Garden Planet Book

Extension Sources

Everything on this site traces back to one of these. They are listed here so you can go to the originals directly, which is usually a better use of your time than reading me summarize them.

Why extension services

Cooperative Extension is the outreach arm of the land-grant university system. Extension publications are written by people running the trials, reviewed institutionally, and corrected when they turn out to be wrong. Very little other gardening content meets any of those three conditions.

The catch is that extension material is regional by design. Advice from Minnesota about overwintering strawberries will not transfer cleanly to South Carolina, and the sources below are worth reading with that in mind. Where this site cites a regional source for a general principle, it says so.

Find your own

Every US state has an extension service, and most answer questions from home gardeners at no charge. Yours will know your soil, your frost dates, and your local pest pressure better than any national site. Search for your state's name plus "cooperative extension", or find your county office through your land-grant university.

This is the single most underused resource in home gardening. A county extension agent will identify a disease from a photo and tell you whether it is worth treating, which is a better outcome than anything a search engine will give you.

Sources cited on this site

Fruit and berries

Soil and nutrients

Pests and disease

Seed starting and season

Regulatory