Illustration: San Marzano tomatoes under the chamber's light

Illustrations: the crop under the chamber’s light, and how it arrives (packaging render).

Packaging render

San Marzano tomatoes 1994

Sarno · Agro Sarnese-Nocerino, Campania · Italy

Volcanic soil and a bone-dry ripening.

Our selection: ranked first of 35 seasons here, 1990–2024, on the recorded weather.

$65per 5 kg box · $85 after harvest

0% reserved · 200 of 200 leftPlants at 70% · closes 7 December 2026

Nothing is owed unless this lot reaches 70% reserved by 7 December 2026. If it doesn't, your reservation is released.

San Marzano tomatoes have been grown on the volcanic plain below Vesuvius for more than a century. In 1994 the season brought about 90 mm of rain from May to August, barely 9 mm in its last five weeks, and thirteen hours of sun a day. It shares the top score of thirty-five seasons on our plum-tomato profile with 1992 and 1997, and was the sunniest of the three.

123
days replayed

1 May – 31 Aug

23.1°
mean temperature

9° to 33°

1615
degree-days of heat

warmth accumulated

92 mm
rain

9 mm in the final weeks

13.1 h
sun a day

estimated from the reanalysis

8.4°
day–night swing

in the final weeks

53
mol/m² of light a day

calculated

What this weather does to the san marzano tomatoes.

Five readings from the recorded season, each against the band the crop does best in (painted green on the dial). The meanings are what growers and agronomists expect of weather like this, not a tasting note.

Heat over the season · in balance

Heat in the range the crop does best in.

Day–night swing while ripening · ideal

Warm days and cool nights deepen colour, sugar and perfume.

Rain in the last 35 days · dry

A dry finish: water is held back and flavour concentrates.

Sunlight · bright

Plenty of light for colour and sweetness.

Days above 35° · none

No heat stress: the plant never shut down to protect itself.

The season, as it happened.

1 May 1994 to 31 August 1994, recorded daily at 40.81°, 14.62° (ERA5 reanalysis via Open-Meteo historical archive). Choose a chapter to mark it on the paper.

Point at the paper to read any day. Arrow keys step a day.

Air temperature, day high to night low · °C6–35
Rain, given as water at the roots · mm0–20
Daily light · mol/m² · calculated0–70
Peak UV · index · calculated0–10
Humidity · %41–92
Soil temperature, top 7 cm · °C14–31
Soil water · m³/m³0.12–0.43
MayJunJulAug

Burgundy ink: the recorded day. Blue: rain. The dashed line is where the chamber is today. Light and UV are calculated from the recorded sunshine.

The ground, and what stands in for it.

