Greenly Garden

Last and first frost dates in Koblenz

Germany

In Koblenz the last spring frost usually comes around 27 April and the first autumn frost around 12 November, which leaves about 199 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 30 May to 23 July.

Last spring frostaround 27 April
First autumn frostaround 12 November
Frost-free days199 days

Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.

When is the last frost in Koblenz?

The last frost in Koblenz usually comes around 27 April: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 6 April, while corn waits until 5 May. The first autumn frost follows around 12 November, about 199 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha4 March – 4 August13 April – 13 September4 May – 13 September
Ageratumfrom 14 March—from 30 May
Arugula——sow 6 April – 8 October
Basil14 April – 10 September22 May – 18 October12 June – 18 October
Beet——sow 6 April – 13 September
Bell Pepper23 March – 24 May22 May – 23 July12 June – 23 July
Black-eyed Susanfrom 10 February—from 4 May
Bok Choy9 March – 21 September13 April – 26 October4 May – 26 October
Borage——sow 4 May – 18 September
Broad bean——sow 6 April – 4 August
Broccoli——sow 6 April – 28 July
Brussels Sprouts30 January – 25 June16 March – 9 August6 April – 9 August
Busy Lizziefrom 9 February—from 4 May
Cabbage——sow 6 April – 5 July
Calendula——sow from 6 April
Carrot——sow 6 April – 20 August
Cauliflower2 February – 28 July16 March – 8 September6 April – 8 September
Celeriac26 January – 25 May13 April – 10 August4 May – 10 August
Celery26 January – 4 June13 April – 20 August4 May – 20 August
Celosiafrom 30 Marchfrom 14 Mayfrom 4 June
Chamomile——sow 6 April – 8 September
Chayote16 January – 18 May14 April – 14 August5 May – 14 August
Chickpea——sow 6 April – 25 July
Chicory19 February – 19 August—6 April – 13 September
Chili Pepper23 March – 30 June22 May – 29 August12 June – 29 August
China asterfrom 31 Marchfrom 22 Mayfrom 12 June
Chives——sow 6 April – 30 August
Cilantro——sow 6 April – 9 September
Corn——sow 5 May – 25 July
Corn poppy——sow from 6 April
Cosmosfrom 30 Marchfrom 14 Mayfrom 4 June
Cucumber24 April – 31 July22 May – 28 August12 June – 28 August
Daikon——sow 6 April – 6 September
Delphiniumfrom 16 January—from 6 April
Dill——sow 6 April – 19 September
Edging lobeliafrom 9 February—from 4 May
Eggplant23 March – 24 May22 May – 23 July12 June – 23 July
Florence fennel27 February – 4 August13 April – 18 September4 May – 18 September
Foxglovefrom 29 December—from 6 April
Garden sorrel——sow 6 April – 7 September
Green Beans——sow 4 June – 2 August
Hollyhock——sow from 6 April
Hyssop——sow 6 April – 31 July
Kale——sow 6 April – 1 September
Kiwano7 April – 7 August9 May – 8 September30 May – 8 September
Kohlrabi——sow 6 April – 11 September
Leek5 January – 16 May16 March – 25 July6 April – 25 July
Lemon balm——sow 6 April – 3 September
Lettuce——sow 6 April – 16 September
Lisianthusfrom 19 Decemberfrom 16 Marchfrom 6 April
Lovage——sow from 6 April
Luffa10 April – 1 June22 May – 13 July12 June – 13 July
Marigoldfrom 2 Marchfrom 13 Aprilfrom 4 May
Marjoram23 March – 19 August—12 June – 18 October
Melon24 April – 18 July22 May – 15 August12 June – 15 August
Microgreens——sow 4 June – 29 October
Moringa9 April – 24 August3 June – 18 October24 June – 18 October
Moss rosefrom 16 February—from 4 May
Mustard greens——sow 6 April – 28 September
Napa cabbage11 March – 29 August13 April – 1 October4 May – 1 October
Nasturtiumfrom 6 Marchfrom 13 Aprilfrom 4 May
Okra10 April – 12 August22 May – 23 September12 June – 23 September
Oregano15 January – 9 August16 March – 8 October6 April – 8 October
Pansyfrom 19 Januaryfrom 16 Marchfrom 6 April
Parsley——sow 6 April – 28 August
Parsnip——sow 6 April – 17 July
Peanut15 April – 8 July22 May – 14 August12 June – 14 August
Peas——sow 6 April – 30 August
Petuniafrom 20 Marchfrom 22 Mayfrom 12 June
Physalis25 March – 5 July9 May – 19 August30 May – 19 August
Pumpkin10 April – 6 June22 May – 18 July12 June – 18 July
Purple coneflowerfrom 13 January—from 6 April
Radish——sow 6 April – 13 October
Sage26 January – 5 August16 March – 23 September6 April – 23 September
Scarlet sagefrom 18 March—from 30 May
Snapdragonfrom 10 Januaryfrom 16 Marchfrom 6 April
Soybean——sow 12 June – 24 August
Spinach——sow 6 April – 18 September
Stevia21 March – 26 June9 May – 14 August30 May – 14 August
Stock——sow from 6 April
Sunflower——sow from 4 June
Sweet alyssum——sow from 6 April
Sweet Corn30 March – 19 August21 April – 10 September12 May – 10 September
Sweet peafrom 2 Februaryfrom 16 Marchfrom 6 April
Sweet William——sow from 6 April
Swiss Chard——sow 6 April – 13 September
Thyme——sow 6 April – 25 July
Tomato18 March – 1 June9 May – 23 July30 May – 23 July
Turnip——sow 6 April – 15 September
Watercress——sow 6 April – 26 September
Watermelon24 April – 6 July22 May – 3 August12 June – 3 August
Zinniafrom 29 Aprilfrom 3 Junefrom 24 June
Zucchini1 May – 5 August22 May – 26 August12 June – 26 August

