Concept

The ideas and principles behind good horticulture and landscape management.

The Maritime Edge: Observing Coastal Ecosystems from Northern California to Willapa Bay
Concept

The Maritime Edge: Observing Coastal Ecosystems from Northern California to Willapa Bay

A coastal drive from the redwoods to Willapa Bay reveals how wind, salt, and fog shape plant communities, and why the invasive species you see on the Oregon coast are already in your Puget Sound neighborhood.

Read more →
Reading the Landscape: What a Desert-to-Rainforest Drive Teaches About Climate and Plants
Concept

Reading the Landscape: What a Desert-to-Rainforest Drive Teaches About Climate and Plants

A 1,200-mile drive from the Bonneville Salt Flats to the redwood coast reveals how climate shapes plant communities, and how to read the same patterns in your Puget Sound garden.

Read more →
Growing Degree Days: Reading Plant Development
Concept

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.

Read more →
What sp. and spp. Mean (and Why It Matters on a Plant Tag)
Concept

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.

Read more →
Botanical Nomenclature: How to Read a Plant Name
Concept

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.

Read more →
Heat and Growth Metrics: Reading the Season Through
Concept

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.

Read more →
Water and Disease Metrics: Moisture, Evaporation, and What
Concept

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.

Read more →
← All guides