Blue tomato plant

Plant Profile & Key Characteristics

Overview: A short-lived tender perennial almost always grown as an annual, forming a soft-stemmed bush or vine 0.5–3 m (1.5–10 ft) tall depending on cultivar and type. It is grown for its edible fruit, which is eaten fresh and cooked into sauce and juice.

Quick Specifications

Specification	Attribute
Plant Type / Life Cycle	Tender perennial grown as an annual
Foliage Type	Herbaceous, evergreen while growing (frost-killed)
Mature Size	0.5–3 m (1.5–10 ft)
Growth Rate	Fast to moderate
Root System	Taproot developing extensive fibrous roots; stems readily form adventitious roots where they touch soil
Toxicity	Fruit edible; the foliage and green parts contain solanine and are toxic if eaten
Hardiness	USDA zones 11+ as a perennial; grown as a warm-season annual from zone 2+

Growth Form & Structure

• Height & Spread: Reaches 0.5–3 m (1.5–10 ft) in the ground; dwarf and determinate cultivars stay much smaller and the compact ones grow well in pots and, with the right variety, even on a sunny windowsill.
• Growth Habit & Form: Soft-stemmed plant grown either as a self-topping bush (determinate) or as an indeterminate vine that keeps climbing and cropping and needs staking or caging.
• Lifespan & Maturity: Fruiting begins about 1–2.5 months after transplanting, with harvest roughly 55–160 days from sowing; the plant is spent after one season in most climates.

Anatomy & Physical Features

• Leaves & Foliage: Green, pinnately divided, aromatic leaves; plants are either the serrated regular-leaf type or the smooth, broad-lobed potato-leaf type.
• Fruit Profile: Anthocyanin-rich blue fruit, often flushed with red, green or pink; round, elliptic or cherry-sized.

Primary Uses & Landscape Value

• Edible Uses: Eaten fresh in salads and cooked down into sauce, paste and juice, and preserved in many forms.
• Functional & Ornamental Roles: A staple vegetable-garden and container crop; compact bush types also suit patio pots and hanging baskets.

Care Guide: Planting, Soil & Watering

Overview: Tomatoes are warm-season plants that crop best in full sun and rich, nutrient-packed, well-draining soil. They are frost-tender and need steady moisture, so keep the soil evenly moist and feed the plant through the growing season.

Quick Care Requirements

Requirement	Ideal Condition
Planting Season	In spring after the last frost (zones 2–10a); spring to summer in 10b–11a; spring to autumn in 11b; year-round in zone 12+
Growth Rate	Moderate to fast
Soil Type	Rich, nutrient-packed, organic and well-draining
Soil pH	6.0–6.8 (slightly acidic to neutral)
Water Need	Moderate to high; keep the soil evenly moist

Planting & Establishment

• Best Planting Season: Plant out in spring once the last frost has passed and the soil has warmed; in warm, frost-free zones (10b–11a) plant from spring into summer, in zone 11b spring through autumn, and year-round from zone 12.
• How to Plant:
  • Hole Preparation: Dig a hole wider and a little deeper than the root ball so the roots can spread into loose soil.
  • Soil Amendments: Mix in plenty of organic matter, dead leaves and humus, then backfill with some of that enriched soil.
  • Planting Depth: Tomatoes root along their stems, so you can set the plant a few centimetres deeper than it grew in the pot; firm gently and add a support or cage at planting time.
• Growth Speed & Expectations: A quick, vigorous grower reaching about 0.5–3 m depending on cultivar; feed and add organic matter if growth is slow, and provide trellising or a cage as it climbs.

Soil, Watering & Drainage Care

• Soil Mix & Drainage Needs: Give it a well-ventilated, free-draining soil rich in organic matter; in containers (about 10–30 L) use a quality potting mix, avoid a saucer that traps water, and mulch to keep the root zone evenly moist.
• Watering Schedule & Technique:
  • Young / Newly Planted: Water twice on planting day, then daily for the first couple of weeks while the roots establish.
  • Established: Water regularly and deeply to keep the soil consistently moist; mulch, especially in summer, to hold moisture and steady the supply.
  • Seasonal Adjustments: Water more in summer heat and less in cool weather; protect the plant from winter cold, which damages or kills it in all but frost-free zones.

