Plum Tomato
An oval, thick-walled tomato bred for paste-making, canning, and sun-drying due to its low moisture content.
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Meet Plum Tomato
An oval, thick-walled tomato bred for paste-making, canning, and sun-drying due to its low moisture content. Plants produce clusters of uniform, medium-sized fruits that are easy to process in large batches. Determinate varieties are available that ripen most fruit at once for efficient canning operations. Provide calcium-rich soil to prevent blossom end rot on the elongated fruits.
When to plant Plum Tomato
Start plum tomato seeds indoors 6-8 weeks before the last frost. Plant one-quarter inch deep at 75-85°F for germination in 7-10 days. Provide strong light for 14-16 hours daily. Pot up when true leaves develop, burying stems deeply. Harden off for 10-14 days before transplanting when nighttime temperatures stay above 50°F. Plant deeply in the garden. For bulk canning, plant multiple plants of one variety for uniform ripening. Both San Marzano and Roma types are widely available and produce true-to-type from saved seed.
Your Plum Tomato Year
Composed for Zone 7 · typical seasons · frost passes Apr 2, returns Nov 1
Sow Plum Tomato Mar – May, pick Jul – Sep. Set your climate below and every date on this plate re-times itself.
How to grow Plum Tomato
Plum tomatoes, also called paste or Roma-type tomatoes, produce oval, thick-walled fruits specifically bred for making sauce, paste, canning, and sun-drying. Their low moisture content and few seeds mean more concentrated tomato flavor per fruit. Plants come in both determinate and indeterminate types. Start seeds indoors 6-8 weeks before the last frost. Transplant after soil reaches 60°F.
Space plants 18-24 inches apart for determinate varieties or 24-30 inches for indeterminate types. Determinate plum tomatoes produce their entire crop within a concentrated 2-3 week period, ideal for bulk canning. Indeterminate types produce continuously. Water with 1-1.5 inches per week, reducing slightly as fruits ripen to concentrate flavors. Mulch to maintain even soil moisture.
Plum tomatoes are among the most productive tomato types, with determinate plants producing 20-30 pounds per plant in a concentrated harvest. The thick walls and low juice content make them the most efficient type for processing. They are less prone to cracking than round tomatoes and handle well during harvest and transport. For paste making, the concentrated flesh reduces cooking time significantly compared to slicing tomatoes.
8 plants fit a 4 × 8 ft bed
Each Plum Tomato wants 60 cm of elbow room. The planner keeps that spacing for you — every plant, every bed.
Plum Tomato's best neighbours
Plum tomatoes benefit from basil planted nearby for pest deterrence and potential flavor improvement. Marigolds repel nematodes. Carrots and parsley make good companions at ground level. For bulk production, dedicated rows of plum tomatoes with basil between plants make efficient use of garden space. Borage attracts pollinators. Avoid fennel and brassicas. In intensive production gardens, interplant with garlic and onions which deter many tomato pests.
Basil belongs beside it. Cabbage doesn't.
Old growers' knowledge, checked against Plum Tomato's real companion table below — test any plant you're growing.
Related growing guides
Feed it well
Plum tomatoes grow well in fertile, well-drained soil with a pH of 6.2-6.8. Incorporate compost before planting. Apply balanced fertilizer at transplanting and switch to phosphorus-rich feed when flowering begins. For bulk production, consistent fertility is important; side-dress with compost every 3-4 weeks. Calcium supplementation prevents blossom end rot. Avoid excessive nitrogen late in the season which delays ripening of the concentrated harvest. Rich, deep soil supports the heavy fruit loads these productive plants carry.
Ideal Temperature
Hardiness Zone Compatibility
From seed to harvest, stage by stage
Seed Starting
Seeds germinate in warm conditions, sending up a pale stem with two smooth, rounded cotyledon leaves. Plum tomato seeds require consistent moisture and warmth of 21-27°C (70-80°F) for reliable germination within 5-10 days. The initial root system develops quickly in loose, sterile seed-starting mix.
Seedling Development
True leaves emerge with the characteristic serrated, slightly fuzzy tomato foliage. Stems thicken and develop fine hairs that can eventually root if buried. Seedlings grow steadily under strong light, building the root mass needed for transplant success.
