Roma tomato
Solanum lycopersicum
Also known asPlum tomato · Italian tomato · Egg tomato
Environment
The bounded range this crop tolerates. Strict on light; outside the DLI band, yields drop sharply.
Climate and zones
- USDA zones
- 10–13 (winter low around -1°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- warm (summer, frost-sensitive)
Growing systems
Root mass: very heavy. Thin-channel systems can't hold this crop.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Perlite (Expanded volcanic glass) | neutral / inert | very low | low |
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 1 |
| vegetative | 3 | 1 | 2 | 2.2 |
| flowering | 2 | 2 | 3 | 2.6 |
| fruiting | 1 | 2 | 4 | 3 |
Companion-growing notes
- Heavy uptake of potassium, calcium, phosphorus. Co-grown crops with the same demand will end up deficient even at "correct" EC.
- Releases root compounds that can inhibit other crops in a shared reservoir.
- Very high transpiration. Reservoir drops fast; expect daily top-ups and EC creep.
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
A productive hydroponic tomato for sauce-making. Dutch bucket, drip or large DWC systems. EC 2.0-3.5 mS/cm. pH 5.5-6.5. Temperature: 20–28°C daytime, 15–18°C night. High light (DLI 22-30 mol/m2/day). Determinate varieties (most Romas) grow as compact bushes (60–90 cm) and need only staking or caging rather than the elaborate string training of indeterminate types. From transplant to first harvest: 75-95 days. The concentrated fruit set gives a flush of 20-40 tomatoes over 3-4 weeks, ideal for batch sauce-making. For fresh pasta sauce, halve the tomatoes, roast at 200°C until concentrated and slightly charred, then blend or pass through a food mill; for canning, blanch, peel, core and process in a water bath or pressure canner. San Marzano varieties are the standard for Neapolitan pizza sauce. Blossom end rot is the main quality issue, controlled by consistent calcium and watering.
Notable varieties
| Cultivar | Type | Days | Size | Notes |
|---|---|---|---|---|
| San Marzano | heirloom | 80 | 110 g | Italian DOP heirloom from volcanic soil near Vesuvius. Indeterminate vines, elongated thin-skinned fruit with low water content and dense flesh. The canonical pizza-sauce tomato. Needs staking and benefits from drier conditions; foliar disease prone in humid climates. |
| Roma VF | open pollinated | 75 | 80 g | The supermarket plum tomato. Determinate, sets all its fruit in a 3-4 week window. VF = resistance to Verticillium and Fusarium wilt. Reliable producer, average flavor, ships well. |
| Amish Paste | heirloom | 85 | 230 g | Pennsylvania Amish heirloom. Indeterminate, larger than most paste tomatoes (often 220-280g). Less acidic than San Marzano, makes thicker sauce with less reduction. Slower to ripen. |
| Opalka | heirloom | 85 | 200 g | Polish heirloom. Elongated horn-shaped fruit up to 15cm. Thin walls, almost seedless, very dense flesh. Indeterminate. Excellent for sauce and drying; thin skin makes fresh use less practical. |