Skip to content Skip to navigation
UMass Collegiate M The University of Massachusetts Amherst
  • Visit
  • Apply
  • Give
  • Search UMass.edu
Center for Agriculture, Food, and the Environment

Integrating research and outreach education from UMass Amherst

  • About
    • Overview of CAFE
    • Be Ambitious!
    • History
    • Strategic Directions
    • Research & Outreach Interest Areas
    • UMass Extension Board of Public Overseers (BoPO)
    • Partners
    • Locations
    • Faculty & Staff Directory
    • Contact Information
    • Civil Rights Information
    • Employment Opportunities
  • Extension
    • Extension Outreach Overview
    • UMass Extension In Your Community
    • CAFE Extension Faculty
    • Extension Outreach Projects
    • Extension Initiative Reports
  • Programs
    • Extension Programs Overview
    • 4-H Youth Development
    • Clean Energy Extension
    • Climate Change
    • Cranberry Station
    • Crops, Dairy, Livestock and Equine
    • Food Science Extension
    • Fruit
    • Greenhouse Crops and Floriculture
    • Landscape, Nursery and Urban Forestry
    • Nutrition Education
    • Turf
    • Value-Added Food
    • Vegetable
  • Research
    • Mass Agricultural Experiment Station
    • Information About Accessing Research Funds
    • Research Projects
    • NIFA Integrated Research and Outreach Initiatives
    • Civil Rights Information & Resources
    • Summer Scholars Program
    • REEU Internship Program
  • Resources
    • Resources Overview
    • Interest Areas
    • Extension Sales Portal
    • Agriculture & Commercial Horticulture
    • Community & Economic Vitality
    • Disaster Preparedness
    • Food Safety
    • Home Lawn & Garden
    • Integrated Pest Management (IPM)
    • Land Conservation Tools
    • Pollinators
    • Tick Testing Resources
    • Urban Agriculture
  • Services
    • Services Overview
    • Pesticide Education
    • Plant Diagnostics Laboratory
    • Soil and Plant Nutrient Testing Laboratory
    • Hot Water Seed Treatment
    • Environmental Analysis Laboratory
  • Farms
    • Farms and Facilities Overview
    • Cold Spring Orchard Research and Education Center
    • Cranberry Station
    • Crop and Animal Research and Education Farm
    • Equine and Livestock Research and Education Farm in Hadley
    • Joseph Troll Turf Research Center
  • News & Events
    • Center News
    • Upcoming Events
    • News from the Media
    • Faculty/Staff Brief Bios
    • Spotlight Stories
    • Video Gallery

Clematis

Clematis plants come in endless forms and colors: large, sturdy vines up to 30’ high or smaller vines, 6’ – 8’, suitable for containers; big, bold expansive or delicate bell-shaped flowers. Some varieties bloom in spring, some in summer or fall. For best results, purchase container-grown plants with multiple stems, healthy green growth, and a root system that fills the container.

Clematis Require:

  • 6 hours of full sun each day (generally)
  • cool, moist, shaded roots
  • well-drained, fertile soil
  • support - a trellis, arbor, post or fence
  • regular feeding and watering
  • some pruning at the right time, depending on the type (See chart)

How to Plant

  1. Test the pH level of the soil. Clematis prefer a pH of 6.5 - 7.0.
  2. Provide support for the vine at planting. This helps prevent injury to stems.
  3. Cut stems of the plant back to 12” to minimize breakage during planting and to encourage branching.
  4. Prepare a planting hole 2’ in diameter. Loosen all the soil within a 2’ diameter circle to a depth of 2’.
  5. Estimate the volume of soil in the planting hole. Substitute 1/3 of the volume with compost or well-rotted manure. DO NOT use fresh manure.
  6. Remove enough soil from the center of the hole to accommodate the plant’s root ball PLUS another 3” – 4” in depth.
  7. Set the plant in the hole so that the crown (where stems meet the roots) will be buried 3” – 4” below the surface of the soil.
  8. Fill in around the roots with amended soil. Tamp the soil firmly to eliminate air pockets.
  9. Apply 1 gallon of water when 2/3 of the soil is filled in. Continue to fill in to the soil line, then apply 2 more gallons of water.

Tips for Success

  • Fertilize clematis in April, June and August with a general purpose, balanced fertilizer.
  • Water once a week, deeply, during dry spells.
  • Underplant clematis with low-growing annuals, such as violas, or cover a 4’ – 6’ diameter area with mulch or flat stones to keep roots shaded and cool.
  • Keep mulch 8” away from the base of clematis stems to prevent stem wilt.
  • Protect the plant from mowers and trimmers. Install a barrier, such as hardware cloth, around the base of the plant, 8” away from stems.