Climate, Light & Hardiness

Blue tomato is a warm-season crop – a tender perennial in frost-free climates but grown almost everywhere as a frost-sensitive annual – suited to tropical, subtropical, Mediterranean, temperate and desert summers. It needs full sun and warmth, and the site rates it at hardiness zone 11 and warmer as a perennial, zone 10b with careful overwintering, and zone 2 and warmer grown as an annual.

Quick Climate Specifications

Climate Zones	Tropical, subtropical, Mediterranean, temperate, desert (warm season)
USDA Hardiness Zones	11 and warmer as a perennial; 10b with overwintering; 2 and warmer grown as an annual (site data)
Optimal Temp Range	21–26°C (70–79°F); workable roughly 10–32°C (50–90°F) (site data)
Cold Damage Begins	Chilling injury and stalled growth below about 10°C (50°F)
Approx. Survival Minimum	Frost kills the plant at about 0°C (32°F)
Frost Tolerance	None
Light Conditions	Full sun

Sunlight & Light Exposure

Optimal Light Setup

Full sun – at least six to eight hours – is needed for strong growth and heavy fruiting, and it also drives the blue skin colour: the anthocyanin pigment develops where the fruit is directly struck by sun, so well-lit fruit colour up most deeply. Plants grow in less sun but set fewer, paler fruit.

Shade & Heat Management

In intense, high-sun climates the same exposed fruit can sunburn, so in the hottest regions some afternoon shade or leaf cover protects the fruit while still allowing good colouring. Training the plant at a slight angle helps expose fruit without scorching it.

Temperature Extremes & Hardiness

USDA Hardiness & Regional Limits

Lifecycle and hardiness are separate: it is a tender perennial in frost-free climates (zone 11 and warmer, or zone 10b with protection) yet grown as an annual almost everywhere else because frost ends it. It can be carried over by keeping cuttings indoors through winter and replanting after the last spring frost.

Cold Damage & Winter Protection

Growth stalls and chilling injury begins below about 10°C (50°F), and frost near 0°C (32°F) kills the plant. In zone 10b it may survive a mild winter with protection and set a little winter fruit, but it is not reliably winter-hardy.

Extreme Heat Tolerance

The plant handles heat, but fruit set is the weak point: sustained high temperatures (roughly above 32–35°C / 90–95°F, especially with warm nights) cause flowers to drop and fruit set to fail until it cools. Steady warmth around 21–26°C (70–79°F) gives the best set and quality.

Frost-Free Growing Season

The frost-free window is the key planning factor: fruit ripens roughly 55–160 days from sowing, so plant out after the last spring frost and, in short-summer regions, start early indoors and choose the warmest, most sheltered site.

Wind, Humidity & Microclimate

Wind Tolerance

Low. Tall, brittle, fruit-laden stems break easily, so staking or caging and a sheltered position matter in windy gardens.

Microclimate Recommendations

A warm, sheltered, sunny spot extends the season in cooler regions. Container root-zones heat and cool faster than open ground, so guard against overheating in summer and move pots out of cold snaps.

Growing this plant in a greenhouse

A greenhouse can give blue tomato plant frost protection, cold protection, a longer growing season and controlled production. Under warm enough conditions it can keep growing well beyond the normal outdoor season and potentially be maintained year-round — though continuous cropping is not guaranteed and depends on temperature and light.

Greenhouse at a glance

Greenhouse suitability	Excellent — a major practical advantage
Main benefits	frost protection, cold protection, a longer growing season, controlled production
Season extension	potentially year-round
Outdoor protection advisable below	about 10°C
Maintain greenhouse minimum	around 10°C for active growth
Suitable types	heated greenhouse, polycarbonate greenhouse, lean-to
Heating	Heating is recommended in cold climates for continuous growth.

Related greenhouse guides

• Greenhouses: How to Choose the Right Greenhouse
• Best Greenhouse Heaters
• Greenhouse Climate Control: Temperature, Ventilation and Humidity
• Best Lean-To Greenhouses

Growing in Pots, Balconies & Indoors

The blue tomato is an excellent container and balcony plant but not a true houseplant – indoors the light is too weak unless it sits on a very sunny sill. In a large, free-draining pot it crops heavily on a patio or balcony.

