Phenology and Phenomenology

Phenology is about understanding the relationship between natural events. For example, deciduous fruit trees flower after their chill hours are met, once certain daylength and soil temperature conditions occur. Many pollinators start their season after spending a certain amount of time in a semi-dormant state (diapause) followed by several consecutive days and nights of warm temperatures.

Even though these two events have different underlying alarm clocks to initiate them, they typically start at about the same time. That’s why gardeners often connect the flowering of fruit trees with the start of the pollinator season.

Phenological Complexity

The start of pollinator season normally gives way to more bird activity too. Some birds are migratory birds that fly in from out of town as the weather warms. Their arrival time is triggered by conditions at their overwintering grounds that tell them it’s time to move to breeding grounds.

Many local birds stay put through winter surviving on forage, storage, natural adaptation, and cozy places to stay warm. They become more active and mate when they begin to find certain key food sources like their favorite kinds of caterpillars more abundant.

So, again, it’s two different sets of phenological conditions — migratory triggers and local food experience — that initiate increases in bird populations in one location. And, often local bird and migratory bird populations increase simultaneously. But because they both happen in response to different underlying phenological cycles, they may not always coincide.

Good Year/Bad Year

In a good year, fruit trees flower just as pollinating insects awaken to eat their nectar and transfer pollen while they mate and reproduce. As the pollinator larva size up, birds eat some of them and begin to lay and sit nests. Then, their young offspring leave the nest just in time to help control warm season pest populations that might otherwise get out of hand.

In this scenario, gardeners get good fruit set from their well-pollinated trees plus plenty of bird song and natural pest control from thriving bird populations.

Unfortunately, sometimes trees don’t flower due to insufficient chill hours. Or a hard freeze kills the buds. Then early pollinating insects are left hungry so they reproduce less. Birds then have less to eat. So they lay fewer eggs, don’t sit nests, or raise fewer young successfully.

Also, sometimes trees flower before pollinators wake up leaving fewer flowers pollinated. That leads to less insect larva and fewer birds too.

These two completely different, unrelated problems – insufficient chill hours or early flowering/late insect diapause – can lead to similar negative outcomes.

When the phenological events don’t add up to a good year, gardeners can have poor fruit set. Plus, there might be more pest problems as warm season insects break diapause and feast on crops, unchecked by less abundant bird populations.

On the homestead, there’s not much we can do about insufficient chill hours for existing trees. But because organic gardeners have long been aware of this particular set of phenological possibilities, we frequently do the following to mitigate risks.

  • Select and plant fruit trees with varying chill hour requirements.
  • Manually pollinate in unexpectedly cool weather to stave off that poor fruit set problem.
  • Offer an array of plants with different flowering periods to support pollinators, and subsequently birds, to ensure they continue to populate the landscape.
  • Increase pollinator populations by leaving plant debris near our gardens, offering mason bee housing, butterfly shelters, or keeping honey bees that forage year-round on warm days.
  • Feed birds directly to maintain their population, while keeping them from depleting pollinator populations in challenging years.

This is sort of the heart of gardening. We work within the context of the phenological events that occur in our ecosystem. But we intervene to mitigate the impacts of phenological mismatches that might negatively impact our gardening goals.

Weed Phenology

Plants we tend to call weeds are another perfect example of phenological complexity and opportunities for gardener interventions.


Some weeds are auto-germinators that don’t go dormant. They just lie on or under the surface of soil waiting for 10 hours of daylight or a few warm days to trigger them to begin grow.

These weeds are the phenological response to too few plants or insufficient mulch to block light and prevent germination.

Semi-Dormant Seeds

Other weed seeds are semi-dormant. They aren’t really sleeping. They are in a meditative state, tuned into their surroundings, waiting for a few conditions to align and let them know it’s safe to grow. They may need warming soil temperatures to trigger an increase in bacterial activity and nitrogen rich rains to filter into the soil. Or they may need excessively dry conditions and heat to oxidize soil and weather away their outer seed coatings.

When these weeds germinate it’s phenological evidence that the soil is experiencing erratic events rather than the stable conditions most cultivated plants prefer. Depending on what germinates, we can figure out what needs to be done to stabilize soil.

Dormant Seeds

Some weed seeds are genuinely dormant and can remain so for decades. Those truly dormant seeds are in a cryogenic-like sleep, preserved until catastrophic soil events force them out of dormancy.

It could be a change in soil pH caused by a gardener applying lime, sulfur, or hot compost. Gardening practices like using salt-based fertilizers, regular tilling, or excessive over and under watering also cause seeds to break natural dormancy. Acid rain, fire, flood, invasive species altering soil chemistry, and digging pests are some natural causes.

When these weeds happen, gardeners can study the environmental conditions and practices to determine what big phenological changes forced those dormant seeds to germinate. Then, we can decide how to strategically address the cause and control weeds until the soil stabilizes again.

Nature’s Mind

Nature has a reason for causing weeds to germinate at specific times and places just as it does for tying pollinators to different alarm clocks than fruit trees.

We may not always be able to see why, understand the reasoning, or agree with nature’s logic for how this all works. But by becoming more aware of these phenological processes in our environment, we can begin to understand nature’s mind.

Now, I don’t think of nature as a person. I may sometimes say Mother Nature just as a short hand way of referring to the collective intelligence at work all around us. But my view of nature is as a collection of intelligent systems that are complexly interconnected. Also, many of these systems are automated, meaning that they are already set to occur when certain conditions are met.

