How to Preserve a Garden Harvest

Updated October 2026

Jars of preserved garden harvest, canning and fermenting

Canning, pickling, fermenting, freezing and drying, with the USDA-tested rule that decides which method each crop needs.

Can high-acid foods (fruit, jam, pickles and tomatoes with added lemon juice or citric acid) in a boiling water canner. Can low-acid foods (green beans, corn, potatoes, squash, meat) only in a pressure canner, or freeze, dry or pickle them instead. Always use a tested recipe from USDA, the National Center for Home Food Preservation or your state extension service, adjusted for your elevation. The picker below gives the best options for each crop.

Water bath canning

Jars of high-acid food boiled for a tested time. For fruit, jam, vinegar pickles and tomatoes with added acid only.

Pressure canning

The only tested way to put low-acid vegetables, meat and stock in a jar, using a pressure canner and a USDA time.

Fermenting

Salt and lactic acid bacteria sour the food. Sauerkraut and fermented dill pickles have tested methods.

Freezing and drying

Blanch and freeze, or dry at 140°F. The simplest and most forgiving methods.

Acidity decides the method

Foods at pH 4.6 or lower can be processed in boiling water. Above pH 4.6, Clostridium botulinum spores survive 212°F, so those foods need 240°F in a pressure canner. Tomatoes and figs sit close to the line and always need added acid. Above 1,000 feet, add processing time in a water bath and pressure in a pressure canner.

What to do with your glut

I have a glut of

Method guides

Not recommended by USDA: open-kettle canning, oven canning, canning in electric multicookers, and paraffin seals on jam.

Harvest timing

In most of the country the canning season peaks from July to September, with apples and winter squash in fall. In Florida and along the Gulf Coast, spring and fall crops spread the work out. Pick your region on the what to plant now page for a calendar tuned to your zone.

Sources we checked (October 2026): USDA Complete Guide to Home Canning (2015) and the National Center for Home Food Preservation: Using Pressure Canners, Using Boiling Water Canners, Equipment and Methods Not Recommended, Tomato acidification, Applesauce, Pickled Carrots, Pickled Pearl Onions, Blanching Times; Colorado State University and Montana State University Extension drying guides.

Common questions

Is home canning safe?

Yes, with tested recipes: boiling water for high-acid foods, a pressure canner for low-acid foods, adjusted for elevation.

What foods need a pressure canner?

Low-acid foods: green beans, corn, carrots, beets (unless pickled), potatoes, squash cubes, meat, poultry, fish and stock.

Can I reuse canning lids?

No. Use new flat lids each time. Jars and bands can be reused if they are undamaged.

How long does home-canned food last?

Use it within a year for best quality, stored between 50 and 70°F.