Choose Dinosaur Kale for Milder Flavor, Curly Kale for Harder Winters: A Grower’s Comparison
Dinosaur kale is milder and sweeter after frost than curly kale. Here’s how to grow both types, which cultivars to pick, and when Winterbor wins.
Two Types, One Genus: What You’re Actually Choosing Between
Dinosaur kale and curly kale are both Brassica oleracea, but they belong to different cultivar groups with genuinely different growth habits, flavor profiles, and cold limits.
Dinosaur kale — also called lacinato, Tuscan, or black kale — has long, narrow leaves with a heavily embossed, bumpy texture that gives it the name. It grows as an upright rosette, 2–3 feet tall and 1–2 feet wide. Gardeners in Tuscany were cultivating it by the 18th century, and it’s been a staple of Italian cooking ever since.
Curly kale is the type most people picture first: ruffled, tightly curled leaves on stems that reach 2–4 feet tall and nearly as wide. It encompasses a wide cultivar range — green types like Winterbor, red and purple types like Redbor, and broadly cold-tolerant types like Siberian.
| Trait | Dinosaur Kale (Lacinato) | Curly Kale |
|---|---|---|
| Leaf shape | Long, flat, bumpy strap | Ruffled, tightly curled |
| Height | 2–3 ft | 2–4 ft |
| Cold limit | ~10°F (−12°C) | To −15°F (−26°C, Winterbor) |
| Days to maturity | 60–80 days (full); 25–30 (baby) | 50–70 days |
| Flavor baseline | Mild, earthy, slightly sweet | Peppery, more pronounced bitterness |
| Best kitchen use | Raw salads, quick sauté, soups | Roasting, kale chips, long braises |
The Flavor Difference — and Why Frost Makes It More Noticeable
Dinosaur kale tastes milder and sweeter than curly kale even before a single frost, and the reason is structural. Lacinato’s flat, embossed leaves have a lower surface-area-to-volume ratio compared to curly kale’s tightly ruffled foliage. Ruffling concentrates leaf cells and bitter glucosinolate compounds per bite. Lacinato’s smoother leaves deliver those same compounds more gently, which is why NC State Extension describes them as “more tender and sweeter than curly kale.”
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Frost changes the picture for both types — but the mechanism isn’t quite what most gardening articles suggest.
When temperatures drop into the above-zero single digits (roughly 2–5°C / 35–41°F), kale plants convert stored starches into soluble sugars. These sugars lower the freezing point of cell fluid, functioning as natural antifreeze. Research from the University of Oldenburg confirmed that sugar compounds in kale increase at these cool-but-not-freezing temperatures — you don’t need a hard frost to trigger sweetening, just sustained cool nights. A separate peer-reviewed study found that cold acclimatization measurably increases soluble sugar content and improves taste.
The glucosinolate picture is more nuanced. The same University of Oldenburg study found that both curly kale and lacinato kale increased glucosinolate levels at 2°C — the bitter compounds actually rise in cultivated types at low temperatures. A controlled study published in Food Chemistry added an important caveat: short-term frost exposure mainly affects aroma and texture rather than taste compounds, and concluded that “producers should not rely on frost only to obtain altered sensory properties.” Slow cold acclimatization over weeks produces more reliable sweetening than a single frost event.
What this means for harvest: kale picked in mid-October after several weeks of cool nights will taste meaningfully sweeter than kale harvested in September. Because lacinato already starts milder, the post-frost result is noticeably sweet and almost nutty. Curly kale sweetens too, but from a stronger flavor baseline, the shift is less dramatic unless you’re harvesting well into cold weather.
Cold Hardiness — Where Curly Kale Wins Clearly
If your winters regularly drop below 10°F, curly kale is the practical choice. No amount of row cover saves lacinato from sustained arctic cold.
