Climate change and risks 5 min

Putting the chill on fruit trees

For plants in temperate climates, it’s a constant balancing act between growing early enough to withstand summer dry spells but not so early that they get damaged by late frosts. With springtime heatwaves now speeding their development, plants have another variable to contend with as well.

Published on 15 April 2021

illustration Putting the chill on fruit trees
© A Faure

A constant balancing act between growing early enough to withstand summer dry spells but not so early that they get damaged by late frosts

In spring, leaves and flowers develop from the material contained inside buds, and budding and flowering mark the start of a new growing season. The tissue in buds has a high moisture content and is extremely susceptible to frost. Following a damaging frost, latent vegetative buds may begin to grow, drawing on the plant’s starch reserves, but if floral buds are frozen, no flower — and thus no fruit — will be produced until the following year. Some tree species and varieties are more frost resistant than others, depending in particular on the speed they develop when temperatures get milder at the end of winter.


Did you experience damage caused by the late frost in April 2022? 

Researchers from CNRS and INRAE need your help to assess the extent of the damage in order to better understand the vulnerability of different species to frost events, which are increasingly common. Share your observations.

For a number of years now, primary plant development stages (bud break, flowering, fruit maturity) have been several weeks ahead of usual times. In order to evaluate the impacts of climate change, INRAE established a network of experimental fruit orchard observatories in France. The INRAE Orchard Observatory (DIVAE) network has six sites throughout the country in a variety of environmental and climatic conditions in Angers, Bellegarde, Clermont-Ferrand, Gotheron, Mauguio and Toulenne. DIVAE research with help to understand and predict the impact of weather on the biology of various fruit trees species (apricot, cherry, peach, apple). Five varieties of each species are being grown, covering a range of early and late development behaviours. In particular, DIVAE will investigate phenology, the study of how periodic events in biological life cycles are influenced by seasonal variation in climate. DIVAE findings on fruit trees are being incorporated into TEMPO, France’s national network of phenology observatories for all living things (plants and animals, both wild and domesticated). 


Peach flowers killed by frost © INRAE, Aline Faure

Studying the effects of a changing climate on commercial fruit-tree species

By selecting contrasting varieties of tree species, DIVAE will be able to study the effects of a changing climate on commercial fruit trees, and woody species more generally, by looking at the role of a plant’s genotype, the environment and the interaction between them. DIVAE was established in 2015, and trees planted then are now coming to maturity. This will allow essential data to be collected on the impact of weather events on plant phenology, such as early bud break, late frost, water stress, fruit development, unseasonable winter temperatures and flowering. Other research activities can also make use of the DIVAE network, so long as the fruit trees’ phenological cycle — the foundation for creating the network — is not disturbed.

Growth stages are assessed and measured in a standardised way across all the sites, including leaf senescence, fruiting, flowering, bud break and overall length of growing period. Certain sites also monitor the end of dormancy to assess chilling requirements. Fruit maturity is assessed using a variety of factors depending on the species, including colour, firmness, and starch and sugar content.

Helping select varieties adapted to future conditions

The DIVAE network will allow researchers to make projections for future orchards in various regions of France and to help select varieties that will be adapted to predicted climate conditions in the near term for the country’s major fruit-growing regions. The major risk factors being studied include earlier flowering in relation to possible frosts, lengthening of the flowering period and failed bud break caused by lack of winter cold, and early fruit fall caused by water stress. Fruit growers are directly affected by these possible changes.

Phenological data will make it possible to explore the physiological traits involved in tree development and behaviour, as well as the hormone signalling of dormancy status in a number of cherry varieties (Vimont et al., 2021) and the role of carbohydrates and water content in predicting frost hardiness in various tree species (Baffoin et al., 2021). The DIVAE network is using an open science approach to make monitoring data available to the scientific and agricultural community via an open-access database. Data from two sites — Angers and Toulenne — are already accessible on


Technical coordination: Aline Faure and David Lanoue
Scientific activities: Guillaume Charrier and Bénédicte Wenden

carte montrant les 5 sites de vergers à INRAE en France

Field observers

  • Angers (UE Horti): David Lanoue
  • Bellegarde (UR GAFL): Alain Blanc
  • Clermont-Ferrand (UMR PIAF): Aline Faure
  • Gotheron  (UE RI): Alexis Rodriguez
  • Mauguio (UE Diascope): Brigitte Montegano
  • Toulenne (UE Arbo): David Allétru




Guillaume Charrier Integrative physics and physiology of trees in a fluctuating environment (INRAE, Univ. Clermont Auvergne)



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