This study determined nutrient removal rates for 11 common herbaceous perennial crops grown in Michigan. Plant samples were analyzed to determine the pounds of nitrogen, phosphorus, and potassium removed per acre and per ton of each crop. The phosphorus removal rate ranged from 7.1 to 21.5 pounds per ton across all crops. For creeping phlox, removing both roots and tops increased the phosphorus removal rate from 10.5 to 23.4 pounds per ton. The results provide growers with data to help make informed decisions about fertilizer application and comply with regulations on excess phosphorus levels in fields.

1. Determining Nutrient Removal Rates for Selected Herbaceous Perennial Crops
Thomas A. Dudek, Senior District Extension Horticulture Educator and M. Charles Gould, Extension Bioenergy/Biomaterials Educator
Michigan State University Extension-Ottawa County, 12220 Fillmore Street, Suite 122, West Olive, MI 49460
ABSTRACT RESULTS CONCLUSIONS
Perennial crops remove significant amounts of nitrogen, P2O5 and K2O. The
Michigan field-grown herbaceous perennial plant growers lack science-based Table 1. Estimated plants and yield per acre for selected herbaceous perennial varieties for phosphorus removal rate for all varieties ranged from 7.1 to 21.5 lb/ton or 14.2 to
information to help them make informed phosphorus (P2O5) application decisions. the 2009 growing season. 191.4 lb/acre (root mass only). When vegetative tops were removed along with the
Phosphorus removal rates for major herbaceous perennial crops (Coreopsis, Daylily, root mass for Creeping Phlox ‘Redwings’, phosphorus removal rates increased from
Hosta, Iris, Penstemon, Creeping phlox and Wormwood) grown in Michigan were not Plants Yield 10.5 lb/ton to 23.4 lb/ton. Nutrient removal implications for growers are as follows:
known. The purpose of this study was to determine the phosphorus removal rate for Scientific and cultivar name Common name per acre1 (tons/acre)2 • When the whole plant is removed from the field and not just the roots, more P2O5 is
eleven common herbaceous perennial varieties grown in fields in West Michigan. removed from the field.
Plant samples were harvested from commercial nursery fields near Hamilton, • Fields with high soil phosphorus levels will come down over time, bringing the
Michigan and sent to MSU for whole plant nutrient analysis. From the analysis,
Artemisia schmidtiana ‘Silver Mound’ Wormwood 30,000 2
grower in line with Michigan Right-To-Farm guidelines.
calculations were made to determine nutrient removal rates based on harvest yields Coreopsis verticillata ‘Moonbeam’ Threadleaf Coreopsis 30,000 2 • Profit margins are increased when no fertilizer is applied on fields with soil
and nutrient content of each variety. This study found that field-grown herbaceous phosphorus levels greater than 300 ppm. Fields between 150 and 300 ppm receive
perennial crops remove significant amounts of P2O5, as well as nitrogen and Hemerocallis spp. ‘Frans Halls’ Daylily 20,000 10
only enough P2O5 to equal the P2O5 removed when the crop is harvested.
potassium (K2O). The phosphorus removal rate for all varieties ranged from 7.1 to Hemerocallis spp. ‘In the Stillness’ Daylily 20,000 10 • Reduced potential for surface and groundwater contamination due to accounting
21.5 lb./ton or 14.2 to 191.4 lb./acre (root mass only). When vegetative tops were for all sources of phosphorus.
removed along with the root mass for Phlox subulata ‘Redwings’, phosphorus removal Hemerocallis spp. ‘James Marsh’ Daylily 20,000 10
rates increased from 10.5 lb./ton to 23.4 lb./ton. Data generated from this study will be Hosta plantaginea ‘Honeybells’ Hosta 20,000 10
used by growers to comply with Michigan’s Right to Farm guidelines with respect to
phosphorus applications to their farms. Hosta plantaginea ‘Wide Brim’ Hosta 20,000 10
Hosta undulata ‘Undulata Mediopicta’ Hosta 20,000 10
Iris sibirica ‘Caesar’s Brother’ Siberian Iris 30,000 5
Penstemon barbatus ‘Mystica’ Penstemon 30,000 2
Phlox subulata ‘Redwings’ Creeping Phlox 30,000 5
1. Estimated by Walters Garden, Inc., Hamilton, MI 49419
MATERIALS AND METHODS 2. Average annual yield per acre.
