annual vegetable
Parris Island romaine lettuce
Best in spring and fall; summer heat can make leaves bitter.
Growing Profile
- Hardiness
- Zones 3a-10a
- Sun
- FullPartial
- Soil
- Loam
- Water
- Medium
- Planting depth
- Sow 0.1-0.3 in deep
- Container min
- 1+ gal (good)
- Goals
- Vegetables & herbs
Harvest & Use
- Window
- crisp romaine heads in cool weather
- Yield return
- 0.5-1 lb/plant/season
- First output
- 45-85 days
- Best for
- Vegetables & herbs
Harvest window: crisp romaine heads in cool weather. Once established, the current pound-return model uses 0.5-1 lb/plant/season with a harvest window of 6-12 weeks.
Plant photos
What it looks like in the garden
Use these photos to compare the plant's leaves, stems, flowers, fruit, and overall habit before you buy or plant.
Photos show a representative plant in the garden. Fruit color, size, and growth habit can vary by cultivar, season, nursery stock, and site.
Photo sources: Leon Brooks / Wikimedia Commons (Public domain)
Quantitative Profile
- Pound return
- 0.5-1 lb/plant/season
- 10-year return
- 5-10 lb/10 yrs
- Full output
- This season
- Mature size
- 0.5-1 ft H x 0.5-1 ft W
- Spacing
- 0.5-1 ft in-row x 1-3 ft rows
- Planting depth
- Sow 0.1-0.3 in deep
- Container min
- 1+ gal (good)
- Productive life
- 1 yrs
- Difficulty
- 2/5
- Reliability
- 3/5
- Data quality
- Medium profile, Low yield confidence
Pound return is the stock-style yield metric. These are planning ranges for comparing plants, not guarantees. Cultivar, rootstock, climate, soil, pruning, pest pressure, and wildlife can move actual results.
Planting Checklist
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Right-size container with drainage
Containers / Before plantingUse a container large enough for mature roots, with open drainage holes to prevent root rot.
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Expanding container potting mix
Containers / Before plantingUse a lighter container medium instead of dense garden soil in pots and grow bags.
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Seed-starting trays
Propagation / Pre-seasonStart annual vegetables, herbs, and flowers ahead of transplant season.
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Floating row cover
Protection / At plantingProtect young crops from wind, light frost, and early pest pressure while still letting light and water through.
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Shade cloth
Protection / Heat wavesReduce heat stress for cool-season greens, tender transplants, and containers in hot sun.
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Seedling grow light
Propagation / Pre-seasonKeep indoor seedlings compact and sturdy before they move outside.
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Balanced garden fertilizer
Nutrition / During growthFeed annual vegetables, herbs, flowers, and hungry container crops according to soil or label guidance.
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Soil test kit or lab mailer
Site prep / Before plantingCheck pH and baseline nutrients before adding amendments, especially for fruiting crops, native beds, and acid-loving plants.
Yield curve
Estimated Pound Return
Projected annual yield ramp from establishment to full production, using the current sourced range for Parris Island romaine lettuce.
- Year 1
- 0.5-1 lb First-year estimate from the sourced curve.
- Year 5
- 0.5-1 lb
- Year 10
- 0.5-1 lb
- 10-year total
- 5-10 lb/10 yrs
Shaded band shows the sourced low-to-high pound-yield range. The line tracks the midpoint for quick comparison.
Method: head-count range converted to pounds for return comparison. Annual crops assume one comparable planting per year; perennial crops ramp from first bearing to full production.
Planting Strategy
- Planting depth: Sow 0.1-0.3 in deep
- Container minimum: 1+ gal (good). Small herbs, leafy crops, and radishes work in 1+ gal pots or wider shallow planters.
- Start with one plant when testing fit in a new bed or container.
- Plant more than one when harvest volume or pollination is the main goal.
- Use the pairing map below to choose nearby companions or compatible varieties.
Risk Factors
- Match the site first: full, partial light, loam soil, and medium water.
- Use 0.5-1 ft in-row x 1-3 ft rows as the first spacing model; adjust for hedges, trellises, containers, or local guidance.
- Plan around mature size: 0.5-1 ft H x 0.5-1 ft W.
- For harvest planning, treat "crisp romaine heads in cool weather" and 1 head/plant/season as planning ranges, not guarantees.
- Local drainage, pests, chill hours, wildlife pressure, and microclimates can change the result.
Related Planning Guides
Comparable Plants
Companion Plants & Pairings
Plant Nearby
Fast cool-season crops can share spring or fall bed space before heat-loving plants take over.
Use it: Use this as a timing strategy: harvest greens and radishes before peas shade them or before summer crops need the bed.
Sources & Methodology
This guide combines hardiness range, light, soil, water, harvest timing, traits, source listings, plant relationships, and quantitative planning metrics. Pairings are screened for practical garden fit.
Quantitative values use extension and botanical-reference ranges where available. For less-studied cultivars, similar crops fill gaps conservatively. Ranges are intentionally broad so the profile stays useful without pretending to be exact.
Quantitative sources: UGA Extension - Growing Vegetables OrganicallyCornell Cooperative Extension - Recommended Spacing and Expected Yield for Garden VegetablesUniversity of Maine Extension - Planting Chart for the Home Vegetable GardenUniversity of Maryland Extension - Types of Containers for Growing VegetablesIllinois Extension - Growing Vegetables in Containers
Affiliate listing: Amazon. Search links are not paid placements unless explicitly marked; affiliate listings may earn a commission. Last reviewed: 2026-05-24.