Quick Details

• Container Size: 10-30 L (2-6 gal), depending on the cultivar
• Indoor Suitability: Not a deep-indoor houseplant; a compact cultivar can fruit on a bright, sunny windowsill
• Best Spot: Full sun – a warm, south-facing balcony or patio is ideal (it fruits in a little less light, just less heavily)
• Soil & Drainage: Well-ventilated, organic-rich mix (potting mix, or peat/coir with perlite or vermiculite); must drain freely
• Watering in Pots: Keep the soil evenly moist – pots dry fast; let water drain away and never leave it waterlogged

Indoors & On the Windowsill

• Houseplant limits: It will not thrive deep in a room – the light is simply too weak for a fruiting plant.
• Windowsill growing: Choose a compact or dwarf cultivar and a sunny sill with direct sun; there the plant and its fruit get enough light, as the grower notes.
• Overwintering: In frost-free conditions it can be carried over as a short-lived perennial; where winters are cold, bring a potted plant under cover before the first frost.
• Safety: The ripe fruit is edible, but the leaves, stems and unripe fruit are toxic if eaten – keep the foliage out of reach of children and pets indoors.

On a Balcony or Patio

• Light & wind: Give it the sunniest spot; on an exposed balcony, stake or cage it and shelter it from wind. Walls and paving reflect heat, so pots dry quickly – check moisture daily in warm weather.
• Practicalities: A full 10-30 L pot is heavy once watered – make sure the balcony can take the weight and that drainage runoff will not be a nuisance below.

Choosing the Pot, Soil & Long-Term Care

• Pot & drainage: A 10-30 L pot with strong drainage holes; the grower advises against standing it in a saucer of water, so let it drain freely and avoid root rot. Terracotta breathes and dries faster, while glazed or plastic pots hold moisture longer.
• Potting mix: Well-ventilated and organic-rich – potting mix, or peat with perlite or vermiculite.
• Feeding: Potted plants need feeding more often than those in the ground, as nutrients wash out with each watering – a balanced feed, easing off high nitrogen once flowers and fruit set.
• As a perennial (frost-free climates): every two years refresh the mix and lightly prune the root ball and the top growth.

Grower’s Container Tip

• Gradual fill: Start the pot with only about 10% soil; as the roots fill it, keep topping up until it is full – this buries more stem and builds a stronger root system.

Fruit & Uses

This tomato is grown for its edible fruit, eaten fresh or cooked. The fruit is the only edible part – the leaves and stems of the tomato plant are toxic and must not be eaten.

Quick Edible Specs

Edible Parts	Fruit only
Main Use(s)	Culinary – eaten fresh, cooked, made into sauce or juice
Eaten Raw or Cooked	Both – raw or cooked
Preparation Required	None beyond washing; do not eat leaves or stems
Harvest Season	Ripe fruit roughly 55–160 days from sowing (about 1–2.5 months from planting)
Storage	Can be picked slightly early and ripened indoors
Safety/Toxicity Caveat	Only the ripe fruit is edible; the leaves, stems and green parts contain toxic alkaloids (Solanaceae)

Fruit

The fruit is blue – the anthocyanin-rich skin colours up where it catches the sun – and can be combined with red, green or pink; the shape can be round, elliptic or cherry. The fruit is ready when it has fully coloured up and softens slightly, and it is picked by hand. If pests attack the crop, pick the fruit before it is fully ripe and let it finish ripening at home. Cultivars include: Indigo Rose (dark blue-purple-black), Azul (blue-purple, regular size), OSU Blue (blue skin, red-blue inside), Indigo tomato and Cherry Blue (small blue cherry).

Harvesting

Fruit ripens roughly 55–160 days from sowing, or about 1–2.5 months from planting. Pick when the fruit has reached its full colour and gives slightly to gentle pressure; tomatoes will also continue to ripen off the vine, so they can be harvested a little early.

Preparation, Uses & Safety

Wash the ripe fruit and use it fresh, cooked, or made into sauce or juice. No special detoxing is needed for the ripe fruit. Safety: only the ripe fruit should be eaten – the plant’s leaves, stems and unripe green parts contain toxic alkaloids typical of the nightshade family and are not food.

Bloom & Flower Guide

Quick Details

• Bloom Season: Through the warm, frost-free months; nearly continuous only in frost-free climates
• Time to First Bloom: About 15 to 80 days after planting, depending on the cultivar and warmth
• Flower Appearance: Small, yellow, star-shaped flowers borne in clusters (trusses)
• Edibility: Not eaten – the ripe fruit (covered in its own section) is the edible part, while the flowers and green parts contain mild alkaloids and are not used as food

Detailed Blooming Overview

Tomato flowers are self-fertile: each little yellow star has both male and female parts, so the plant is largely self-pollinating. Wind and buzz-pollinating bees – which vibrate the pollen loose – improve set. The flowers open in clusters, and each pollinated bloom becomes a fruit.

