Sunflower

Sunflower

Helianthus annuus

 

Originally, cultivated by North American Indians Sunflowers have a variety of uses, snacks, fodder feed, bird food and oil. The sunflower head tracks the sun. Each sunflower head has two different types of flowers, the yellow petals around the edge of the head are individual ray flowers and the face of the head is made up of hundreds of disk flowers that each form a seed.

 

pros

  • vigorous growth so competes with most weeds
  • germination at around 7 degrees celsius
  • planting depth is 3-4 cm
  • tolerates soils with pH down to 6 -5.5 prefers high pH
  • resistant to many pests 
  • water-efficient 
  • high in nutrients,
  • valuable in cover crops - used in a rotational or a break crop, sunflowers have plenty of benefits 
  • large tap-root systems which break up the soil, helping recycle nutrients and performance of future crops
  • roots increase the organic content of soil thus increases its water holding capacity of soil
  • the roots help with contaminated soil by helping detox heavy metals from the soil, like lead, arsenic, zinc, chromium, cadmium, copper and manganese
  • a fungus has root symbiotic relationship with the sunflower, it takes mineral phosphorous, which plants can’t absorb and transforms it into a phosphorous that plants can use to grow.

 

Cons

  • The larger hull of sunflowers requires ample moisture to penetrate the hull for germination. 
  • water-hungry - depletion of soil moisture in a crop