Have you heard about the phenological calendar? In this article we explain what it is all about and how you can use it in the garden.
Phenology is a very old science that has been practiced for well over a century. It collects the occurrence of certain natural phenomena every year and thus defines 10 phenological seasons. We will explain to you exactly what phenology is and how you can use the natural seasons in the form of a garden planner to cultivate your garden very close to nature and thus bring in rich harvests.
What is phenology?
Phenology deals with developmental steps or behavior in plants and animals that occur anew every year, but on different dates depending on the weather. Observations such as flowering times or the flight of migratory birds to the south are documented in order to be able to provide useful recommendations for agriculture, climate research and beekeepers.
The word "phenology" means "the study of phenomena". Phenological studies deal with when and why which weather-related events occur over the course of the year. Both the behavior of the animals and the behavior of the plants can be studied. Because both react very sensitively to small changes in temperature or weather and adapt their behavior as best they can to the respective conditions. Examples of phenological observations on plants are the times when the leaves sprout, when they flower, and when the fruit or leaves drop. In the case of animals, for example, points in time such as the beginning of hibernation, the mating season or the laying of young can be recorded. However, most phenological calendars are based on plants because they can be easily located and regularly checked.
Phenological indicator plants and seasons
By documenting developmental stages of certain indicator plants, phenological calendars are created that are used in agriculture, derclimate research, the pollen information service and even by the tourism industry. The so-called "early spring" begins, for example, when the hazelnut (Corylus avellana) blooms. The seasons of the phenological calendar always begin and end with such a natural phenomenon.
Phenological calendars are created annually with the help of indicator plants. Development steps of these phenological indicator plants are called phenophases - they mark the beginning of phenological seasons. The phenological calendar has a total of ten seasons and natural events that characterize each of them. As with the classic seasons, one of them always ends with the beginning of another, i.e. when the next natural event occurs.
The highlight of the phenological seasons: they are not the same everywhere. Have you ever noticed with surprise that the snowdrops in the neighboring village start to bloom much earlier or later than in your place? This is because the phenological seasons are different everywhere - that's quite logical, after all it stays cooler longer in some places, it rains more, freezes more or the sun shines more. The phenological calendar is therefore individual at each location. The following indicator plants and their developmental stages classically define the beginning of the ten phenological seasons:
- Hazelnut blossom (Corylus avellana): early spring
- Forsythia blossom (Forsythia x intermedia): first spring
- Apple Blossom (Malus): Full Spring
- Elderberry (Sambuccus nigra) blossom: early summer
- Blossom of Small-leaved Lime (Tilia cordata): Midsummer
- Ripeness of early/August/Clear apples (Malus x domestica): late summer
- Ripeness of elderberries (Sambuccus nigra): early autumn
- Ripeness of the horse chestnut (Aesculus hippocastanum): full autumn
- Autumn color of English oak (Quercus robur): late autumn
- Leafless Oak (Quercus robur): Winter
If one of the indicator plants mentioned above is missing in an observed area, other plants are used as a substitute. For example, flowering of hazelnut (Corylus avellana) and snowdrop (Galanthus nivalis) occur simultaneously and ripening of early apples ( pen altydomestica) can be replaced by the fruit ripening of mountain ash (Sorbus aucuparia).
Tip: If you look at the phenological seasons in comparison to the calendar seasons of recent years, you can see a shift: the "natural" seasons are no longer accurate as a result of climate change in the periods in which we expect them to appear on the calendar. This is why we often feel that spring arrives "too early" and winter "too late": after all, the classic calendar cannot adapt to the climate.
Gardening according to the phenological calendar
As a gardener, beekeeper or allergy sufferer, you can benefit directly from phenology. You can recognize sensible times for sowing, transplanting and harvesting or also predict the imminent occurrence of pollen or plant pests. The mechanisms of nature are used to cultivate the plants under the best possible conditions.
If you garden according to a phenological garden plan, you use the indicator plants as "measuring instruments", so to speak, which probe their environment with complex biological mechanisms and react sensitively to it. The phenological calendar can be used by gardeners to derive recommendations for irrigation, the occurrence of certain pests and the right times for sowing, planting and harvesting. In addition, the requirements of vegetables, fruit or ornamental plants can be described using the phenological seasons: some can be planted in early spring, while others should not be brought outside before full spring begins.
By the way, many beekeepers help from phenology: You know in which phenological season which forage plant flowers and in which the bees wake up from hibernation and start flying or producing honey.
Tip: Year after year, many people benefit from the documentation of phenological events: The Pollen Information Service receives its information and, above all, forecasts from the German Weather Service (DWD), which in turn provides phenological data for this collects data. In this way, pollen allergy sufferers can be notified in good time and are prepared for annoying hay fever.
Phenological calendar as a garden planner
A phenological calendar as a garden planner will help you align gardening with the phenological seasons. Become at any phenological seasonRecommendations for action given for the garden.
Phenological garden planners are usually books, tables or charts that can be reused annually and link different gardening activities to the phenological seasons. They answer questions like the following: In which of the ten natural seasons can I sow something? In which phenological season do I have to be particularly careful about aphids? And above all: How do I recognize the seasons that I want to use as a guide?
Of course, using a phenological garden plan means that the gardener himself has to be aware of when the season change occurs in his garden. Ideally, there are suitable indicator plants in the vicinity, from which the natural seasons can be read.
Tip: In Germany, the German Weather Service collects phenological data in all regions of Germany with the help of around 1200 volunteers. He is constantly looking for new committed observers who are of course instructed in their work and receive an expense allowance for their service to research.
Advantages of the Phenological Calendar
As you read above, gardening according to the phenological gardening calendar requires a few small observations of nature. But using phenology has a number of advantages for you:
- You don't have to buy a phenological garden calendar every year.
- A phenological garden calendar works the same everywhere and can be used anywhere in Germany.
- Working in the garden is more often rewarded with success: You experience fewer losses due to frost, heat or pests and you get richer harvests.
- By the way, your eye will be sharpened for events in nature and you will experience that the seasons are not "worse" or "not the same as they used to be", but simply change dynamically.
With so many good reasons, some of you may already be wondering: why didn't I start using phenology in the garden long ago? The beginning is not that difficult: A phenological garden planner is needed, look for suitable indicator plants in your area - and off you go!
By the way: Of course there are alsoGarden planners who cling to the months of the year in a very classic (and somewhat inflexible) way. And if you don't want to start phenological gardening right now, take a look at our sowing calendar.