Lacinato kale tolerates light frosts and can overwinter in the South and mild-winter climates, but it hits its limit around 10°F. In zones 5 and colder, a hard freeze that drops into the single digits will kill it. Curly kale varieties like Winterbor are rated to around −15°F in cold-hardiness trials — roughly five to six USDA hardiness zones colder than where most lacinato fails. Meadowlark (a German heritage curly variety) and Siberian kale are similarly cold-tolerant. Young plants of both types — under four to six true leaves — are more vulnerable and may sustain damage below 25°F regardless of type.
| Zone | Dinosaur Kale (Lacinato) | Curly Kale |
|---|---|---|
| 8–10 | Overwinters easily | Grows well; may bolt in warm spells |
| 7 | Overwinters with light mulch | Overwinters easily |
| 6 | Survives into December; needs row cover for winter | Survives through January without protection |
| 5 | Survives fall frosts; killed in hard winters | Survives with mulch and occasional row cover |
| 3–4 | Not suitable for overwintering | Winterbor survives; harvest late fall through light snow |
How to Grow Both Types
Both kales share the same fundamental requirements. The differences are in cultivar selection, harvest timing, and how long you can push the season.
Soil: Work the bed to 8–10 inches and incorporate up to 1 inch of compost per 100 square feet. Target pH 6.0–7.0. Below pH 6.0, clubroot becomes a risk — add garden lime if needed. Both types grow in clay, loam, or sandy soils as long as drainage is adequate.
Sun: Full sun, at least 6 hours of direct sunlight daily. Both tolerate partial shade but produce smaller leaves and slower growth.
Planting timing: For spring crops, transplant 4–5 weeks before the last frost-free date. For fall — the better growing window — count back 60–80 days from your first expected frost and transplant then. Fall kale benefits from naturally cooling temperatures through harvest.
Spacing: 12–18 inches between plants in rows 2 feet apart. Lacinato’s upright habit fits comfortably at the closer end of that range; curly kale’s spreading rosette needs the full 18 inches.
Water and fertilizer: Apply 1–2 inches per week, preferably through drip irrigation. Kale that dries out between waterings turns tough and bitter. Four weeks after transplanting, side-dress with ½ cup of a nitrogen fertilizer (21-0-0) per 10-foot row, placed 6 inches from the stem base. Avoid heavy nitrogen applications mid-season — excess nitrogen drives lush, bitter leaves and reduces cold hardiness going into fall.
Dinosaur kale specifics: Full-sized leaves are ready in 60–80 days from seed; baby greens in 25–30 days. Harvest from the bottom of the plant upward, removing the oldest outer leaves first. This creates the distinctive palm-tree silhouette — a taller, more sculptural plant than curly kale. The flat leaves wash and chop in roughly half the time of ruffled curly leaves, which matters when you’re processing large bunches. Recommended cultivars:
- Lacinato — the original Italian heirloom; reliable deep blue-green; grown at Monticello
- Black Magic — improved type with slightly milder flavor and consistent uniformity
- Dazzling Blue — blue-green leaves with purple midribs; enhanced cold-hardiness for zones 5–6
Curly kale specifics: Most varieties mature in 50–70 days. Harvest outer leaves as needed; the plant produces from the center outward and yields for weeks from a single planting. Because the leaves hold their structure under heat and in long-cooked dishes, curly kale is the better choice for soups, stews, and anything simmered for more than 20 minutes. Recommended cultivars:
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→ Find My Frost Dates- Winterbor — the gold standard for cold hardiness; 60 days; remains productive through heavy frosts and light snow
- Redbor — dark red-purple; 40–60 days; sweetens noticeably after a hard freeze; ornamentally striking
- Starbor — compact, 55 days; good for tighter beds and containers
Pests and Common Problems
Both types share the same pest pressures. The approach is identical regardless of which you’re growing.
Flea beetles are the primary early-season threat, especially on young transplants. They create small, round shot-holes in leaves. Floating row covers over transplants for the first 3–4 weeks prevent damage; remove old plant debris from the bed each fall so overwintering adults have fewer refuges.
