How to Grow Cucumber
'Marketmore 76' from Seed
The heritage slicer with a story — an open-pollinated heirloom developed at Cornell University in 1976, still one of the most disease-resistant slicing cucumbers available; dark green 20–23cm fruits with a crisp, mild flavour, seeds that can be saved year after year, and nearly fifty years of home garden performance to recommend it
In 1976, Dr Henry Munger of Cornell University released a new cucumber variety that represented the culmination of decades of breeding work: Marketmore 76, an open-pollinated slicing cucumber with exceptional disease resistance, reliable uniform dark-green fruits, and excellent flavour. In the nearly fifty years since, dozens of newer F1 hybrid varieties have been developed and marketed — and Marketmore 76 remains a fixture in home vegetable gardens worldwide, continuing to be selected and saved by gardeners who value what open-pollinated heritage varieties offer that hybrids cannot: the ability to save seed from the best fruits each year, to grow a variety that has decades of performance data rather than a single season's trial results, and the connection to a long tradition of plant breeding that produced something genuinely excellent.
The growing method for Marketmore 76 is essentially the same as for any cucumber — warm start indoors, rich prepared soil, consistent watering, regular harvest. The key differentiators from the F1 Burpless variety are the open-pollinated nature (seeds can be saved and will breed true), the comprehensive disease resistance package, and the character of the fruit itself — slightly darker, slightly more substantial, with a classic slicing cucumber flavour rather than the Japanese-influenced "burpless" character of F1 varieties.
Quick Facts at a Glance
Type
Open-pollinated heritage; outdoor or greenhouse
Origin
Cornell University, 1976 — Dr Henry Munger
Fruit
20–23cm; dark green; crisp; classic slicing flavour
Disease resistance
Powdery mildew · downy mildew · cucumber mosaic virus
Seed saving
Open-pollinated — save seeds from best fruits each year
Difficulty
3 out of 5 — straightforward with warm conditions
Understanding the Variety
The Cornell Story — Why Marketmore 76 Still Matters
Dr Henry Munger spent his career at Cornell University developing disease-resistant vegetable varieties for home gardeners and small-scale growers. The Marketmore series — of which '76 is the most widely grown iteration — was developed to address the cucumber diseases that routinely devastated home garden crops: cucumber mosaic virus, powdery mildew, and downy mildew. By incorporating resistance to all three into a single open-pollinated variety with excellent eating quality, Dr Munger produced something that has outlasted the fashions of successive decades of vegetable breeding. The "76" refers to the year of release; earlier versions (Marketmore, Marketmore 70) preceded it, and later ones (Marketmore 80, 97) followed — but '76 remains the benchmark of the series.
Open-Pollinated vs F1 — Why It Matters for Seed Saving
Marketmore 76 is open-pollinated — its seeds, when saved from a well-grown fruit, will produce plants identical to the parent in the following season. This is the defining characteristic of heirloom and heritage varieties, and the reason they can be maintained, selected, and improved by gardeners rather than requiring a new purchased packet each year. To save seed: allow one or two fruits to fully mature on the vine (they will turn orange-yellow and become very large). Cut the mature cucumber, scoop out the seed pulp into a jar of water, ferment for two to three days (the viable seeds sink), rinse, and dry thoroughly on kitchen paper. Store in a labelled paper envelope in a cool, dry place. Viability typically lasts two to three years.
⚠️ Keep Both Male and Female Flowers — Same Rule as All Outdoor Cucumbers
Marketmore 76, like all outdoor cucumber varieties, produces separate male and female flowers and requires insect pollination. Do not remove male flowers. Female flowers have a tiny embryonic cucumber behind the petals; male flowers attach directly to the stem. Both must be present for fruits to develop. Hand-pollinate in cool or wet weather when bees are less active.
Sowing & Growing On
Sow on Edge — and Use Biodegradable Pots if Available
Sow cucumber seeds on their edge (1–2cm deep) to prevent tip-rot during germination. For Marketmore 76 specifically, consider using biodegradable coir pots or paper modules — cucumbers dislike root disturbance at planting time, and a biodegradable pot that can be planted directly into the ground minimises transplant shock and accelerates establishment.
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Sow indoors April–early May, on edge, 1–2cm deep at 20–22°C. One seed per small biodegradable pot or module. Germination in 7–10 days. Grow on in bright conditions at 15–18°C after germination. Protect from harsh direct sunlight during the first two weeks — seedlings scorch easily.
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Prepare rich planting positions with compost well before planting out. Dig a planting hole 30cm deep and wide at each position, incorporate 2–3 shovelfuls of well-rotted compost or manure, and backfill. Water well and allow to settle. Erect support — cane structure, trellis, or fence — before planting. Marketmore 76 vines reach 1.5–2m.
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Harden off and plant out late May–June after all frost. Harden off over 7–10 days. Plant biodegradable pot and all, minimising root disturbance. Space 60–90cm apart in full sun. Water in well. Cover with fleece for the first week if nights remain cool.
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Water consistently, feed weekly with high-potash fertiliser from flowering. Consistent moisture is essential — drought stress causes bitterness and reduced yield even in this disease-resistant variety. Begin feeding with a tomato-type fertiliser every 7–10 days when the first flowers open. Continue until harvest ends.