In Sarno
Volcanic soil from Vesuvius: loose, dark, and rich in potassium and phosphorus.
In the chamber
Potassium-heavy for fruit set and colour, with phosphorus held up through flowering.
The ledger: every day and the chamber’s settings for it (123 days)
DayDateHigh °CLow °CRH %Rain mmSun hLight hDLIPPFDUVSoil °CSoil water→ Water L/m²→ Mist min
11 May20.013.3770.013.513.850.110107.616.534%3.7—
22 May20.612.2810.410.513.847.29487.417.133%4.2—
33 May18.411.9610.713.813.953.210657.916.133%5.1—
44 May19.28.6710.013.913.958.311668.415.632%4.3—
55 May18.312.5830.89.213.947.79527.516.031%4.2—
66 May16.912.7720.213.014.046.29187.415.831%3.8—
77 May20.012.7620.014.014.053.610638.116.330%4.6—
88 May19.69.5710.014.014.057.311348.416.129%4.4—
99 May17.711.4812.72.714.123.84705.015.230%4.75
1010 May18.512.0780.612.914.139.07686.715.633%3.6—
1111 May19.611.6800.014.014.255.710928.416.131%4—
1212 May19.312.5810.08.814.242.08227.116.730%3.3—
1313 May22.812.6780.013.414.254.810708.318.229%4.4—
1414 May24.316.4720.013.614.357.811268.619.528%4.8—
1515 May24.613.5710.014.014.358.311338.719.427%5—
1616 May25.515.2740.014.014.359.111468.820.326%5—
1717 May25.317.1710.014.014.359.211468.820.825%5.2—
1818 May20.415.47918.54.014.423.84595.118.730%21.137
1919 May19.315.5799.412.914.443.38367.317.640%12.819
2020 May20.514.0790.014.014.451.09828.117.737%3.7—
2121 May21.716.9870.012.614.552.09998.219.535%3.8—
2222 May25.214.4720.014.014.560.211549.019.833%5.1—
2323 May29.016.3590.014.014.560.111499.020.932%6.1—
2424 May26.219.5550.09.514.538.77386.920.930%4.6—
2525 May24.418.9660.014.014.660.011449.021.029%5.1—
2626 May22.915.9840.012.514.655.510578.620.728%4.4—
2727 May23.014.9830.011.514.655.610568.620.127%4.3—
2828 May23.616.0810.013.214.658.911178.920.627%4.7—
2929 May23.814.3760.012.814.760.211399.020.226%4.9—
3030 May26.716.6670.014.014.761.011549.121.225%5.4—
3131 May26.620.2640.014.014.758.110968.922.024%5.4—
321 Jun27.317.3540.014.014.763.712029.422.523%6.5—
332 Jun27.215.0610.014.014.763.311929.421.822%5.8—
343 Jun25.218.2700.013.814.859.511199.021.721%5.2—
354 Jun24.518.4840.013.714.856.510618.822.620%4.6—
365 Jun22.419.4731.513.614.846.18657.821.321%5.73
376 Jun24.216.5570.013.914.857.610818.921.021%5.5—
387 Jun23.716.6450.014.014.863.511899.421.220%6.6—
398 Jun24.713.5630.014.014.859.811189.121.119%5.3—
409 Jun22.615.5780.014.014.954.010108.620.718%4.3—
4110 Jun20.715.9887.611.914.941.67787.319.622%10.515
4211 Jun21.314.7800.813.014.949.09148.119.826%4.7—
4312 Jun19.615.58317.912.014.939.67387.118.633%20.936
4413 Jun20.414.4842.312.414.949.49218.118.836%5.95
4514 Jun20.513.7811.212.814.949.99308.218.934%5.12
4615 Jun22.816.4760.614.014.954.310128.619.832%4.9—
4716 Jun22.716.7840.013.414.954.510158.620.330%4.2—
4817 Jun23.015.9840.013.414.955.410318.720.728%4.3—
4918 Jun24.715.9800.013.414.959.711119.121.527%4.9—
5019 Jun27.317.1690.014.014.961.911529.322.325%5.4—
5120 Jun25.319.0710.113.314.949.89278.222.224%4.7—
5221 Jun25.419.5860.012.214.948.59038.123.323%4.1—
5322 Jun27.418.2700.014.014.957.610718.923.723%5.5—
5423 Jun27.717.4660.014.014.960.911349.223.821%5.8—
5524 Jun28.518.6720.014.014.961.911529.324.320%5.5—
5625 Jun28.820.9730.014.014.961.411439.324.919%5.5—
5726 Jun30.220.9640.014.014.963.511839.525.419%6—
5827 Jun29.920.9610.010.914.950.69438.325.118%5.1—
5928 Jun27.322.7730.014.014.956.710568.824.918%5—
