Variety field guide
What to expect from Carbon
Carbon tomato seeds produce purple slicing tomato fruit up to about 1 lb or more on indeterminate plants reaching 61–72 in; maturity is 70-79 Days.
Read the complete product descriptionTraits, flavor, garden use, variety notes, and the full catalog record
Carbon tomato seeds grow into indeterminate plants reaching 61–72 in, bearing purple fruit up to about 1 lb or more. This slicing tomato is especially suited to fresh slicing, sandwiches, and salads. Maturity is 70-79 Days from transplanting.
About Carbon
Carbon is a slicing tomato grown as Solanum lycopersicum L. Plants have an indeterminate habit and reach 61–72 in; support is listed as stake. The principal mature or market color is Purple, with fruit described as up to about 1 lb or more. Reproductive classification: Open-Pollinated (OP). Maturity: 70-79 Days. Names associated with this variety include Tomato, Tomato Seeds - Indeterminate - Carbon Beefsteak.
- Scientific name:Solanum lycopersicum L.
- Life cycle:Annual
- Planting season:Spring
- Growth habit:Indeterminate
- Plant height:61–72 in
- Sunlight:Full sun
- Seed depth:1/8 in
- Germination:6–12 Days at 75–90 °F
- Spacing:30 in between plants; 36 in between rows
- Soil:Loamy; pH 6.0–6.5
- Water:Moderate
- Support:Stake
- Reproductive type:Open-Pollinated (OP)
- Fruit:Purple; Up to about 1 lb or more
History and seedkeeping context
Cornell records Carbon as an early- to main-season heirloom with indeterminate plants and flat-oblate purplish-red fruit. Cornell records Carbon as an heirloom tomato. Carbon Beefsteak Tomato Seeds belongs to the long record of tomato selection that began with domestication in the Americas and continued through farmers, gardeners, public breeders, market growers, and seedkeepers.
Where a precise breeder or family chain is not supported by a primary record, this page does not invent one. The variety is described through observable fruit, plant habit, use, and the records kept by people who continue to grow it. Carbon is an heirloom tomato on indeterminate plants.
Fruit, flavor, and kitchen use
Carbon is best for fresh slicing, sandwiches, and salads. The expected flavor is rich, savory, complex tomato flavor with balanced sweetness and acidity. Fruit is described as purple and up to about 1 lb or more. Use a tested current recipe for home canning; cultivar name alone does not establish safe acidity. Carbon is especially useful for fresh slicing, sandwiches, and salads. Flavor and eating quality are described as rich, savory, complex tomato flavor with balanced sweetness and acidity. For home canning, use a tested current recipe; cultivar name, color, or perceived sweetness does not establish safe acidity.
How to grow Carbon
Start Carbon indoors about 6 to 8 weeks before the last expected frost. Sow 1/8 in deep in a warm, evenly moist seed-starting mix; expect 6–12 Days near 75–90 °F. Give seedlings strong light, move them into larger cells before they become root-bound, and harden them gradually before planting outside after frost danger.
Plant in full sun with loamy soil near pH 6.0–6.5. Space plants 30 in apart and rows 36 in apart. Maintain moderate moisture, mulch after the soil warms, and keep foliage off wet soil where possible. Set up stake at transplanting. The indeterminate plant reaches 61–72 in.
Season care
• Give Carbon strong light from emergence so seedlings remain stocky rather than stretched. • Install stake when transplanting; adding support after vines are large can damage roots and stems. • Water at the soil line and maintain even moisture to reduce cracking, blossom-end rot risk, and stress-related fruit problems. • Harvest when the fruit has reached its cultivar-specific color and gives slightly to gentle pressure; color alone can be misleading on green, purple, or striped varieties. • Use 70-79 Days as a planning range rather than a guaranteed calendar date; weather and transplant stress can shift first harvest.
Harvest and maturity
70-79 Days from transplanting under suitable conditions. Harvest when the cultivar-specific color has developed and the fruit gives slightly to gentle pressure; green-ripe, striped, purple, and dark cultivars require more than a simple red-color test.
Saving seed
Tomatoes are primarily self-pollinating, but occasional crossing can occur. To maintain Carbon, save seed from several healthy true-to-type plants and bag unopened flower clusters when extra isolation is needed. Allow labeled fruit to ripen fully, squeeze the seed and gel into a container, ferment briefly until the gel releases, rinse clean, and dry the seed in a thin labeled layer. Store the finished lot cool and dry with the year, source, plant count, and isolation notes.
Common questions
When is Carbon ready?
Plan around 70-79 Days. The listed range is a planning guide, and weather, transplant stress, and harvest stage can shift the actual date.
How long does germination take?
Expect 6–12 Days near 75–90 °F. Cooler media, excess water, old seed, or uneven moisture can delay emergence.
How large does it grow?
Expect about 61–72 in. Growth habit: Indeterminate. Support: Stake.
How is it used?
Fresh slicing, sandwiches, and salads
Can I save seed?
Tomatoes are primarily self-pollinating, but occasional crossing can occur.
