How to take growth measurements–National Ornamental Grass Trials
These are the measurements which are expected for the trial data collection. Please use ‘National Ornamental Grass Evaluation form-August 2013’ to collect data. Final trial measurements should be taken towards the end of growing season, which will typically be in late August/September. Please post on National Grass Trial blog, with photos. https://grasstrials.com/
- The same person(s) should take growth measurements for uniform data collection.
- Please see visual guide sheet for photos of data collection measurement diagrams
- Please take photos of all individual grass cultivars, especially at time of highest ornamental value
1. Date of spring green up or first growth: Dried vegetative growth and inflorescence should be cut back before growth occurs, cut approximately 4-6 inches or 11-16 cm above the crown.
2. Height: an average of the highest point, including inflorescence if present
Measure grass height (leaf or inflorescence) at the tallest vertical point (do not straighten up the plant; i.e., droop height) where the bulk of a plant’s mass occurs.
If the plant has only 1 inflorescence and the bulk of the mass occurs in the leafy portion of the plant, measure the tallest leaf height. (If the inflorescence provides a bulk of the mass, then the tallest portion of the inflorescence is measured)
3. Width: At widest point, does not include lodging. (Lodging=The tendency of grasses to bend over, so that they lie more or less flat on the ground.)
4. Foliage color: Use Royal Horticultural Society’s color chart if available, or use free online chart from the RHS: http://rhscf.orgfree.com/ Describe color (Example: RHS-72A, red-purple) as best you can. Also, indicate approx. percentage of plant which is not ‘normal’ green. Example: ‘’P. virgatum ‘Ruby Ribbons’ is 50% red-purple”
5. Plant form or overall growth habit rating, including uniformity and lodging.
1= 80% or more of the plant is prostrate
2= approximately 66% of the plant is prostrate, or is lodged or is in any way ‘non-uniform’
3=50% lodging or prostrate
4=80% or more of the plant is upright, uniform, very little lodging
5=95% or more of the plant is upright, uniform, attractive, very ornamental, no lodging
6. Flowering date: Initial date when inflorescence appears.
7. Floral impact:
1= no impact (no inflorescence present);
2= 25% impact
3= 50% impact
4=75% impact
5=95% impact, very showy
8. Fall color: note color and date of change.
9. Self-seeding: Observe throughout the year:
1=many seedlings near plant
3= some seedlings
5=no seedlings
10. Winter injury or survival:
1=dead
3=50% injury
5= no winter injury
11. Pests: (Note type of injury, i.e., leaf spot, rust, etc.)
1=pest evident and detracting from appearance
3=some pest damage, to 50% of plant
5= no pest
12. Landscape Impact Rating Scale (from B.Pemberton, Texas A&M)
1 = Very little or no ornamental value in the landscape. Growth weak with poor foliage color, high rate of lodging, little flowering (if flowers should be present) and/or high rate of disease or insect damage.
2 = Below average landscape appearance and value. Vigor poor with significant problems with plant habit and/or disease or insect damage.
3 = Average landscape appearance and value. Vigor good, but with some problems with plant habit, and/or disease or insect damage.
4 = Above average landscape appearance and value with only minor problems with
plant growth habit and disease or insect damage.
5 = Outstanding landscape appearance and value. Good vigor, foliage color, and flowering (if flowers should be present), with little or no disease or insect damage.
13. Comments: Any other noticeable traits not covered above or additional comments about growth characteristics.
National Ornamental Grass Trial-measurement diagrams
National Ornamental Grass Trials Evaluation Form-August 2013
3/13jr/mm; edit 8/13
National Grass Trials 