Nursery and Flower Grower

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Figure 1 Examples of growth responses to % air-filled porosity
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Soil Mixes Part 3: How much air and water?

February 20th, 2019
By Steven A Tjosvold
Container soils should have a good balance between air- porosity and water- holding capacity. But what are the favorable levels of these two parameters? Most horticulturists will recommend providing a soil with good drainage.
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Fig 1 soil, water and air
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Soil Mixes Part 2: Water and Air Porosity

February 13th, 2019
By Steven A Tjosvold
Container soils must have the right balance of air-filled and water-filled pore space. This is especially important right after irrigation. I showed in the previous blog that field soils shouldn't be used in containers because they don't drain well and create a saturated root environment.
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Possibly the first indication of downy mildew on impatiens
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More on Downy Mildew Diseases

January 30th, 2019
By Steven A Tjosvold
Now through the spring is the time to take a close look at crops that are susceptible to downy mildew so that the disease can be detected early. This post follows the previous one that describes the general identification and biology of downy mildew diseases.
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Downy mildew on Delosperma caused by Peronospora mesembryanthemi. Plants on right are unaffected.
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Look Out for Downy Mildew Diseases

January 23rd, 2019
By Steven A Tjosvold
Downy mildew diseases have become increasingly important and common on ornamental plants over the last decade in California. The wet and cool weather we recently have had should promote the development of this disease. Now through the spring is the time to take a close look at susceptible crops.
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