Flower Characteristics

• Small, yellow, star-shaped flowers.
• Carried in clusters (trusses) along the stems.

Bloom Care & Thinning

• Pollination & fruit set: Flowers are self-pollinating and also visited by bees; wind or a gentle shake of the plant helps set fruit in still air, and even flowers that look ‘blown’ can often be shaken lightly to set.

Bloom Health & Protection

• Blossom drop: Tomatoes commonly shed flowers without setting in very hot nights, cold snaps, or when pollination is poor – steady moisture, shelter from temperature extremes, and helping pollination with a gentle daily shake hold more blooms.

Pests, Diseases & Troubleshooting

Overview: The Blue tomato plant (Solanum lycopersicum) is a heavy-feeding annual that attracts a wide range of chewing and sap-sucking pests and is highly susceptible to soil-borne and foliar diseases, especially in warm, humid, crowded conditions. The best defence is cultural: crop rotation, resistant varieties, good spacing and airflow, mulching, and prompt removal of affected leaves — with organic sprays used only when monitoring shows they are needed.

Quick Troubleshooting Overview

Issue / Pest	Main Symptom	Primary Solution
Tomato/tobacco hornworm	Whole leaves and stems stripped fast; dark frass pellets	Hand-pick; encourage parasitic wasps; Bt
Aphids & whiteflies	Sticky honeydew, sooty mould, curled shoots; virus spread	Rinse, soap/neem, reflective mulch, beneficials
Fruitworm / hornworm on fruit	Boreholes into green and ripening fruit	Monitor, hand-pick, Bt on young larvae
Early & late blight	Target-ring or greasy grey-brown leaf/fruit lesions	Rotate, space, remove leaves, copper fungicide
Fusarium/Verticillium wilt	One-sided yellowing and wilting; browned inner stem	Resistant (VFN) varieties, rotation, rogue plants
Blossom-end rot	Sunken black leathery patch on fruit base	Even watering, mulch, correct calcium/pH

Common Pests & Management

• Tomato & tobacco hornworm (Manduca quinquemaculata / M. sexta):
  • Symptoms: Large green caterpillars with a tail horn that defoliate stems overnight and gouge fruit; look for dark green-black frass pellets below the damage before you spot the well-camouflaged larva.
  • Prevention & Control: Inspect and hand-pick (drop into soapy water); leave caterpillars carrying white wasp cocoons in place, as those parasitoids do free control. Encourage lacewings and wasps, and spray Bacillus thuringiensis (Bt) on young larvae if needed.
• Aphids (Macrosiphum euphorbiae, Myzus persicae):
  • Symptoms: Clusters of soft green, pink or black insects on shoot tips and leaf undersides, causing curl, honeydew and sooty mould; they transmit several viruses.
  • Prevention & Control: Blast off with water, encourage ladybirds, lacewings and hoverflies, use reflective/silver mulch to deter them, and spot-treat with insecticidal soap or neem oil.
• Whiteflies (Bemisia tabaci, Trialeurodes vaporariorum):
  • Symptoms: Tiny white moth-like insects that fly up in clouds when disturbed; honeydew, sooty mould, yellowing and virus transmission follow.
  • Prevention & Control: Hang yellow sticky traps, use reflective mulch, encourage Encarsia parasitoids, and treat undersides with insecticidal soap or neem, especially in greenhouses.
• Tomato fruitworm / corn earworm (Helicoverpa zea):
  • Symptoms: Caterpillars bore neat holes into green and ripening fruit near the stem, causing internal rot and secondary spoilage.
  • Prevention & Control: Monitor with pheromone traps, hand-pick, encourage Trichogramma egg parasitoids, and apply Bt or spinosad to young larvae before they enter fruit.
• Spider mites (Tetranychus urticae):
  • Symptoms: Fine yellow stippling, a dusty bronzed look, and fine webbing on leaf undersides in hot, dry weather.
  • Prevention & Control: Keep plants well watered and not dusty, rinse foliage, release predatory mites, and use insecticidal soap or horticultural oil for outbreaks.
• Flea beetles & Colorado potato beetle (Epitrix spp., Leptinotarsa decemlineata):
  • Symptoms: Flea beetles pepper leaves with tiny shot-holes (worst on seedlings); the striped Colorado beetle and its red grubs chew foliage heavily.
  • Prevention & Control: Use floating row cover on young plants, hand-pick beetles and egg clusters, rotate crops away from other nightshades, and use kaolin clay or spinosad if pressure is high.
• Root-knot nematodes (Meloidogyne spp.):
  • Symptoms: Stunting, wilting and yellowing despite good care, with knotty galls swelling the roots.
  • Prevention & Control: Plant nematode-resistant (N-coded) varieties, rotate with non-hosts, add organic matter, and solarise or grow marigold cover in badly infested beds.

