BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Phleum pratense | Timothy 



GENERAL BOTANICAL CHARACTERISTICS : 
Timothy is an introduced, cool-season, perennial bunchgrass that grows
from 20 to 40 inches (51-102 cm) tall [114,129].  Culms emerge from a
swollen or bulblike base and form large clumps.  The flowering heads of
timothy are cylindrical and spikelike, and about 6 inches (15 cm) long.
The one-flowered spikelet produces seeds that are small and enclosed in
awned, urn-shaped husks [23,90,139].  Leaves of timothy are flat and 3
to 13 inches (7.6-33 cm) long [119].  Timothy is generally short-lived
(4 to 5 years) but can live up to 6 or 7 years [124].  Timothy has a
moderately shallow and fibrous root system; roots can extend to 48
inches (120 cm) in depth [129,139]. Timothy is nonrhizomatous [114,119].
Timothy plants contain corms at their base which are annual, forming in
early summer and dying the next year when the seed matures [47].

Timothy forms vesicular-arbuscular endomycorrhizal associations [143].  


RAUNKIAER LIFE FORM : 
   Hemicryptophyte
   Geophyte


REGENERATION PROCESSES : 
Sexual reproduction:  Timothy reproduces mainly from seed.  It is a
prolific seeder [140]; the small, hard seeds are dispersed by livestock,
wind, and other agents [119].  There are 1.1 to 1.3 million seeds per
pound (0.495-.0585 million per kg) [133].  Maximum germination usually
occurs about 3 or 4 weeks after it is harvested, when nearly 100 percent
should germinate.  Germination rates remain high for 1 to 2 years.
Timothy seed remains viable for 4 to 5 years if kept in a dry, cool
place [133].  Timothy seedlings are vigorous and fast growing [18].

Vegetative reproduction:  Timothy reproduces vegetatively through
tillering [2].  When timothy plants are plowed under, many become
reestablished through rooting stems which develop and grow upwards to
the surface.  Vegetative reproduction occurs through buds in the axils
of the leaves, at nodes which may or may not be adjacent to the corms
[29].  Tillering suppression has been noted at the onset of sexual
reproductive growth [2]. 

The major site of carbohydrate storage is in the lower regions of the
stems (corms, stem bases, and stolons).  Adequate carbohydrate reserves
are important in perennial plants for winter survival, early spring
growth initiation, and regrowth initiation after herbage removal [134].
High night temperatures decrease the carbohydrate reserves of timothy.  


SITE CHARACTERISTICS : 
Timothy is adapted to a wide range of climatic and edaphic conditions
but grows best on well-drained moist clay or loam soils [104,140].
Timothy is best adapted to growth in poorly drained alluvial, Humic
Gley, and Brown Podzolic soils [39].  It thrives in deep, fertile,
loamy, silty, and clayey soils of humid regions but can also grow in
thin, gravelly, and rocky substrates if adequately moist [129].

Timothy has escaped cultivation and has become established at medium to
high elevations in the mountains where it grows in moist grasslands, in
aspen and conifer stands, and along roadways.  It has become naturalized
on sites ranging from warm, dry grasslands to cool, moist supalpine
forests [32].  Timothy has a medium to high water requirement and is
intolerant of drought.  It does best on sites where the water table is
low enough to allow at least the upper 6 inches (15 cm) of soil to
remain unsaturated most of the year [108,140].  Timothy is intolerant of
alkaline or acidic soils.  Lower pH limit is 4.5 to 5.0 [124].  It can
tolerate up to several weeks of flooding in the winter but only a few
days during the growing season [39,129].

Timothy needs about 20 inches (50 cm) of precipitation per year on good
soils, and up to 30 inches (76 cm) on less favorable soils.  Irrigation
greatly enhances productivity in dry climates [23,129].  Timothy has
excellent cold tolerance and winter hardiness [129].  It will tolerate
high shade but thrives in partial shade [108].

