With a stretch of cold weather coming up and many vegetable crops already planted, here are some resources on protecting your crop.

Rebecca Shortt – OMAFRA

Q. I don’t have complete sprinkler coverage and can’t frost protect (e.g. drip, traveling gun).  Should I irrigate before the frost event?

A. If the soil is dry then, YES, an irrigation today, BEFORE the soil cools, will help (can protect 1 degree C or so).  Do this before evening – you want the plants to be dry tonight.


Should I Irrigate Ahead of the Coming Freeze? – MSU

Irrigation For Frost Protection – OMAFRA

Frost Protection Tools – OMAFRA

Moist, non-cultivated soil retains more heat – MSU

Frost/Freeze protection using irrigation – Irrigation-Mart

Freezing crops and soil – Iowa State Extension

Anne Verhallen – OMAFRA
Comments on irrigation water temperature

  • Where is the irrigation water coming from  – in regards to temperature – is it cooler than the soil currently (years ago researchers at Harrow looked at watering from the well on site – it actively cooled the soil which was a problem early on with tomatoes – and yes I realize they are more cold sensitive)
  • What is the forecast in terms of sun – moist soil will hold heat but it needs sun to build heat (again years ago working with windstrips again in tomatoes, I never worried if we were sunny before a cold night – the worrisome ones were the cool cloudy days followed by the clouds disappearing and a cold clear night)

Effect of Different Soil Surfaces on Temperatures at 4 ft – Original Source

SoilRelative Temperature
Bare, firm, moist soilWarmest
Moist soil, shredded cover crop0.5 F colder
Moist soil, low cover crop1 to 3 F colder
Dry firm soil2 F colder
Freshly disced soil2 F colder
High cover crop2-4 F colder


2 comments on “Frost Protection Resources

  1. Pingback: Frost Protection Resources — ONvegetables | onspecialtycrops

  2. Miguel Bravo

    Hola, muy interesante esta investigación y consejos.
    Me demuestra que en nuestra zona y a pesar de estar tan distante de Uds, el fenómeno frió, suelo seco y helada nocturna, tienen el efecto similar a lo acontecido con su localidad.
    Cada vez que recibo sus informes, los leo atentamente, comparto la información, los guardo y son de mucha utilidad en nuestra actividad agrícola.
    Disculpen haberme extendido, pero es necesario que lo sepan Uds.
    Muchos saludos y cuídense !!!

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