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How to Grow Red Ursa

Red Ursa

Solanum lycopersicum 'Red Ursa'

vegetable

Red Ursa is a determinate (bush) tomato variety bred for disease resistance and productivity in challenging conditions. It produces medium-sized, deep red fruits with excellent flavor and is notably resistant to late blight, making it ideal for humid or disease-prone climates. This variety is particularly valued by gardeners seeking reliable yields without extensive fungicide applications.

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Example Red Ursa timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Red Ursa

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Red Ursa

    Around Jun 26

    ≈ 70 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Red Ursa dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours minimum daily (8+ hours preferred for best fruit production)
💧
Water: Consistent moisture; water deeply 1-1.5 inches per week, adjusting for rainfall. Water at soil level to minimize foliar wetness and reduce disease pressure. Avoid overhead watering.
📏
Spacing: 24 inches
📅
Days to maturity: 70-85 days from transplant
🌱
Planting depth: Bury stems up to the first true leaves; roots will form along buried stem

Soil

Type: Well-draining loamy soil rich in organic matter
pH: 6.0-6.8
Amendments:
compost aged manure perlite or coarse sand for drainage balanced fertilizer or tomato-specific blend

Growing Zones

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Thrives in zones 4-9; cold hardy for a tomato, can succeed in zone 3 with season extension

3a 3b 4a 4b 4c 5a 5b 5c 6a 6b 6c 7a 7b 7c 8a 8b 8c 9a 9b 10a

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Growth Stages

1

Seedling

2-3 weeks

Tiny plants with cotyledons and first true leaves emerging; pale green color

Provide 14-16 hours of bright light daily under grow lights or in a sunny window. Keep soil moist but not waterlogged. Maintain 70-75°F. Begin fertilizing with diluted fertilizer once true leaves appear.

2

Vegetative (Pre-transplant)

3-4 weeks

Plants develop multiple sets of true leaves and robust stems; 6-8 inches tall when ready to transplant

Pot up seedlings into larger containers as needed. Gradually harden off by exposing to outdoor conditions for increasing durations over 7-10 days. Maintain consistent moisture and adequate light.

3

Establishment (Post-transplant)

2-3 weeks

Newly transplanted seedlings focusing on root establishment; slower leaf growth during first 1-2 weeks

Plant deep, burying lower stem. Water thoroughly at planting. Mulch around base (2-3 inches) while keeping stem clear. Avoid fertilizing for first week; moderate fertilizer application thereafter. Support with stakes or cages early.

4

Flowering & Early Fruiting

3-4 weeks

Yellow flowers appear in clusters; small green fruits begin developing; plant reaches full height (3-4 feet for determinate type)

Continue consistent watering, especially critical during fruit set. Apply balanced fertilizer every 2-3 weeks or use slow-release formula. Watch for early blight and late blight; remove lower leaves if spotted. Prune suckers minimally on determinate varieties.

5

Fruit Maturation & Harvest

3-4 weeks to full maturity; continues if weather permits

Fruits enlarge and ripen from green to deep red; plant may show natural decline in foliage as a determinate type

Maintain even moisture to prevent crack-ing and blossom-end rot. Reduce nitrogen fertilizer; shift to higher potassium if possible. Monitor closely for late blight—Red Ursa is resistant but not immune. Remove diseased foliage promptly. Begin harvesting at first blush of red.

Companion Planting

Plan your garden →

Plant with:

basil parsley carrot onion garlic borage marigold nasturtium

Avoid planting near:

brassicas (cabbage, broccoli) fennel dill potatoes other nightshades

Common Pests

  • Hand-pick large caterpillars; use Bacillus thuringiensis (Bt) for smaller infestations; encourage parasitoid wasps

  • Use yellow sticky traps; spray neem oil or insecticidal soap; encourage natural predators like ladybugs

  • Increase humidity; spray with water to dislodge; use miticide if severe; neem oil can help

  • Spray with water; use insecticidal soap; neem oil; encourage beneficial insects

  • Remove affected lower leaves; improve air circulation; mulch to prevent soil splash; apply copper fungicide if needed; practice crop rotation

  • Red Ursa is bred with partial resistance; remove diseased foliage immediately; avoid overhead watering; ensure good drainage and air flow; copper or chlorothalonil fungicide as preventive if conditions favor disease

Uses

🍳

Fresh slicing and cooking

Culinary

Red Ursa tomatoes offer excellent flavor suitable for fresh slicing in salads, salsas, and sandwiches, as well as for cooking in sauces and soups. The firm flesh holds up well during cooking. [source]

🍳

Sauce and paste production

Culinary

These tomatoes are ideal for making homemade tomato sauce, paste, and ketchup due to their deep red color and good sugar content. [source]

💊

Heart and antioxidant health

Medicinal

Red tomatoes contain lycopene and other antioxidants associated with cardiovascular health and anti-inflammatory benefits. Regular consumption may support overall wellness. [source]

🏠

Disease-resistant home gardening

Household

Red Ursa is bred specifically for late blight resistance, reducing the need for fungicide applications and making it an excellent choice for organic and sustainable home gardening, especially in humid climates. [source]

🦋

Pollinator and beneficial insect support

Wildlife

Tomato flowers attract bees and other pollinators, and the plant structure provides habitat for beneficial insects that control pests naturally. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begin harvesting when fruits show first blush of red color at the blossom end; they will continue ripening off the vine. Gently twist and lift, or cut stem if picking resistance is high. Harvest all remaining fruit before first frost. Green tomatoes can ripen indoors in a paper bag with a ripe banana or in a well-lit window.

Fun Facts

  • 🌱 Red Ursa was developed specifically to resist late blight (Phytophthora infestans), the pathogen that caused the Irish Potato Famine; its breeding incorporates genetic resistance traits from wild tomato relatives.
  • 🌱 As a determinate (bush) variety, Red Ursa concentrates most of its fruit production in a shorter window, making it ideal for canning and sauce production all at once, rather than spreading harvest throughout the season.
  • 🌱 The deep red color of Red Ursa indicates high lycopene content, a powerful antioxidant that becomes more bioavailable when tomatoes are cooked or processed, making homemade sauce especially nutritious.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Full Sun Mulch Sucker Transplant True Leaves
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