Vegetative Growth
After transplanting outdoors, plants grow rapidly in warm soil and full sun. Determinate plum varieties like Roma develop a bushy, compact habit reaching 90-120 cm, while indeterminate types like San Marzano continue growing taller throughout the season. The extensive root system can extend 60-90 cm deep.
Flowering and Fruit Set
Clusters of small yellow star-shaped flowers appear at stem nodes. Plum tomatoes are self-pollinating — pollen transfers within each flower through wind vibration or bee visits. Fruit set is optimal when daytime temperatures stay between 21-29°C (70-85°F); temperatures above 35°C (95°F) cause blossom drop.
Fruit Development
Green fruits swell into the characteristic elongated, oval shape unique to plum tomatoes. The thick pericarp walls develop as seed cavities remain small — this is the trait that makes plum tomatoes superior for cooking. Fruits transition from pale green to a deepening red as lycopene accumulates.
Harvest Season
Ripe plum tomatoes turn a deep, uniform red and yield slightly to gentle pressure. Determinate varieties like Roma ripen most of their fruit within a concentrated 3-4 week window — ideal for canning and sauce-making marathons. Indeterminate varieties produce continuously until frost.
Start seeds indoors 6-8 weeks before your last frost date. Sow 6mm deep in moist seed-starting mix and cover trays with humidity domes. Bottom heat from a seedling mat dramatically improves germination speed and uniformity.
Caring for Plum Tomato month by month
What to do each month for your Plum Tomato
July
You are hereFlowering intensifies and first green fruits form. Maintain consistent, deep watering to prevent blossom end rot — the most common plum tomato problem. Watch for hornworms, aphids, and early signs of blight. Apply calcium foliar spray if blossom end rot appears.
Know exactly what to do in your garden — every month
One email at the start of each month: what to sow, plant, and tackle right now — for your Plum Tomato and everything growing around it. Plus a short starter course that helps you dodge the classic mistakes.
- What to do, right now
- Matched to your season
- Starter course included
Harvesting Plum Tomato
Harvest plum tomatoes when fruits are uniformly deep red and firm with a slight give to pressure. For sauce and canning, allow fruits to fully ripen on the vine for maximum flavor concentration. Determinate varieties ripen most of their crop within a 2-3 week window, perfect for batch processing. Pick every 2-3 days during peak harvest. Cut from the vine with a short stem attached. For sun-drying, harvest at peak ripeness when sugar and acid content are highest. Each plant can produce 20-30 pounds or more of processing-quality tomatoes.
assuming you sow when the window opens — set your real date
Pick Plum Tomato promptly and the plant keeps producing.
Storage & Preservation
Fresh plum tomatoes keep at room temperature for about one week. Their primary value lies in preservation. For sauce, cook down with garlic, onions, and herbs; the low moisture content means shorter cooking time than slicing tomatoes. Make tomato paste by spreading strained sauce on baking sheets and oven-drying until thick. Can as crushed, diced, or whole peeled using water-bath canning with proper acidification. Sun-dry or oven-dry halved fruits for intense, chewy preserved tomatoes. Freeze whole for easy winter sauce making.
What goes wrong — and the fix
Early Blight
DiseaseBrown target-like spots on lower leaves, progressing upward and causing defoliation.
Fusarium Wilt
DiseaseYellowing and wilting starting on one side, brown discoloration in stem vascular tissue.
Tomato Hornworm
PestLarge caterpillars consuming foliage and occasionally damaging fruits.
Blossom End Rot
DiseaseDark, leathery patches on the blossom end of fruits, common during rapid growth periods.
Troubleshooting Common Problems
Blossom end rot affects plum tomatoes, especially San Marzano types, more than some other varieties. Consistent watering is essential. Determinate varieties produce a concentrated harvest that requires readiness for bulk processing; plan your canning and preserving schedule in advance. Cracking is generally less common than in round tomatoes but can occur with inconsistent watering. Fusarium wilt resistance varies by variety; choose resistant types marked with F or VF for problem gardens. Late blight can be devastating; remove infected plants immediately.
Growing Tips
- Bury transplants deep — very deep. Remove the lower two-thirds of leaves and bury the bare stem up to the remaining foliage. Every buried node sprouts new roots, creating a massive root system that produces a stronger, more drought-resistant, and higher-yielding plant.