If I eat food, my body starts digesting and microorganisms get to work converting that food to energy and nutrients. I don’t have to tell them to do this or even be aware that it is happening.

When we feed our soil compost or harvest food, the same thing happens. The processing of whatever we put in or on soil, or the adjustment to whatever we take out, is automated. And we can’t stop that from happening.

To some degree, though, we can influence outcomes. By eating healthier foods, we ensure that the digestion that takes place has more positive impacts on our well-being. To replace what we harvest, we can feed our soil aged, quality compost or light layers of high-carbon, low nitrogen mulches and support beneficial microlife. Whereas by placing fresh manure or just cooled compost on our soil, we may temporarily promote dangerous pathogens or anaerobic and thermophilic bacteria that don’t support plant growth.

These automated systems sometimes seem mysterious because they are far too complex for us to comprehend in their entirety. However, that doesn’t mean we can’t interact successfully with them and even leverage them for our benefit.

Phenological Connections

The way to leverage our limited understanding of phenology is to make connections that are personal to us. For example, when our plum trees flower, I know the peaches will come next followed by pears, quinces, and apples.

Additionally, I know the violets flower with the plums and peaches. So that’s when I start looking for them to harvest their flowers for infusions or plate decorations. The deadnettle and henbit begin to flower with the plums and go through until when the apples flower. I let them flower to feed the pollinators. Then I start collecting the older plants to give to feed to the ducks and chickens before they set too many seeds.

Other connections help me decide when to plant annuals. Like when my biennial fennel starts growing well, I know it’s time to sow lettuce and turnips. When my over-wintered collards begin to flower, peas are safe.

Weather Interruptions

It’s important to note that weather events such as an unexpected hard freeze can interrupt phenological events. Even in nature, as we saw with those earlier examples, phenological mismatches occur and processes fail as a result.

Tying our gardening activities to phenological activities is a starting point, but not a a perfect answer for when to plant or perform specific chores.

We must also check the forecast and grow non-hardy plants indoors to keep safe until after the risk of frost. Row covers, cloches, or cold frames may also be needed to mitigate early cold and still successfully grow marginal crops in a certain area.


Phenology is learned by observing seasonal cycles, taking notes, and reflecting from year to year to make connections.

  • Track dates when leafing or flowering happens.
  • Keep records of harvests and the conditions that led to good or bad years.
  • Identify, study, and record when pests or pollinators start showing up or what conditions are present when they are prolific or controlled.

This kind of attention to detail will develop more thorough phenological knowledge of your landscape. Then, refer back to these records annually to note differences.

Phenology is extremely localized. So, only you can make these connections by studying and attempting to understand how things work in your landscape. But you can figure out what to pay attention to by reading and researching articles about natural cycles and systems in your region.

Experimentation is also necessary to take advantage of the phenological processes at work in our environment. This is where phenomenology comes into play.


Horseradish and mustard are flowering as garlic and chicory are sizing up in early spring. This is also about when mouse-ear chickweed, Persian speedwell, and hairy vetch begin to spread if I don’t control them earlier.

Phenomenology is related to, but not the same as phenology. It’s a kind of parascientific process wherein you learn from and interact with phenomena like (phenological events in your garden) even when you can’t fully understand them.

For example, there is no way I can understand the phenological complexity at work in even a teaspoon of good soil. There is simply too much life, too many connections, and not enough scientific knowledge about the lifecycle and phenological actions of the organisms in soil.

Yet, I can still understand things about soil by taking the scientific knowledge I’ve read about, adding in my observations, and picking up subliminal cues that my cells sense even when my conscious brain misses them. Then, I can use this subjective “knowing” or “intuition” to interact with the phenomena that comprise living soil.

I also think that there’s an element of energetic communication that our rational, western kind of thinking rejects simply because we don’t understand how it works. If you’ve ever been drawn to a person or a place for no apparent reason or known you needed to call someone far away, then you understand this.

In the garden, I swear sometimes plants communicate what they are running out of in the soil even before they show signs of deficiency. Plants also “tell me” where they want to live. It’s as if there’s a hint of heaviness I feel when holding a potted plant near an ideal location.

When we interact with these sensations or phenomena, either by actively following them or intentionally ignoring them to see the outcomes, we learn more about them.

Homesteading with Phenology and Phenomenology

The apple trees are leafing as the hairy vetch and mustard as a cover crop are ready to be cut back. The goji are bushing while as the strawberries are beginning to set noticeable fruit and the oregano is gaining height.

Living in a changing climate, with rapidly evolving diseases and pathogens, a lot of old data like planting calendars or products like herbicides or pesticides simply are no longer reliable. We have to be willing to try new things to get good results in a rapidly altering world.

You don’t need a degree to do this. But you do need enough phenological knowledge to make good guesses at how to engage the phenomena unfolding on your homestead. It also helps to keep up to date with emerging scientific discoveries about soil, climate, and natural systems to help link these two skills more effectively.

As Socrates is famed for expressing, the more you know… the more you know you don’t know. Once you begin to look closely at the underlying phenological connections and complexities in just the natural systems at work on your own homestead, you will be amazed at how completely dependent we are on nature and how little we actually know about how it works.

But don’t worry. You’ll also realize that you don’t have to understand everything to interact with these phenomena effectively. You just need to make an honest effort to engage and interact with these things you don’t entirely understand.

We are natural beings and some of the knowledge for how to engage nature is already built into us. We just need to trust ourselves to try even when our rational minds don’t know why.

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