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

When the soil warms up in Koblenz

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 8 days before the last spring frost and 15 °C 33 days after it.

SoilDateAgainst the last spring frost
5 °C21 February65 days earlier
10 °C19 April8 days earlier
15 °C30 May33 days later
18 °C12 June46 days later

Frost dates near Koblenz

Of the nearest cities on our list, the last spring frost ends earliest in Wiesbaden (5 April) and latest in Frankfurt (13 April).

CityDistanceLast spring frostFirst autumn frost
Bonn54 km8 April19 November
Wiesbaden56 km5 April23 November
Mainz65 km5 April23 November
Cologne79 km6 April20 November
Frankfurt83 km13 April17 November

What to grow at home in winter in Koblenz

Frosts in Koblenz usually come from about 12 November to about 27 April. These plants have indoor care in their Greenly cards and are harvested quickly, so they can be sown on a windowsill in winter.

Weather in Koblenz by month

Average weather in Koblenz over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: June (22.1 °C), July (22.9 °C) and August (23.4 °C). Nights average below 0 °C in January (-0.9 °C) and February (-0.1 °C). About 784 mm of rain falls in a year, on 147 days; January is the wettest month (78 mm) and April the driest (55 mm).

MonthDay, °CNight, °CRain, mmRainy days
January3.9-0.97815
February6.3-0.15912
March9.51.16113
April13.13.35511
May17.37.57612
June22.112.26411
July22.913.27112
August23.413.56011
September19.310.36410
October13.97.26713
November7.92.65914
December50.67013

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

CropWhen to plant
Bearded Irisby 13 October
Crocus13 October – end of December
Daffodil13 October – end of December
Garlic13 October – end of December
Grape hyacinthby 13 October
Helleboreby 13 October
Hyacinth13 October – end of December
Lilyby 13 October
Ornamental onionby 13 October
Peonyby 13 October
Saffronby 13 October
Snowdropby 13 October
Tulip13 October – end of December
Wild garlicby 13 October

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).