- Choose between determinate and indeterminate carefully based on your goals. Determinate varieties like Roma ripen most fruit at once — perfect for sauce-making and canning days. Indeterminate types like San Marzano produce steadily over months — better for continuous fresh use.
- Water consistently and deeply at the base, never overhead. Inconsistent watering is the primary cause of blossom end rot, the most common plum tomato affliction. Drip irrigation or soaker hoses on a timer deliver the steady moisture plum tomatoes demand.
- Rotate tomato planting locations every 3-4 years without exception. Soilborne diseases like Fusarium wilt, Verticillium wilt, and bacterial canker build up in soil where tomatoes are planted repeatedly. Avoid planting where any nightshade family crops (peppers, eggplant, potatoes) grew recently.
- Prune suckers on indeterminate plum tomatoes to maintain one or two main stems. This concentrates the plant's energy into fewer but larger, better-flavored fruit clusters and improves air circulation that reduces fungal disease pressure.
- Apply calcium before planting to prevent blossom end rot. Work crushed eggshells, gypsum, or lime into the planting hole. Once blossom end rot appears on fruit, it cannot be reversed — prevention through consistent watering and adequate soil calcium is the only solution.
- Remove the lowest 30 cm of foliage once plants are well established. Leaves touching or near the soil are the primary entry point for early blight and other fungal diseases. This simple pruning step dramatically reduces disease pressure.
- For the best sauce flavor, let plum tomatoes ripen fully on the vine until they are deep red and just slightly soft. Early-picked tomatoes develop less sugar and lower lycopene content. If you must pick early for weather reasons, ripen at room temperature — never refrigerate unripe tomatoes.
Pick your Plum Tomato
San Marzano
The gold standard for sauce and canning. Elongated fruits with sweet, complex flavor and minimal seeds. Indeterminate.
Roma VF
Classic determinate paste tomato with excellent disease resistance and concentrated harvest. Reliable and productive.
Amish Paste
Large heirloom paste tomato with rich, sweet flavor and dual-purpose use for fresh eating and processing.
Juliet
Elongated grape-type hybrid with excellent crack resistance and sweet flavor. Very heavy yields over a long season.
Opalka
Polish heirloom with elongated fruits and almost no seed cavities. Exceptionally meaty flesh ideal for drying and paste.
A plum tomato plant costs $3-5 as a transplant or mere pennies when grown from seed, yet produces 4-10 kg of fruit per season. With fresh plum tomatoes selling for $3-6 per kg at grocery stores and farmers markets, each plant returns $12-60 in produce value. The savings multiply dramatically when you consider that a 700ml jar of quality San Marzano canned tomatoes costs $4-7 at the store, while 6-8 homegrown plants yield enough to can 20-30 jars of superior sauce for the cost of jars and lids alone — a potential savings of $80-200 per season for families who regularly cook with tomato sauce.
Quick recipes
Classic Marinara Sauce
45 minA rich, slow-simmered Italian tomato sauce that showcases why plum tomatoes are the world's preferred sauce variety. Their low moisture and thick flesh cook down into a concentrated, velvety sauce with minimal effort and no need to drain excess liquid.
9 ingredientsOven-Roasted Plum Tomatoes
50 minSlow-roasting transforms plum tomatoes into intensely sweet, caramelized jewels that elevate pasta, bruschetta, salads, and grain bowls. The low moisture content of plum tomatoes means they roast perfectly without turning watery.
7 ingredientsFresh Bruschetta with Plum Tomatoes
15 minA vibrant Italian appetizer where diced plum tomatoes are the star — their meaty texture and low juice content keep the bread crisp instead of soggy, making them far superior to slicing tomatoes for this classic dish.
8 ingredientsCulinary Uses
Plum tomatoes are the world's preferred processing tomato. Make classic Italian tomato sauce by slow-cooking with garlic, olive oil, and basil. The thick flesh produces rich, full-bodied sauce without hours of reducing. Core, blanch, peel, and can whole or crushed for year-round pantry supply. Halve and slow-roast for intensely flavored oven-dried tomatoes. Make genuine tomato paste by cooking and straining into a thick concentrate. Fresh plum tomatoes are also excellent diced for bruschetta, chopped into salads, and sliced for sandwiches with minimal drip.
What's inside
Health Benefits
- Plum tomatoes are one of the richest dietary sources of lycopene, a carotenoid antioxidant linked to reduced risk of prostate cancer, cardiovascular disease, and age-related macular degeneration — and cooking actually increases lycopene bioavailability by 2-3 times compared to raw fruit.
