Thompson Seedless Grape
Vitis vinifera 'Thompson Seedless'
fruitThompson Seedless is the worlds best-known table grape and the classic raisin grape, producing long clusters of small pale-green berries that turn golden when fully sun-ripened. The Vitis vinifera variety is sweet, crisp, and seedless, making it the gold standard for fresh eating, drying, and homemade raisins.
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Sun
full sun
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Water
Every 5 days
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Harvest
~24 months
to first harvest
📊
Difficulty
medium
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Lifecycle
perennial
Comes back every year
↔️
Spacing
8 ft in row, 10 ft between rows
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Planting Depth
Same depth as nursery; bud union just above soil
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Soil pH
6.0-6.5
Growing Details
Soil Type
Average, well-draining
Hardiness Zones
Zones 6 – 10
When to Fertilize
Light feed in early spring as buds swell
Fertilizer
10-10-10 at 2 oz per vine in planting year, then by soil test
🌱 Growing Guide
Plant in full sun on deep well-drained soil. Hardy in zones 7 to 10; Thompson needs a long warm growing season and does poorly in cool damp climates. Set vines 8 ft apart in rows 10 ft apart with the crown at the same depth as the nursery. Train to a 2-wire trellis with the lower wire at 3 ft and the top wire at 5.5 ft. Prune hard each winter to a four-cane Kniffin system or a single cordon; Thompson is prone to overcropping, which reduces sugar.
Planting Calendar
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Direct sow
Apr 15
🌾
Projected first harvest
Aug 23 · Year 3
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Year 1
✅ Plant alongside
Good neighbors that attract beneficial insects or deter pests
- Hyssop — Improves grape vine vigor and may help repel cabbage moths and aphids
- Chives — Sulfur compounds may suppress fungal disease pressure around the trunk
- Yarrow — Hosts predatory wasps and hoverflies that hunt leafhoppers and mealybugs
- White Clover — Living mulch in the aisles that fixes nitrogen and supports beneficial insects
❌ Keep away from
Cabbage
🛡️ Pest & disease prevention
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Open canopy with summer leaf-pulling around fruit zones, weekly sulfur sprays during humid weather, and full-sun siting
Grape berry moth
Hang pheromone traps to time controls; remove cluster-feeding larvae by hand
Hand-pick into soapy water; floating row cover when feasible
Rake fallen leaves and mummies, prune for airflow, and apply protective fungicides at bloom and post-bloom in wet years
🌾 Harvest & storage
Thompson Seedless ripens in September. Sample berries before harvest; grapes do not ripen after picking, so wait for full sweetness. Cut whole clusters with pruners; bunches keep in the fridge for 1 to 2 weeks. To make raisins, lay clusters in a single layer on screens in the sun for 2 to 3 weeks, or dehydrate at 135F for 24 to 36 hours.
🥗 Nutrition & benefits
About 69 calories per 100 g with 0.9 g fiber, 4 mg vitamin C, and 191 mg potassium. Thompson Seedless also supplies resveratrol and quercetin, two polyphenols studied for cardiovascular benefits.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.