Timothy does best at medium elevations but grows up to 11,500 feet
(3,506 m) in Colorado [119].  Regional elevation distributions are as
follows [17,18,25,27,50,102,143]:

                               feet              meters
     
     Utah                   500 - 10,000       150 - 3,048      
     Colorado             4,500 - 11,500       1,370 - 3,506  
     Nevada                  up to 6,000       1,830       
     California              up to 6,000       1,830       
     Idaho                   up to 8,400       2,560        
     Montana               3,100 - 8,000       945 - 2,440   
     Alaska                1,300 - 3,015       396 - 919     
     Washington              up to 5,000       1,524       
     Wyoming               5,600 - 9,100       1,700 - 2,775  
     Alberta                 up to 3,200       975          
     British Columbia        up to 4,400       1,340        

Graminoid species commonly associated with timothy are:  sloughgrass
(Beckmannia syzigachne), creeping wildrye (Elymus triticoides), meadow
barley (Hordeum brachyantherum), Nevada bluegrass (Poa nevadensis),
carpet bentgrass (Agrostis stolonifera), big bluestem (Andropogon
gerardi), porcupine grass (Stipa spartea), little bluestem
(Schizachyrium scoparium), Junegrass (Koeleria cristata), prairie
dropseed (Sporobolus heterolepis), Canada wildrye (E. canadensis),
bluebunch wheatgrass (Pseudoroegneria spicata), Idaho fescue (Festuca
idahoensis), reedgrass (Calamagrostis spp.), streambank wheatgrass
(Elymus lanceolatus), red fescue (F. rubra), crested wheatgrass (A.
cristatum), fescue (Festuca spp.), wheatgrass (Agropyron spp.), tufted
hairgrass (Deschampsia caespitosa), and oniongrass (Melica spp.)
[19,74,98].

The following species are often seeded in mixtures with timothy:
bromegrass (Smooth brome), orchardgrass (Dactylis glomerata), Kentucky
bluegrass, fescue (Festuca spp.), wheatgrass (Agropyron spp.), creeping
bentgrass (Agrostis palustris), Canadian bluegrass (Poa compressa), tall
oatgrass (Arrhenatherum elatius), reed canarygrass (Phalaris
arundinacea), creeping meadow foxtail (Alopecurus arundinaceus),
sweetclover (Melilotus), alsike clover (Trifolium hybridum), big
trefoil, birdsfoot trefoil (L. corniculatus), alfalfa (Medicago sativa),
meadow foxtail, and yellow foxtail (Setaria geniculata)
[21,29,39,47,102].

Common overstory species associated with timothy not listed in
Distribution and Occurrence are:  sandbar willow (Salix exigua),
thinleaf alder (Alnus incana ssp. tenuifolia), and western river alder
(A. incana) [14,46,70].  

Species commonly associated with timothy not already listed include:
chokecherry (Prunus), snowberry (Symphoricarpos), woods rose (Rosa
woodsii), sedges (Carex spp.), spike-rush (Eleocharis), rushes (Juncus
spp.), cicer milkvetch (Astragalus cicer), rambler alfalfa (Medicago
media), sainfoin (Onobrychis viciifolia), common yarrow (Achillea
millefolium), field horsetail (Equisetum arvense), yellow salsify
(Tragopogon dubius), aster (Aster spp.), borage (Borago officianalis),
cinquefoil (Potentilla spp.), dandelion (Taraxacum officinale),
willowweed (Epilobium spp.), and dock (Rumex spp.) [10,19,74,84].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Timothy usually occurs in early to mid seral stages, although it can
also dominate in self-perpetuating grasslands.  It is an intermediate
competitor.  It colonizes disturbed areas via seed [123].  Timothy has
been observed in early seral mixed forests [41].  In southwest Ohio, it
was found in fields up to 50 years of age but not in fields 90 years of
age [123].  Timothy does better following disturbance of sites in early
successional stages compared with those in later successional stages.
For example timothy cover was high after disturbance in old fields and
low after disturbance in forests.  Mid-seral old fields contained an
abundance of timothy [123].  In Wyoming, a cottonwood-grass sere is one
of the dominant riparian communities in the Northern Great Plains.  It
progresses from seedlings of Great Plains cottonwood establishing on
newly deposited alluvium, to a thicket of sandbar willow and cottonwood,
to cottonwood forest, to shrubland dominated by snowberry and wood's
rose, to a self-perpetuating grassland dominated by timothy [10].


SEASONAL DEVELOPMENT : 
Timothy begins growth in early spring.  Flowering occurs from June to
September, depending on altitude and latitude [129,143].  Seeds are
formed by midsummer and are released in August.  Timothy produces a
moderate amount of cool-season regrowth in early summer and fall with
adequate moisture and fertility [129].

Some reported dates for anthesis are as follows [133,143]:  

        Colorado             June-September
        Wyoming              June-September
        Montana              June-August
        North Dakota         June-July
        Ohio                 June-July

Timothy seeds are harvested in Missouri in July, and in Minnesota in
early August [133].  There is a critical period in early fall for
transfer of food reserves to the corms [29].

Related categories for Species: Phleum pratense | Timothy