Levels of Difficulty Growing Food
Gardeners tend to treat all food plants as though
they have the same nutritional requirements, when in fact; they
fall into three broad groups with light, medium and heavy nutritional
needs. This grouping is determined by the degree of inbreeding and
refinement required to develop different varieties and by timing
and seasonality. Gardeners that can sort food plants into groups
organized by the difficulties in growing them, increase their success
at consistently putting food on the table.
The chart below ranks members of the cabbage
family according to growing difficulty and levels of soil nutrition
needed to grow them successfully. Broccoli is rated both moderate
and difficult to grow depending on seasonality. Here, the “window
of opportunity” for planting broccoli in spring is very small,
but in fall, the only caution is having adequate soil nutrients
to accommodate broccoli’s rather small root system.
Root growth studies show that food plant varieties
that are genetically closer to their wild ancestors have root systems
that are far more capable of foraging for moisture and nutrients.
As a result, they require less concentrated soil nutrition and if
given adequate root room, by not crowding them, can produce food
with less irrigation.
Root development in Kohlrabi and Kale are about the
same and demonstrate the ability of their wild ancestors to mine
the soil. In contrast, Cauliflower has a limited root system in
relationship to above ground growth and requires careful feeding
and irrigation to produce quality food. Broccoli has a root system
similar to Cauliflower, but is more tolerant of clay soils.
When growing the more refined food plants there
are reasons to select high quality hybrid seed over heirlooms and
traditional open pollinated varieties, or searching for heirlooms
that still retain their original vigor. (subject for a different
till next time,
Darrol Shillingburg – January 2008
Doña Ana Extension Master Gardener