All plants

Kale

Brassica oleracea var. sabellica

Brassicaceae · cabbage family

Matures
65–75 days
Harvest
Continuous · Annual
Sun
4–8+ hrs
Spacing
12 in
Botanical engraving of Kale

Planting window

When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.

JanFebMarAprMayJun
Foggy●●●
Sunny●●●
JulAugSepOctNovDec
Foggy●●●
Sunny●●
Well-suitedMarginalNot suited

Sunlight

How well it does at each level of direct sun per day.

<2 hrsNot suited
2–4 hrsMarginal
4–6 hrsWell-suited
6–8 hrsWell-suited
8+ hrsWell-suited
Well-suitedMarginalNot suited

Soil depth

Root room it needs — useful for sizing raised beds and containers.

6–10"Not suited
10–15"Marginal
15–18"Well-suited
18–24"Well-suited
Well-suitedMarginalNot suited

Spacing

Room each plant needs — along the row and between rows — for sizing beds.

In-row
12 in
Between rows
18–24 in

Growth habit

The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.

Habit
Upright
Mature height
12–18 in

Stands on its own; the tallest types appreciate a stake in wind.

How to start it

Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.

Usually
Transplant
Start indoors
4 weeks ahead
Direct-sowWell-suited
TransplantWell-suited

Started under cover, then set out as a seedling.

Well-suitedMarginalNot suited

Getting started

How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.

Started from
From seed
Ideal soil temp
45–85°F
Sow depth
0.25–0.5 in
Time to emerge
4–7 days

Germinates between 40–85°F; happiest around 45–85°F.

30°F110°F
IdealWorkable

Pests & diseases

What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.

Pests3

Aphids
What it is
Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface.
What you'll see
Low to moderate numbers of leaf-feeding aphids aren't usually damaging in gardens or on trees. However, large populations can turn leaves yellow and stunt shoots; aphids can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus.
What to do
Before planting vegetables, check surrounding areas for sources of aphids and remove these sources. On the other hand, these aphid-infested weeds can sometimes provide an early source of aphid natural enemies.
Source
Cabbage Worms and Loopers
What you'll see
Worms and loopers are light to dark green. Adult loopers are gray or brown moths while cabbage worms are white butterflies. Worms and loopers chew holes in leaves and hide in kale heads.
What to do
Control worms and loopers with appropriate insecticides or biological measures.
Source
Flea Beetles
What it is
Their small size, enlarged back legs, characteristic shot-hole damage, and habit of jumping when disturbed make flea beetles easy to identify. There are numerous flea beetle species.
What you'll see
Adults feed mostly on leaves, leaving tiny pits or small holes at their feeding sites. Flea beetles feeding together can cover leaves with bleached, pitted areas or ragged holes.
What to do
Remove debris in the fall to remove any overwintering beetles. Reflective mulches applied very soon after planting and before plants become infected can be helpful.
Source

Sources

Every figure above is backed by these.