Kale vs Spinach: Leaves plus Growing Season plus Harvest
Kale vs spinach is a common question for cool season gardeners. Both are leafy greens that grow in spring plus fall. Kale is a larger, longer lived plant picked leaf by leaf. Spinach is a small, fast crop that bolts once days grow long plus warm.
The short answer
Kale is a big, cold hardy plant spaced about 12 inches apart. You pick its outer leaves over a long season. Spinach is small, spaced about 3 inches apart plus ready fast. It bolts in long, warm days, so sow it early in spring or again in late summer.
How do kale and spinach leaves differ?
Kale comes in several leaf types. NC State Extension describes Improved Dwarf Siberian with dark green, frilly leaves. Red Russian has purple stems plus flat leaves. Toscano has long, thin, puckered dark green leaves.
Spinach leaves form a low rosette. University of Illinois Extension notes spinach comes in crinkled plus plain leaved types. Crinkled leaves tend to catch soil during rain. Utah State University Extension notes spinach comes in a range of leaf types plus textures.
Which handles cold and heat better?
Kale is the hardier plant. Utah State University Extension notes young kale is not seriously damaged down to 25°F. Mature plants can withstand very cold temperatures. Kale can stay in the garden through winter.
Spinach is less cold hardy as a seedling. Young plants handle temperatures down to 32°F. Both crops grow most vigorously below 75°F. High summer heat reduces growth plus quality for both. Spinach also bolts quickly in the long days of late spring or summer.
| Trait | Kale | Spinach |
|---|---|---|
| Plant spacing | 12 inches | 3 inches |
| Row spacing | 2 feet | 12 inches |
| Seed depth | ¼ to ½ inch | ½ inch |
| Young plant cold limit | 25°F | 32°F |
| Spring planting | 4 to 5 weeks before last frost | 2 to 3 weeks before last frost |
| Fall maturity | 2 to 3 weeks after first frost | 1 to 2 weeks after first frost |
Source: Utah State University Extension.
How is each harvested?
Kale is harvested when leaves reach full size. Strip the older outer leaves first so young leaves continue to grow. NC State Extension notes mature leaves are ready 50 to 75 days after seeding. Baby greens are ready 20 to 30 days after seeding.
Spinach leaves can be picked any time before the flower stalk forms. Utah State University Extension notes all leaves can be cut to within 2 inches of the soil if the growing point is not damaged. University of Illinois Extension advises harvesting the whole crop when seed stalks begin to form.
How to: step by step
- Prepare fertile, well drained soil rich in organic matter.
- Sow kale 4 to 5 weeks before the last frost.
- Sow spinach 2 to 3 weeks before the last frost.
- Thin out kale to 12 inches plus spinach to 3 inches.
- Supply 1 to 2 inches weekly.
- Pick kale leaf by leaf plus harvest spinach before it bolts.
Troubleshooting
Spinach flowers early: long, warm days. Sow early in spring plus pick slow bolting varieties.
Leaves turn tough: uneven moisture. Water deeply plus mulch to steady soil moisture.
Gritty spinach leaves: crinkled leaves catch soil. Plant a plain leaved variety.
For related reading see cannabis leaf anatomy, frost damage on cannabis plus raised beds for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- How to grow kale in your garden, Utah State University Extension
- Kale, NC State Extension
- Spinach, home vegetable gardening, University of Illinois Extension
- Spinach in the garden, Utah State University Extension
FAQ
Can kale and spinach grow together?
Yes, they share a season. Both are cool season greens that prefer fertile, well drained soil rich in organic matter. Utah State University Extension spaces kale 12 inches apart in rows 2 feet apart. Spinach goes 3 inches apart in rows 12 inches apart. Plan bed space around those different plant sizes.
Which is easier to grow?
Each has a challenge. Spinach is fast growing plus not susceptible to many problems, per Utah State University Extension. Yet it bolts in long, warm days, so timing matters. Kale tolerates more cold plus yields for months. It needs more space plus steady moisture so leaves do not turn tough.
How cold hardy is kale?
Very hardy. Utah State University Extension notes young kale plants are not seriously damaged by temperatures down to 25°F. Mature plants are extremely hardy plus can withstand very cold temperatures. Many gardeners leave kale growing in the garden through winter. Plan fall kale to mature 2 to 3 weeks after the first fall frost.
When should spinach be planted?
Plant it in spring plus again in late summer. Utah State University Extension advises sowing ½ inch deep 2 to 3 weeks before the last spring frost. Spinach seed can be sown after soil reaches 40°F. University of Illinois Extension suggests chilling seed for 1 to 2 weeks before summer or fall plantings.
Why does spinach bolt?
Day length plus heat. University of Illinois Extension notes spinach bolts quickly to seed during long days in late spring or summer. Warm temperatures speed this up. Varieties called long standing or slow to bolt suit spring planting. Harvest the whole crop when seed stalks begin to form, since leaves decline as flowering starts.