Clematis Wilt Management

Prevent breakage and injury to stems. Look for blackened or wilted areas along the stems. Cut any affected stems back to the soil line. Healthy new stems will emerge from the crown. Dispose of diseased stems in a sealed plastic bag.

Clematis Types Bloom Time Flowering Characteristics Best Time to Prune

Group One

Early Flowering

April - May Flowers appear from buds produced the previous season. Examples: C. alpina, ‘Stolwijk Gold’, C. macropetala, C. armandii, C. montana In late June and July, immediately after flowering, prune lightly to control size and to remove broken, weak or dead stems. Prune annually, no later than the end of July.

Group Two

Large-flowered hybrids, often with two flushes of bloom

June - July Flowers appear first from buds produced the previous season and then on new growth. Examples: ‘Nelly Moser’, ‘Henryi” , ‘Niobe’, and many others! In February or March, remove dead and weak stems, then cut back remaining stems to the topmost pair of large, plump green buds – anywhere from a few inches or a few feet from the tip of the stem.

Group Three

Late-flowering

Mid-June through Fall Flowers appear on the last 2’ – 3’ of new growth in early summer to fall. Examples: C. florida ‘Plena’ and ‘Sieboldii’, C. x jackmanii ‘Superba, and‘ Comtesse de Bouchaud’ In early spring, after buds swell, cut each stem to a height of about 2’ - 3’. Leave at least two pairs of buds on each stem.

Resources

http://ag.umass.edu/resources/home-lawn-garden
http://www.mass.gov/agr/massgrown/
www.massflowergrowers.com

Last Updated: April 4, 2012

Home Lawn & Garden Resources

  • Overview
  • Fact Sheets
    • Flower Fact Sheets
    • Fruit Fact Sheets
    • Lawn Fact Sheets
    • Trees & Shrub Fact Sheets
    • Vegetable Fact Sheets
    • Wildlife Management
  • Garden Clippings Newsletters
  • Food Gardening in Massachusetts 2020

Home Lawn & Garden Resources for fact sheets, newsletters, and photos

  • Overview
  • Fact Sheets
    • Flower Fact Sheets
    • Fruit Fact Sheets
    • Lawn Fact Sheets
    • Trees & Shrub Fact Sheets
    • Vegetable Fact Sheets
    • Wildlife Management
  • Garden Clippings Newsletters
  • Food Gardening in Massachusetts 2020

Subscribe to
Home Gardener Email List

Home Lawn & Garden Information »

Center for Agriculture, Food, and the Environment

 

Stockbridge Hall,
80 Campus Center Way
University of Massachusetts Amherst
Amherst, MA 01003-9246
Phone: (413) 545-4800
Fax: (413) 545-6555
ag [at] cns [dot] umass [dot] edu (ag[at]cns[dot]umass[dot]edu)

 

Civil Rights and Non-Discrimination Information

College of Natural Sciences

Login for faculty and staff

CAFE Units

Mass. Agricultural Experiment Station

UMass Extension

UMass Research and Education Center Farms

UMass Cranberry Station

Water Resources Research Center

Interest Areas

Agriculture

Commercial Horticulture

Energy

Environmental Conservation

Food Science

Nutrition

Water

Youth Development & 4-H

Services

Pesticide Education

Plant Diagnostics Laboratory

Soil and Plant Nutrient Testing Laboratory

Hot Water Seed Treatment

Water Testing / Environmental Analysis Laboratory

Projects

Conservation Assessment Prioritization System (CAPS)

Extension Risk Management/Crop Insurance Education

Mass. Envirothon

Mass. Herp Atlas

Mass. Keystone

MassWoods

North American Aquatic Connectivity Collaborative

RiverSmart

UMass Design Center in Springfield

Resources

Extension Sales Portal

Agriculture & Commercial Horticulture Resources

Community & Economic Vitality

Disaster Preparedness

Food Safety

Home Lawn & Garden

Integrated Pest Management (IPM)

Land Conservation Tools

Pollinators

Tick testing

Resources for Faculty and Staff

Extension Programs

4-H Youth Development

Agriculture

Crops, Dairy, Livestock and Equine

Fruit

Greenhouse Crops and Floriculture

Landscape, Nursery and Urban Forestry

Pesticide Education

Turf

Vegetable

Clean Energy

Climate Change

Food Science

Nutrition Education

Value-Added Food

Seal of The University of Massachusetts Amherst - 1863
©2025 University of Massachusetts Amherst · Site Policies · Accessibility