- High in vitamin C, supporting immune function, collagen synthesis for skin and joint health, and enhancing the absorption of non-heme iron from plant-based foods when eaten together.
- Excellent source of vitamin A as beta-carotene, essential for maintaining healthy vision, supporting immune cell production, and promoting skin cell turnover and repair.
- Contains potassium (237mg per 100g), a mineral critical for maintaining healthy blood pressure, proper heart rhythm, and balanced fluid levels — most adults do not consume enough potassium daily.
- Rich in the antioxidants lutein and zeaxanthin, which accumulate in the retina and protect against harmful blue light and oxidative damage that contributes to cataracts and macular degeneration.
- Provides vitamin K and small amounts of calcium, working together to support bone mineralization and reduce the risk of osteoporosis, particularly important for postmenopausal women.
Where Plum Tomato comes from
The plum tomato traces its ancestry to the wild tomato species Solanum pimpinellifolium of western South America, particularly the coastal deserts and Andean foothills of Peru and Ecuador. Indigenous peoples of Mesoamerica domesticated the tomato long before European contact, selecting for larger fruit size and diverse shapes including the elongated forms that would become modern plum varieties. When Spanish conquistadors brought tomatoes to Europe in the early 16th century, the fruit was initially regarded with suspicion in most of the continent — but southern Italy embraced it enthusiastically.
The volcanic soils around Naples and the Campania region proved ideal for tomato cultivation, and Italian farmers began selecting for the oval, thick-walled fruits that cooked down into superior sauces. By the 18th century, the plum-shaped tomato had become the foundation of Neapolitan cuisine, and the San Marzano variety — named for the small town near Mount Vesuvius where it was perfected — emerged as the gold standard for canned tomatoes and sauce production. The mineral-rich volcanic soil, warm Mediterranean climate, and centuries of careful seed selection created a variety with unmatched sweetness, low acidity, and dense flesh.
In the 20th century, agricultural research programs developed modern plum tomato varieties optimized for different growing conditions and uses. The USDA released the Roma tomato in 1955, breeding it for disease resistance, uniform ripening, and mechanical harvesting — it quickly became the world's most commercially important plum variety. Today, plum tomatoes are grown on every inhabited continent, from backyard gardens to vast commercial operations. Italy, the United States, China, and Turkey are the largest producers. The plum tomato remains the undisputed king of the processing tomato world, accounting for the majority of canned tomatoes, tomato paste, and commercial sauces produced globally.
Plum Tomato: did you know?
Fascinating facts about Plum Tomato
Plum tomatoes — particularly the San Marzano variety grown in the volcanic soil near Mount Vesuvius — are so prized in Italy that genuine San Marzano tomatoes carry a DOP (Protected Designation of Origin) certification, and counterfeits are a significant problem in the global canned tomato market.
Plum Tomato questions, answered
When should I plant Plum Tomato?
What are good companion plants for Plum Tomato?
What hardiness zones can Plum Tomato grow in?
How much sun does Plum Tomato need?
How far apart should I space Plum Tomato?
What pests and diseases affect Plum Tomato?
How do I store Plum Tomato after harvest?
What are the best Plum Tomato varieties to grow?
What soil does Plum Tomato need?
What is the difference between Roma and San Marzano tomatoes?
Why are my plum tomatoes getting black spots on the bottom?
Can I grow plum tomatoes in containers?
How do I preserve plum tomatoes for winter?
Why are my plum tomato plants flowering but not setting fruit?
When is the best time to harvest plum tomatoes for making sauce?
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From the “When to plant” sectionDrag-and-drop bed planner
Design beds on a grid. Every plant snaps to its proper spacing, and you can see your whole season laid out before you spend a cent on seed.
From the “Growing guide” sectionCompanion conflicts, caught early
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From the “Companions” sectionReminders you'll actually act on
“Water the beans.” “Pick today before it turns.” Timely, specific, and tied to the plants you're really growing.
From the “Harvest” sectionSuccession, scheduled
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From the “When to plant” sectionA record that gets smarter
Every harvest you log teaches it your garden. Next year's plan starts from what actually worked in your soil, not a textbook's.
From the “Overview” sectionPlant these alongside Plum Tomato
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