Diseases & Fungal Issues

• Early blight (Alternaria solani):
  • Symptoms: Dark brown spots with concentric target rings and a yellow halo on lower, older leaves first, working upward; can cause stem lesions and fruit rot.
  • Treatment & Management: Rotate crops, mulch to stop soil splash, stake for airflow, remove affected lower leaves, and use a copper or biofungicide preventively in humid spells.
• Late blight (Phytophthora infestans):
  • Symptoms: Greasy grey-green blotches on leaves with white mould underneath in cool wet weather, plus firm brown fruit rot; spreads and kills plants very fast.
  • Treatment & Management: Grow resistant varieties, space and ventilate well, avoid overhead watering, remove and destroy infected plants immediately, and apply copper preventively when conditions favour it.
• Septoria leaf spot (Septoria lycopersici):
  • Symptoms: Many small circular spots with dark borders and grey centres on lower leaves, causing heavy leaf drop.
  • Treatment & Management: Remove infected leaves, mulch, water at the base, rotate, and use copper if it spreads.
• Fusarium & Verticillium wilt (Fusarium oxysporum, Verticillium spp.):
  • Symptoms: Yellowing and wilting that often starts on one side or lower leaves; cutting the stem reveals brown streaking in the vascular tissue. Soil-borne and long-lived.
  • Treatment & Management: There is no cure — choose VF-resistant varieties, rotate for several years, remove and destroy affected plants, and avoid replanting nightshades in the same soil.
• Bacterial spot & speck (Xanthomonas / Pseudomonas syringae):
  • Symptoms: Small dark greasy spots, sometimes with yellow halos, on leaves and fruit, worst in warm wet weather.
  • Treatment & Management: Use clean/treated seed, avoid overhead watering and handling wet plants, rotate, and apply copper preventively.
• Viruses (Tomato mosaic, Tomato spotted wilt, curly top):
  • Symptoms: Mottled, distorted or fern-like leaves, ringspots, bronzing and stunted uneven growth; no recovery.
  • Treatment & Management: Control aphids, thrips and whiteflies that spread them, remove infected plants, wash hands and tools (tobacco mosaic spreads by touch), and choose resistant varieties.

Growing Difficulties & Abiotic Problems

• Blossom-end rot:
  • Cause & Symptoms: Uneven watering and calcium delivery (not simply low soil calcium) cause a sunken, leathery black patch on the blossom end of the fruit.
  • Correction Strategy: Water evenly and deeply, mulch to buffer moisture, keep soil pH near 6.5, and avoid heavy nitrogen swings.
• Fruit cracking & catfacing:
  • Cause & Symptoms: Sudden water surges after dry spells split ripening fruit; cold at flowering causes scarred, misshapen (catfaced) fruit.
  • Correction Strategy: Keep moisture steady, harvest promptly, and avoid setting fruit in cold snaps.
• Blossom drop & poor set:
  • Cause & Symptoms: Extreme heat or cold, excess nitrogen, or poor pollination cause flowers to drop without fruiting.
  • Correction Strategy: Balance feeding, shade in extreme heat, and gently shake plants or encourage pollinators to aid pollen set.
• Sunscald:
  • Cause & Symptoms: Fruit over-exposed after leaf loss develops pale, papery, sunken burned patches.
  • Correction Strategy: Keep healthy leaf cover, avoid heavy pruning in strong sun, and control the diseases that defoliate plants.
• Leaf roll & nutrient issues:
  • Cause & Symptoms: Upward leaf rolling from heat/moisture stress; yellowing between veins from magnesium/iron shortfalls; purpling from cold or phosphorus lock-up.
  • Correction Strategy: Water consistently, feed a balanced fruiting fertiliser, correct pH, and warm the root zone in cold soils.

