For Oregon State information check out:

USA National Phenology Network: offers charts, data bases and informative articles.

One exciting aspect of gardening is the amount of knowledge we are assimilating without our knowing we are learning. We accumulate so much knowledge through experimentation and reading. The enthusiasm to try a new plant or idea will keep you an active gardener, mentally and physically.

The beginning of the gardening season is akin to the New Year’s resolutions and goals we set for ourselves in January. Now we have moved into the “Gardeners New Year” setting specific resolutions and goals that will keep us inspired and enthusiastic for months to come.

The stimulus this season could be the study of phenology. The science of phenology is defined as the “science dealing with periodic biological events that are influenced by weather and climate.” More simply put, it can be called nature’s calendar; some refer to it as gardening by the signs.

The term sounds new but it is considered to be one of the oldest environmental sciences. There are Chinese records dating back to 974 B.C. The Japanese have kept track of the blossoming of cherry trees for the past 1,200 years.

The goal of the study is to develop benchmarks of life stages, including sprouting, flowering and loss of cells’ power of plant growth, in relationship to weather conditions and animal or plant responses.

You may think it sounds a little like the folklore you heard in the area you grew up in. Perhaps in some cases there is a correlation between some of the folklore and phenology. In our very well-organized and planned-out lives, we tend to plan on a calendar without regard to what is going on outside. Maybe it is time to change our ways.

I grew up with the Good Friday theory of planting sweet peas or potatoes on that day. Since Good Friday can fall anywhere within a four-week time frame, that practice never made sense to me. We are slowly giving up some of the folklores that don’t make sense and learning to trust soil temperatures, germination charts and now learning more about phenology.

This season you can start recording your observations of weather, plants, pests and diseases to develop your own phenology information. It will require a closer look at what is happening in your landscape and then being diligent about recording your observations.

I consider the relationship between my forsythia bush and my daffodil patch the beginning of my phenology study. For years I have tracked their development.

I watch for my forsythia to start to show flower color, then check my daffodils and observe they are starting to form buds. Last year the forsythia started blooming on March 4; this year it was March 27 when I noticed the first blush of color. This year I will note any insects that appeared in the landscape during that same time slot of budding out through full bloom of both and also pay more attention to other perennials.

The lilac was chosen as the indicator plant when phenological observation networks were established in the U.S. during the 1950s. Cloned lilac plants were used with the theory being that any difference in plant development from different sites would have to be due to environmental effects, not differences between plants since they were genetically identical.

The study resulted in starting to fit the puzzle pieces together. Not only did the study help establish correlation between weather and plant development, it started documenting the relationship between a specific plant and its pest and disease damage.

Insect problems tend to occur during certain life stages of a plant. Insects have life stages that occur to reach maturity. Some of those life stages are detrimental to plants. Phenology can help determine when, if at all, combative measures need to be taken for either pest or disease damage. One thing leads to another and it will encourage you to identify and research the life cycle of insects.

An example is one presented by Windows to the Universe, a website of the National Earth Science Teachers Association. “Fruit trees, like apple, peaches and pears are pollinated by insects, which have a seasonal life cycle — they take time to develop from egg to larva to adult. If the trees flower earlier in the season, they may be out of sync with pollinators. For example, if an insect is still in the egg or larval stage, they will not be able to fly from tree to tree and transport pollen from one plant to another. Without pollination, the flowers are not fertilized and will not produce fruit.”

Considering all our microclimates, putting together your Central Oregon’s phenology puzzle may be harder than the examples listed on websites I looked at. I’m doubting that when lilacs are in full bloom we could plant beans. Our soil may still be too cold for the minimum soil temperature of 60 degrees needed for germination — but then, you never know unless you do some experimenting and recording.

However, I am tempted to try planting peas when daffodils begin to bloom. Also when dandelions bloom, plant spinach, beets and carrots. Guess I should do some soil prep work for a little experimental garden.

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