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Harvest at 20cm every 2–3 days — leave a few to mature for seed saving. Cut fruits with scissors or a knife. Do not twist. Pick at 20cm for best eating quality. If seed saving, leave one or two fruits on the healthiest plant until they turn orange-yellow and feel very heavy — these are the seed fruits.
Growing On & Care
Disease Resistance in Practice
The practical value of Marketmore 76's disease resistance package becomes apparent in a wet UK summer. Where susceptible varieties develop cucumber mosaic virus (causing mottled, distorted leaves and stunted plants) or succumb to mildews in August, Marketmore 76 continues cropping with only the late-season cosmetic mildew that affects all cucumbers eventually. This reliability in adverse conditions is why it remains a trusted choice for UK gardeners nearly fifty years after its introduction.
Training and Structure
Train the main stem up the support structure, tying every 20–30cm. Pinch out the main growing tip when it reaches the top of the support (approximately 1.5–2m). Allow side shoots to develop and bear fruit — these are the most productive parts of the plant. Pinch side shoot tips at 60cm to encourage further branching. The resulting framework produces a productive, well-managed plant through August and September.
Eating Marketmore 76
The dark-green, slightly bumpy skin of Marketmore 76 is thicker than the thin-skinned Japanese burpless types — some gardeners prefer to peel it, others eat it as-is. The flesh is crisp, mild, and refreshing — the classic slicing cucumber flavour that has made this variety a home garden staple for decades. It pickles exceptionally well at small size (6–8cm): halve lengthways and pack into white wine vinegar with dill seed, mustard seed, and black peppercorns for a simple refrigerator pickle ready in 24 hours.
Outdoor vs Greenhouse
Marketmore 76 succeeds in both environments with the same growing method. Outdoors: expect harvest from August to October in a reasonable UK summer. Under glass: harvest begins earlier (late June or July) and continues longer, producing higher total yields from each plant. In the greenhouse, hand-pollinate daily during flowering — bee access is less reliable under glass. Two plants per growbag or 60cm apart in the greenhouse border.
Companion Planting
Traditional cucumber companions include: borage (attracts pollinating bees and is said to improve cucumber flavour and vigour), nasturtiums (attract aphids away from cucumbers as a sacrificial trap crop), and marigolds (deter whitefly and other pests in the greenhouse). Avoid planting near aromatic herbs or brassicas, which may inhibit cucumber growth. Cucumbers grow well alongside courgettes, tomatoes, and sweetcorn in terms of soil requirements and spacing logic.
Seed Saving for Next Year
Select one or two fruits on the healthiest, most productive plant. Leave on the vine until they turn yellow-orange and become heavy (approximately 6–8 weeks after the normal harvest stage). Cut and scoop seed pulp into water. Ferment for 2–3 days at room temperature — viable seeds sink, hollow or infertile seeds float. Pour off the water and floating debris, rinse seeds thoroughly, and spread on kitchen paper to dry completely before storing in a labelled paper envelope.
Sowing & Harvest Calendar
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
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| 🌱 Sow indoors |
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| 🌿 Plant out |
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| 🥒 Harvest |
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Common Problems & Solutions
| Problem | Likely Cause | What to Do |
|---|---|---|
| No fruits forming | Male flowers removed; insufficient pollinators | Keep all male flowers (thin-stemmed, no swelling behind bloom). Hand-pollinate daily in cool or wet weather by touching a fully open male flower to each open female flower. Both flower types must be present and accessible to insects (or hand-pollination) for fruit to set. |
| Cucumber mosaic virus symptoms (mottled, distorted leaves) | Virus spread by aphids; unlikely in Marketmore 76 | Marketmore 76 has built-in resistance to cucumber mosaic virus — if symptoms appear, check that the correct variety has been grown. Control aphids promptly on surrounding plants. Remove and dispose of any severely affected plants. Do not save seed from virus-affected plants. |
| Fruits bitter | Water stress; irregular watering; over-mature | Water consistently and deeply — never allow soil to dry completely between waterings. Harvest at 20cm before fruits become large and begin to turn yellow. Unlike the burpless F1, Marketmore 76 can develop some bitterness at the stalk end in stressed conditions — peel if this occurs. |
| Saved seeds not germinating next year | Seeds not fully dried; stored in damp/warm conditions | Seeds must be completely dry before storage — spread on kitchen paper for at least a week in warm conditions before sealing in paper envelopes. Store in a cool (below 15°C), dry, dark location. Check viability by placing a few seeds on damp kitchen paper — if 70%+ germinate within 10 days, the batch is viable. Marketmore 76 seed typically remains viable for 2–3 years under good storage conditions. |
Plant Specifications
The heirloom that outlasted every hybrid that tried to replace it — nearly fifty years of reliable performance
Marketmore 76 has been grown in home gardens worldwide since 1976 not through brand loyalty or marketing but because it performs reliably, resists the diseases that devastate less robust varieties, produces crisp and flavourful dark-green fruits, and — uniquely among cucumbers — allows its seeds to be saved each year and grown again the following season. Sow in April in biodegradable pots, prepare rich soil, keep both male and female flowers, harvest every two to three days from August, and save seed from the best fruit for next year. The simplest form of continuity in the vegetable garden.
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