1
Fill
clean seed-starting flats with moistened, sterile seed-starting mix
when evening temperatures are still around 70 degrees Fahrenheit and it
is at least 75 days before temperatures are regularly below 50 F. This
will generally be around mid-August, but gauge by your specific climate
or microclimate.
2
Sow
seeds 1/4 inch deep and lightly cover with the seed-starting mix. They
can be kept outdoors as long as the temperatures are warm and you keep
them moist. Ornamental kale/cabbage seeds should germinate within 15
days at a temperature of 65-70 F.
3
Transplant
the strongest, most attractive seedlings to 4-inch pots filled with
potting soil about a month after they germinate. Water well. Use a
potting soil with plant food already added to the mix, or fertilize with
a balanced, water-soluble fertilizer.
4
Clear
weeds and summer annuals from an area of well-drained soil in full sun
as evening temperatures begin to regularly dip near 60 F. According to
University of California Extension, this can be from early October
through November depending on your location. The plants don't begin to
show their true colors until temperatures cool and full color can take
up to a month to develop.
5
Dig
holes equal to the root ball of each plant in full sun in their final
location as evening temperatures drop toward 60 F. Space the holes six
inches apart. While standard ornamental kale/cabbage needs 10 to 12
inches between plants to reach it peak, tight spacing encourages the
stems of varieties like Sunset to elongate.
6
Add
a scant handful of slow-release fertilizer to the bottom of each hole
and pop a small plant in each hole. Firm up the soil and water well.
Keep the plants moist as they establish in their new location.
7
Remove
lower leaves of Sunset ornamental kale/cabbage with your fingers,
beginning when the plants are 6 inches tall, continuing as they grow
until they have a red to deep pink center with one outer layer of green
to pink-streaked green leaves and a 10-inch stem. It may take up to four
weeks for color to fully develop.
8
Insert
stakes and loosely tie stems to supports once they reach 10 to 12
inches. Sunset has rosettes from 3 to 7 inches across and may grow to 24
inches tall, so though stems are fairly sturdy, supports keep the
top-heavy plant from flopping over.
9
Fertilize
once a month with a balanced, water-soluble fertilizer. While
established practice is to cease fertilizing once the plant begins to
color, as it may keep color from developing correctly, this may not be
the case. Research conducted for growers by North Carolina State
University showed that the plants can suffer from nutrient deficiencies
when fertilizer is discontinued and show no difference in color
development when the plant has regular feedings.