Caterpillars (imported cabbageworm and cabbage looper) appear mid-season, feeding from leaf edges inward and leaving ragged holes. Hand-pick egg clusters from leaf undersides; apply Bt (Bacillus thuringiensis) if populations build. These pests slow significantly once temperatures drop below 55°F, so fall crops generally have lighter pressure.
Bacterial leaf spot causes dark, water-soaked lesions with yellow halos. Water at soil level only, avoid overhead irrigation, and rotate brassicas out of the same bed every year.
Bolting: Both types bolt in sustained heat above 80°F. Lacinato has slightly lower heat tolerance than most curly kale cultivars and goes to flower more readily in a hot June. For spring plantings, choose early-maturing cultivars (Starbor at 55 days, Red Russian at 50 days) and harvest aggressively before heat sets in.
For the full zone-by-zone planting calendar, companion planting pairings, and detailed pest management, see our complete kale growing guide.
Which Should You Grow?
Here’s the direct version, without hedging:
| If you want… | Choose this type |
|---|---|
| Sweet, tender leaves for raw salads and pasta | Dinosaur kale (Lacinato or Dazzling Blue) |
| A kale that overwinters in zones 3–5 | Curly kale (Winterbor or Meadowlark) |
| The easiest leaf to wash and prep | Dinosaur kale |
| Structure in soups and braises | Curly kale |
| Dramatic color change with cold | Redbor (curly) or Dazzling Blue (lacinato) |
| Maximum flavor after frost | Both — harvest in October after weeks of cool nights |
| Freezer-friendly bulk harvest | Curly kale (holds texture better after blanching) |
The most practical answer for most home gardeners is to plant a few of each. They peak at different moments, serve different kitchen purposes, and together give you kale worth eating from early spring through the first hard freeze. With 3–4 plants of each type, a 4×8-foot bed produces more kale than most families can eat fresh — with enough to freeze for winter.
Frequently Asked Questions
Can dinosaur kale and curly kale cross-pollinate?
Yes — they’re the same species (Brassica oleracea) and will cross if both are allowed to flower at the same time. This matters only if you’re saving seeds. For eating, grow them side by side without any concern.
When does kale taste best after a frost?
Both types are at their peak after several weeks of sustained cool weather in the 35–41°F range, not after a single frost event. The sugar accumulation that drives sweetening builds gradually during cold acclimatization. Mid-October through November harvests in most US growing zones deliver the best flavor.
Is dinosaur kale harder to grow than curly kale?
Not meaningfully harder. The main practical difference is cold tolerance: in zones 5 and colder, lacinato needs row covers or a cold frame to survive hard winters. Curly kale varieties like Winterbor need no protection. Soil, sun, water, and fertilizer requirements are the same for both.
How do you know when dinosaur kale is ready to harvest?
The outer (lowest) leaves are ready at full size — typically 8–12 inches long and a deep blue-green. Baby greens are ready at 25–30 days from seed. Leaves should feel firm and look glossy; yellowed or limp leaves are past their best and should be removed to encourage new growth from the center.
Sources
1. NC State Extension Gardener Plant Toolbox — Brassica oleracea Lacinato Kale Group (plants.ces.ncsu.edu)
2. NC State Extension Gardener Plant Toolbox — Brassica oleracea Kale Group (Curly Kale)
3. Utah State University Extension — Kale in the Garden
4. WVU Extension — Growing Kale in West Virginia
5. Gardener’s Path — How to Grow Lacinato (Dinosaur) Kale
6. University of Oldenburg — How kale is affected by cold temperatures (uol.de)
7. PubMed — Frost effects on phytochemical content and sensory properties of curly kale
8. PubMed — Effects of photoperiod, growth temperature and cold acclimatization on glucosinolates, sugars and fatty acids in kale