What Helps — Products & Tools

For the Blue tomato plant the practical kit is: Bacillus thuringiensis (Bt) and spinosad for caterpillars, insecticidal soap and neem/horticultural oil for aphids, whiteflies and mites, yellow and reflective mulches/sticky traps for flying pests, and copper or biofungicide plus resistant (VFN) varieties, crop rotation and mulch for the blight and wilt complex. Even watering, calcium/pH correction and good airflow prevent most of the non-pest problems.

Fertilizing & Feeding

A moderate feeder: nitrogen supports early leafy growth, then a potassium-leaning balanced feed favors fruit set and a steady harvest.

Quick Fertilizing Specs

Feeding Level	moderate
young_feeding	A balanced start with organic matter as transplants establish.
mature_feeding	Shift toward potassium with modest nitrogen once flowering and fruiting begin.
Main Nutrient Priority	Nitrogen for early growth, then potassium-leaning balanced feeding for fruiting.
Best Feeding Period	From transplant through fruit set and the harvest period.
Organic Options	Compost and well-rotted manure build fertile soil and feed steadily.
Soil pH	Slightly acidic to near neutral suits tomatoes.
Reduce/Stop Feeding	Taper feeding as the plant finishes cropping at the end of the season.

Feeding by Growth Stage

Transplant and establishment

Help young transplants settle in and build roots before rapid growth.

Nutrient direction	A complete, balanced fertilizer plus plenty of organic matter to feed steady early growth.
Timing	At and just after transplanting into warm soil.
Frequency	A modest starter feeding as plants establish.
Fertilizer types	A balanced complete vegetable fertilizer, Compost or well-rotted manure worked into the bed
Precautions	Do not overdo nitrogen early; rich soil and a balanced start are enough for young plants.

Vegetative growth

Build a strong, leafy framework of stems and foliage before heavy fruiting.

Nutrient direction	A nitrogen-forward complete fertilizer to drive vigorous leaf and stem growth.
Timing	During active vine and leaf growth before flowering takes over.
Frequency	Regular, moderate feeding through the growth phase.
Fertilizer types	A complete vegetable fertilizer with a nitrogen emphasis, Compost or organic matter to sustain growth
Precautions	Keep nitrogen moderate — too much delays flowering and gives leafy plants with little fruit.

Flowering, fruiting and harvest

Support flowering, fruit set and a long, steady harvest.

Nutrient direction	Shift to a lower-nitrogen, potassium-leaning complete fertilizer to favor fruit over more leaves.
Timing	From first flowering through the fruiting and harvest period.
Frequency	Steady, regular feeding maintained while the plant is cropping.
Fertilizer types	A complete vegetable fertilizer with a potassium emphasis and modest nitrogen, A balanced complete fertilizer supplemented as fruit load builds
Precautions	Feed evenly and water consistently; erratic feeding and watering trigger fruit problems such as blossom end rot.

Nutrient Deficiency Signs & Corrections

Older, lower leaves turn pale green to yellow and the plant grows slowly and spindly.

Possible causes	Low nitrogen in the soil, Nutrients leached by heavy watering or rain, Cold soil slowing uptake early in the season
Appears first on	Older, lower leaves
What to check	Recent feeding history, Soil organic matter and drainage, Soil temperature early in the season
Possible correction	Side-dress with a nitrogen-containing complete fertilizer and enrich the soil with organic matter.

Interveinal yellowing on older leaves, with the veins staying green.

Possible causes	Low magnesium in the soil, High potassium competing with magnesium uptake, Acidic, leached soils
Appears first on	Older, lower leaves
What to check	Soil test for magnesium, Fertilizer potassium balance, Soil pH
Possible correction	Correct soil pH and apply a magnesium source per its label; keep potassium from being excessive.

Sunken, dark, leathery patch at the blossom end of the fruit.

Possible causes	Uneven or inconsistent watering disrupting calcium movement, Rapid growth outpacing calcium uptake, Damaged or restricted roots
Appears first on	Blossom end of developing fruit
What to check	Watering consistency and mulch, Rate of growth and root health, Whether feeding has been erratic
Possible correction	Water evenly and mulch to steady soil moisture; it is chiefly a water and calcium-uptake issue, not solved by more fertilizer.