Landscape and Garden Plant Evaluation - 1999

Bulletin 874-00

Herbaceous Ornamental Evaluations 1999

Pam Bennett
Extension Agent, Horticulture

Carolyn Allen
Master Gardener
Project Co-leader

Barb Brown
Master Gardener
Project Co-leader

Introduction

Clark County Extension Master Gardener volunteers have been evaluating annual plant varieties since 1995. This is the second year for the results to be reported in this format. The field trial plots are located at the Gateway Learning Gardens at the Clark County Extension Office in Springfield, Ohio. They are planted and maintained by volunteers. The plots are typical of the west-central Ohio area; the soil is predominantly clay with a pH of 7.3. The current plots were established in the fall of 1996. The beds were tilled to a depth of 14", then 2" of compost was added. Compost is added each spring and the plots are tilled prior to planting. There is approximately 5000 square feet of bed space in full sun and approximately 1000 square feet in shade.

The selection of plants to be trialed in the garden vary from year to year. The selection is based on performance in prior years, on current trends, and on industry recommendations. In this section, the results of performance for the plants is based on the data collected at the plots. The data reflect the growing conditions of 1999. The purpose of the evaluation is to provide growers, landscapers and homeowners a guide for plant selection for the central Ohio area.

Method

The plants were started in flats by local greenhouses according to the recommended starting dates. They were planted in the plots on May 20, 1999. Rows were spaced 2' apart with 6 plants per row. Vining plants were spaced 4' apart with 4' between rows. Osmocote (14-14-14) was incorporated prior to planting at the labeled rate. A pre-emergent herbicide (treflan) was incorporated between the rows, 6 weeks after planting.

Irrigation was applied during dry periods so that plants received 1" of water per week. See the weather information below for details. No additional applications of fertilizers were made. The plants were not deadheaded1 or pruned during the growing season. There were no applications of insecticides or fungicides. Volunteers weeded the plots as needed; no mulch was used. Plants were grown in full sun, unless otherwise indicated. The material for the shade house provided a 75% shade.

Three people conducted visual evaluations every three weeks, beginning June 10th and ending September 12th. Their evaluations were averaged for the final ratings. The visual rating consisted of flower (color and amount) and foliage evaluation. A rating of 5 was considered to be excellent and a rating of 1 was considered to be poor. The overall flower rating was obtained by averaging the data for flower color and flower amount. The overall rating was obtained by averaging the flower and foliage overall numbers. The season average indicates an average of the monthly totals.

The plants used primarily for their foliage effects do not have a flower rating (NA). Those plants are alternanthera vine, Helichrysum, sweet potato vine, coleus, and Swiss chard. Note: Coleus flowers were not evaluated in this trial, however, some of the plants had flowers that added to the overall attractiveness of the plant.

Each plant is listed by common and botanical name and the seed or cutting source. The overall ratings of excellent, good, average, fair, and poor are based on the final overall season average. Excellent is given to an overall rating of 4 or better, good is 3 to 3.9, average is 2 to 2.9, fair is 1 to 1.9, and poor is under 1.

Plant height and flower size were measured at field maturity on September 15th. Flowers per plant and flower size were determined by averaging the totals for all six plants of each cultivar. For those plants used for foliage characteristics only, flower size may not be available and will be listed as NA. If plants were dead before the final measurement, NA will also be listed.

Weather Information

The last frost in the spring occurred on April 26th. The average last frost date is May 15th. The first frost of the fall was on September 22nd. This was a very light frost and very few plants were affected. A killing frost occurred on October 21st. The average last frost date is October 15th.

The following indicates weather conditions for this growing season as well as normal average temperatures and precipitation.

Plants were irrigated 2x the first two weeks (during establishment), and then 1X each week the rest of the summer. Irrigation amounts applied were the difference between rainfall and 1" of water.

Springfield is in plant hardiness zone 5b.