season: 65-85F in mid spring to mid summer if you have enough time before frost.
Sow depth/spacing: Surface sow and press hard at one seed per inch.
Germination time: Between 1 and 2 weeks
Final spacing: 2 feet
Final height/spread: 7-10 feet high and 18” spread
pH range: 5.8-7.4
Soil type: Any well-drained soil.
Nutrition Likes Nitrogen for growth and Phosphorous and Potassium for flowering. Not a lot of feed. Just a bit.
Drainage: Does not like wet feet.
Water requirement: A steady water supply is good. Few deep waterings to make deep roots is what it likes.
Sun: Full sun to part shade.
Time to maturity: 100-120 days.
Hilling: A couple of inches will be good.
Propagation: Sow seed in a minimum of one inch pots/plugs and transplant up to landscape or a 3-5 gallon pot.
Hybridization: Plant separate types of marigold a minimum of 50 feet apart if one intends on saving seed.
Uses: Strong insecticide or tea for colds and sickness.