Cover crops: buckwheat
Information on the benefits and growth habits of buckwheat planted as a cover crop.
Description
Family
- Polygonaceae (smartweed)
- broadleaf
- summer annual
Cover Crop Use
- after early harvested crops
- as a weed suppressant/smother crop
- as a pollen source
Growth Habits
Germination
- germinates at a soil temperature of 7.0° C or higher
- emergence usually 3 to 5 days after planting
Top Growth
- fastest growing cover crop
- flowers in 4 to 6 weeks and sets seed in 10 to 12 weeks
- there can be mature seeds on plants that are still flowering
- single-stem with height of 30 to 150 cm, usually 45 to 75 cm in 6 weeks
Root System
- fibrous root system, moderately aggressive
- concentrated in top 25 cm
- root biomass is much less than cereals
Overwintering
- very cold sensitive
- easily killed by frost
Site suitability
- wide range of soil types
- prefers well-drained soils with a pH range of 5.0 to 7.0
- performs well on infertile soils
- intolerant of droughty, saturated or compacted soils
Control Options
- do not let buckwheat go to seed - there's a fine line between attaining maximum biomass and allowing the crop to go to seed
- for best results - kill buckwheat within 7 to 10 days of flowering - before the seed matures
- volunteer buckwheat can be controlled by several broadleaf herbicides containing triazine, sulfonylurea and trifluralin.
Sensitivity to Herbicides
- seedlings have been damaged from residues from herbicides containing triazine, sulfonylurea, and trifluralin
Weed Control
- A good stand of buckwheat can usually compete well with most weed species
- Volunteer buckwheat can be controlled by several broadleaf herbicides, depending on the crop being grown
- There are no herbicides registered to control broadleaf weeds in buckwheat but some can be used to control some grass weeds in this crop
Benefits and Cautions
Nutrient Management
- effective at extracting phosphorus from the soil - used by organic farmers for this purpose
Pest Management
- smothers annuals, suppresses and shades perennial weeds
- attracts beneficial insects
- honeybees are attracted
- attract Lygus bugs and tarnished plant bugs
- should not be used in a field with history of root lesion nematode
- prone to white mold and Rhizoctonia
Organic Matter
- not a big biomass producer, especially if planted late summer
- easily decomposable residue
Erosion Control
- rapid growth and umbrella like leaf structure, means fast ground cover
Getting Started
Establishment
- plant buckwheat in the spring after all risk of frost is past or late summer at least 4 weeks before the usual frost date
- seeding rate of 50 to 60 kg/ha - use higher rates if broadcasting
- drilling is a better option - results in even placement and solid stands
- can be killed by early frost
Seed Cost & Availability
- moderate planting expense
- if not available locally, usually can be ordered in
Cover Crop Management
- monitor buckwheat carefully to prevent seedset
Updated: September 19, 2022
Published: September 19, 2022