Cooperative extension offices

Colorado State University Extension

Fort Collins, Colorado, serving Colorado. Listed as a reference, not an endorsement.

Overview

Colorado State University Extension connects Colorado residents with university education and county based gardening resources. This listing is provided for reference, not as an endorsement, certification, ranking, or guarantee of current availability.

Services and programs

  • Horticulture information
  • County offices
  • Plant and soil resources

What to verify before you go

Contact the organization or review its official source before making a trip, placing an order, joining a garden, or applying for funding. Details that commonly change include:

  • Local county office hours
  • Whether a plant clinic or soil service is available locally

Related directory resources

Browse all extension offices or return to the directory hub.

Sources and last verified

Source: Colorado State University Extension. Last checked 2026-10-04.

Colorado State University Extension connects Colorado residents with university education and county-based gardening resources. Local conditions can vary across Colorado, so the statewide source should be paired with the county office serving the garden.

What this listing covers

The source provides horticulture information, county office connections, and plant and soil resources. It is a reference point for finding Colorado-specific guidance rather than a guarantee of a particular local service.

Before contacting an office

Check the local office page for hours, classes, and plant or soil services. Confirm whether the office accepts walk-ins, appointments, or online questions before visiting.

More tools

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Plan

Moon-phase planting calendar

Plan traditional garden tasks around the lunar phases.

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Plan

Seed starting calculator

Find the right time to start seeds indoors.

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Plan

Harvest date calculator

Estimate a harvest window from planting and maturity dates.

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Plan

Succession planting

Map repeat sowings so the harvest keeps coming.

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Garden guides

Browse all guides

Greenhouse growing

Greenhouse temperature guide for seeds and seedlings

Use crop-specific greenhouse temperatures for seed germination, seedlings, frost protection, and ventilation, with practical day and night ranges.

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Diagram of a raised bed cross section showing timber walls, a layer of existing soil or coarse fill, and the measured depth of new soil being added.

Materials

How much soil does a raised bed need?

How to measure a raised bed and turn the volume into bags or bulk cubic yards, with a worked example for a common 8 by 4 bed.

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October calendar diagram showing planting windows for garlic, spring bulbs, hardy greens, and cover crops closing as the first fall frost approaches.

Seasonal

What can I plant right now in my garden?

In early October, most US gardeners can still plant garlic, spring bulbs, hardy greens, and cover crops. Here is what is still open and what has closed.

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Diagram of a tulip bulb in a soil cross section planted at about three times its own height, pointed end up, with a depth marker of 6 to 8 inches.

Fall planting

When should I plant tulip bulbs?

Plant tulip bulbs in fall, about 6 to 8 weeks before the ground freezes. Here is how the window shifts by region and how deep to plant.

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Plant library

Browse all plants
Illustration of a pepper plant stem with leaves and one hanging bell pepper

Vegetable

Peppers

A guide to starting peppers, choosing a warm site, and keeping plants productive through summer.

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Illustration of a carrot root below the soil line with green fronds above

Vegetable

Carrots

Practical guidance for sowing carrots directly, preparing loose soil, and timing successive crops.

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Illustration of a lettuce head with layered rounded leaves

Vegetable

Lettuce

Cool-season planting and harvest guidance for crisp lettuce in beds and containers.

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Illustration of a cucumber vine with lobed leaves and one long fruit

Vegetable

Cucumbers

Learn when to sow cucumbers, how much room vines need, and how to keep harvests steady.

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Glossary terms

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pests and diseases

Aphid

An aphid is a small sap-feeding insect that can cluster on young growth and spread plant viruses. Many aphids also have natural predators.

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plant biology

Apical dominance

Apical dominance is the tendency of a plant's main growing tip to suppress growth from buds lower on the stem and limit branching.

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pests and diseases

Beneficial insect

A beneficial insect helps a garden by pollinating flowers, eating pests, decomposing material, or supporting another useful ecological process.

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plant labels

Biennial

A biennial is a plant that normally needs two growing seasons to complete its life cycle, usually growing leaves first and flowering in the second season.

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Gardening directories

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Cooperative extension offices

NC State Extension horticulture

NC State Extension horticulture provides research based gardening and grower information connected to local county offices across North Carolina.

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Cooperative extension offices

Clemson Extension horticulture

Clemson Extension horticulture publishes home gardening and commercial horticulture information for South Carolina conditions.

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Nurseries and garden centers

American Native Plants

American Native Plants is a wholesale nursery and supplier listing native trees, shrubs, and perennials for professional buyers.

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Nurseries and garden centers

Prairie Nursery

Prairie Nursery is a mail order supplier focused on native plants and seeds for prairie, meadow, and habitat plantings.

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