Notes on urban and rural gardens

I was introduced to the term garden ecology lab at a presentation given by Gail Langellotto, Oregon State University Master Gardener statewide coordinator.

That is only one of her titles. Her profile includes professor of horticulture, entomologist and principle investigator of the garden ecology lab.

Garden ecology lab is the socio-ecological research in urban and suburban garden systems, according to the posting on their blog site. The group consists of students interested in ecology, horticultural therapy and urban soils.

The plan is to incorporate home gardeners for home garden study sites. At present the garden sites being studied are across the Cascades. The geographical location shouldn’t mean we can’t benefit from the information the study provides. It would be so beneficial if someday the studies extended to Central and Eastern Oregon. That wish would be what my father would call “a pie in the sky” wish.

A blog post on July 29 opened my eyes. The post offered information gathered from 27 vegetable gardens in Corvallis and Portland and tested for “differences between garden sites based upon bed type (e.g. raised beds versus in-ground beds).

All gardens were managed by certified extension master gardeners.

The most frequently given garden advice in articles, books and friend-to-friend is to add organic matter. The advice of adding organic matter is that it improves soil tilth and nutrition.

Research shows this practice developed in large-scale farming operations where farmers struggled to raise their soil organic material content by even 1 percent across tens or hundreds of acres of production.

Nearly every garden in the study sites that was sampled had an excess on the average of 13 percent by volume of organic material.

The soil management guidelines is to aim for a 3 to 6 percent soil. “Raised beds were significantly over-enriched in organic matter (15 percent organic soil on average), compared with in-ground beds (10 percent on average).

To put it another way, master gardener-tended vegetable gardens were over-enriched in organic materials by 2 to 5 times the recommended level.”

One tends to ask, “So, what’s the problem?” The excess in organic matter is likely to contribute to excessive levels of other soil parameters.

All gardens were above the recommended levels for sulfur, phosphorus, calcium and magnesium. Nitrogen, potassium and boron were generally within the recommended levels.

Our garden plots have gotten smaller over the years and it is easy to understand the thoughts and practices of the big family garden no longer apply.

We need to add amendments as needed to correct certain problems but we need to also understand that more is not necessarily better. An example was given that “nitrogen is extremely mobile in soils while phosphorus tends to build up over time.”

The garden ecology lab studies have the potential of helping all of us become more vested and conscientious of how we manage our garden and landscape.

We need to have a starting point and that would be to have a soil test done that would be inclusive enough to offer more than nitrogen, phosphorus and potassium percentages.

Two early posts included Plant of the Week: common yarrow on Aug. 31, 2018, which reinforced to me the value of a plant that is very drought tolerant and a pollinator, plus the foliage is a source of food and habitat of many species of butterfly and moth caterpillars. First Bee List from Native Plant Study was the second posting on Sept. 3 that I have referenced several times. The study is being done in a 3-acre field rather than the home study sites. The post is fascinating as it includes the images of the bees that are listed.

— Reporter: douville@

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