Table 2. Nutrients removed on a lb/acre and lb/ton basis for select herbaceous
Herbaceous perennial plant harvest perennial varieties grown in West Michigan.
Eleven of the most common herbaceous perennial varieties grown in West Michigan Figure 1. Hosta roots.
were chosen for whole plant tissue analysis. Perennial plants were selected from
Walters Gardens, Inc. fields near Hamilton, Michigan. All sampled fields were
lb/acre lb/ton
Chelsea loamy fine sand with a 0-6 percent slope. Five plants were randomly Scientific and cultivar name
removed from three randomly selected three-row beds per field. A total of fifteen Nitrogen P2O5 K2O Nitrogen P2O5 K2O
plants per cultivar were harvested for analysis. Whole plants with as much of the root
mass as possible were dug out of each row. The tops of all plants except Phlox Artemesia schmidtiana ‘Silver Figure 2. Harvesting daylilies for
subulata ‘Redwings’ were removed to mimic normal harvest practices. Plant roots 72.1 31.0 96.1 36.0 15.5 48.1
Mound’ analysis.
were vigorously shook to remove as much of the soil as possible, placed in a brown
paper grocery bag and labeled. Coreopsis verticillata ‘Moonbeam’ 39.5 42.9 104.4 19.8 21.5 52.2
Hemerocallis spp. ‘Frans Halls’ 168.5 101.1 257.3 16.8 10.1 25.7
Method of determining P2O5 removal rate
Phosphorus removal rate is determined through plant tissue analysis. The roots of all Hemerocallis spp. ‘In the Stillness’ 265.4 92.2 310.5 26.5 9.2 31.1
plants were analyzed for total nutrient content. Additionally, the tops of Phlox subulata Hemerocallis spp. ‘James Marsh’ 335.9 139.8 380.8 33.5 14.0 38.1
‘Redwing’ were analyzed. This was done because normal harvesting practices for
Phlox subulata ‘Redwing’ is to remove the entire plant. Hosta plantaginea ‘Honeybells’ 204.6 186.8 289.0 20.5 18.7 28.9
Hosta plantaginea ‘Wide Brim’ 336.3 191.4 269.0 33.6 19.1 26.9
Whole plant tissue analysis preparation was done by the Michigan State University
Soil Testing Lab, East Lansing, Michigan. Plants were dried to less than 5 percent Hosta undulata ‘Undulata
188.1 103.3 153.0 18.8 10.3 15.3
moisture and then ground and analyzed for nutrient content. Mediopicta’
Iris sibirica ‘Caesar’s Brother’ 65.2 43.8 80.9 13.0 8.8 16.2
Statistical analysis
Three composite samples, comprising of five plants per sample, were analyzed for Penstemon barbatus ‘Mystica’ 20.8 14.2 44.6 10.4 7.1 22.3
each plant variety. Elemental N, P, K, Ca, Mg, Na, S, Fe, Zn, Mn, Cu, B and Al were
reported in the analysis for each sample. The raw nutrient data from the analysis was Phlox subulata ‘Redwings’1 159.6 64.3 237.0 31.9 12.9 47.4
Figure 3. Daylily roots. Figure 4. Field of Creeping Phlox.
converted to pounds of nutrients per acre and per ton, and then the mean for each
Phlox subulata ‘Redwings’2 89.6 52.5 205.0 17.9 10.5 41.2
variety was determined using Excel software. Only nitrogen, P2O5 and K2O are
reported in this poster. 1. Tops only
2. Roots only REFERENCES
Michigan Department of Agriculture. 2010. Generally Accepted Agricultural and Management
Practices for Manure Management and Utilization. Michigan Commission of Agriculture,
Lansing, MI. pp.29. Found at:
http://michigan.gov/documents/MDA_Manure_GAAMP_129695_7.pdf
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