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The ideas and principles behind good horticulture and landscape management.

Growing Degree Days: Reading Plant Development
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Growing Degree Days: Reading Plant Development

Growing degree days are the accumulated heat units that drive every biological event in your landscape. HortGuide uses base 32°F for maritime climates.

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What sp. and spp. Mean (and Why It Matters on a Plant Tag)
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What sp. and spp. Mean (and Why It Matters on a Plant Tag)

You are reading a pest profile, a nursery tag, or a soil report and you hit it: *Otiorhynchus* sp.Or maybe *Otiorhynchus* spp. One *p* or two.

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Botanical Nomenclature: How to Read a Plant Name
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Botanical Nomenclature: How to Read a Plant Name

I watched a grower in this region lose thousands of lavender starts in a single freeze because of a name.

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Heat and Growth Metrics: Reading the Season Through
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Heat and Growth Metrics: Reading the Season Through

Growing degree days (GDD) measure heat accumulation and predict pest emergence, disease development, and plant phenology. Learn to interpret GDD data for your region.

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Water and Disease Metrics: Moisture, Evaporation, and What
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Water and Disease Metrics: Moisture, Evaporation, and What

Leaf wetness duration and temperature determine infection risk for fungal diseases. Use these metrics to time preventive applications.

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