6029 Jun25.519.1834.612.914.948.39008.023.820%8.79
6130 Jun30.619.1710.214.014.959.711149.125.323%6.1—
621 Jul32.722.3610.014.014.959.011019.027.021%6.5—
632 Jul30.822.3720.513.914.957.910828.927.120%6.1—
643 Jul29.921.9780.013.514.955.910468.827.219%5.2—
654 Jul29.722.5840.013.714.855.110318.727.118%5—
665 Jul29.421.3790.013.114.859.411139.127.118%5.4—
676 Jul29.821.3740.014.014.861.811589.326.817%5.8—
687 Jul29.121.7800.014.014.858.010888.926.717%5.2—
698 Jul28.822.0800.012.614.857.310768.927.016%5.3—
709 Jul28.219.9760.313.114.853.910148.526.416%5.4—
7110 Jul28.721.4530.014.014.757.710878.926.416%6.5—
7211 Jul26.520.5510.014.014.754.610298.625.216%6.3—
7312 Jul27.917.8630.014.014.750.19478.125.015%5.3—
7413 Jul28.619.1650.014.014.749.79408.125.415%5.1—
7514 Jul29.520.1670.014.014.755.910588.726.515%5.5—
7615 Jul30.320.4610.014.014.659.611309.026.915%6.2—
7716 Jul30.720.2590.014.014.656.610748.727.315%6.1—
7817 Jul31.421.4580.014.014.658.211078.928.014%6.5—
7918 Jul31.020.7650.014.014.660.111469.028.114%6—
8019 Jul29.622.0720.014.014.559.211318.927.714%5.6—
8120 Jul27.821.7800.013.114.550.59668.126.814%4.6—
8221 Jul28.420.1763.812.114.545.68747.626.116%8.18
8322 Jul27.621.6751.912.914.539.37556.925.220%5.94
8423 Jul30.820.1710.114.014.453.510308.426.320%5.5—
8524 Jul28.021.1783.213.514.446.08877.626.021%7.56
8625 Jul29.720.7730.013.914.450.99838.126.522%4.9—
8726 Jul30.422.3743.111.814.348.49387.826.922%7.86
8827 Jul30.220.5710.113.714.350.79848.026.624%5.1—
8928 Jul30.720.2660.014.014.352.210158.126.722%5.4—
9029 Jul29.722.5661.013.814.344.78727.426.221%5.52
9130 Jul30.619.7670.014.014.255.410828.426.621%5.5—
9231 Jul30.821.3650.014.014.256.010968.427.019%5.6—
931 Aug29.924.1770.113.214.250.79957.927.318%4.8—
942 Aug30.722.3760.813.614.154.010628.227.418%5.9—
953 Aug32.121.7670.013.914.153.510558.128.118%5.5—
964 Aug32.921.4610.013.914.053.910678.228.417%5.9—
975 Aug33.021.8600.013.814.052.510408.028.716%5.7—
986 Aug32.622.0620.013.814.049.89917.728.716%5.4—
997 Aug31.823.6670.013.513.952.610498.028.515%5.3—
1008 Aug31.524.9760.213.413.951.310267.828.615%5.2—
1019 Aug31.123.4770.013.413.952.210477.928.515%5—
10210 Aug32.923.1670.013.413.853.710798.028.815%5.4—
10311 Aug31.423.0710.013.613.853.210737.928.315%5.7—
10412 Aug29.824.2770.013.113.749.49997.628.615%4.9—
10513 Aug30.223.6730.013.013.752.610677.828.214%5.1—
10614 Aug31.321.5750.013.013.753.110807.828.514%5.2—
10715 Aug31.923.0710.013.313.653.210857.829.014%5.3—
10816 Aug32.423.7730.313.113.651.810607.729.314%5.5—
10917 Aug31.222.7730.013.013.552.810847.728.614%5.1—
11018 Aug30.322.5770.412.713.547.99857.227.814%5.3—
11119 Aug30.922.9650.612.713.552.210787.628.415%6.1—
11220 Aug30.023.7690.012.713.452.310847.627.815%5.1—
11321 Aug30.022.7710.012.613.450.310447.327.615%4.9—
11422 Aug31.322.6730.012.513.351.510737.428.215%5.1—
11523 Aug31.223.8700.012.413.349.610377.228.215%4.8—
11624 Aug31.821.2660.012.313.251.710847.427.714%5.6—
11725 Aug28.022.9806.09.413.234.17185.726.617%9.612
11826 Aug27.521.4650.012.113.244.29346.626.121%4.8—
11927 Aug29.220.4540.012.213.150.810787.226.220%5.6—
12028 Aug30.218.9560.012.113.151.110877.226.119%5.7—
12129 Aug29.922.9670.012.113.049.510567.026.718%4.9—
12230 Aug29.623.0730.012.113.047.210116.726.817%4.4—
12331 Aug31.121.4700.012.012.948.910516.827.416%4.7—
Download the chamber recipe (CSV)