Pollen source

The term pollen source is often used in the context of beekeeping and refers to flowering plants as a source of pollen for bees or other insects. Bees collect pollen as a protein source to raise their brood. For the plant, the pollinizer, this can be an important mechanism for sexual reproduction, as the pollinator distributes its pollen. Few flowering plants self pollinate; some can provide their own pollen (self fertile), but require a pollinator to move the pollen; others are dependent on cross pollination from a genetically different source of viable pollen, through the activity of pollinators. One of the possible pollinators to assist in cross-pollination are honeybees. The article below is mainly about the pollen source from a beekeeping perspective.
The pollen source in a given area depends on the type of vegetation present and the length of their bloom period. What type of vegetation will grow in an area depends on soil texture, soil pH, soil drainage, daily maximum and minimum temperatures, precipitation, extreme minimum winter temperature, and growing degree days. The plants listed below are plants that would grow in United States Department of Agriculture. Hardiness zone 5. A good predictor for when a plant will bloom and produce pollen is a calculation of the growing degree days.
The color of pollen below indicates the color as it appears when the pollen arrives at the beehive. Bees mix dry pollen with nectar and/or honey to compact the pollen in the pollen basket. Dry pollen, is a food source for bees, which contains 16 - 30% protein, 1 - 10% fat, 1 - 7% starch, many vitamins, but little sugar. The protein source needed for rearing one worker bee from larval to adult stage requires approximately 120 to 145 mg of pollen. An average bee colony will collect about 20 to 57 kg (44 to 125 pounds) of pollen a year.
==Spring==
===Trees and shrubs - Spring===
Common name 	Latin name 	Blooming months	Pollen color 	Availability 	Source for honeybees
Maple 	Acer spp. 	Feb - Apr 	light yellow 	feral 	fair
Manitoba Maple (Box elder) 	Acer negundo 	Feb - Apr 	light olive 	feral 	good
Norway maple 	Acer platanoides 	Apr - May 	yellow green, olive 	feral 	fair
Red Maple 	Acer rubrum 	Mar - Apr 	grey brown 	feral 	
Grey Alder 	Alnus incana 	Feb - Apr 	brownish yellow 	feral 	
American Chestnut 	Castanea dentata 	May - Jun 	 	mostly ornamental 	
Sweet Chestnut 	Castanea sativa 	May 	 	feral 	good
Common Hackberry 	Celtis occidentalis 	Apr - May 	 	feral 	
Flowering Quince 	Chaenomeles japonica, Chaenomeles lagenaria, Chaenomeles speciosa 'Nivalis', Chaenomeles x superba	Apr - May 	 	feral 	good
American Hazel 	Corylus americana 	Mar - Apr 	light green 	feral and ornamental 	fair/good
Hawthorn 	Crataegus spp. 	Apr - May 	yellow brown 	feral 	fair
White Ash 	Fraxinus americana 	Apr - May 	 	 	
Honey Locust 	Gleditsia triancanthos 	May - Jun 	 	feral 	
American holly 	Ilex opaca 	Apr - Jun 	 	feral 	
Walnut 	Juglans spp. 	Apr - May 	 	cultivated 	fair
Tulip-tree 	Lirodendron tulipifera 	May - Jun 	 	feral and ornamental 	good
Crab Apple 	Malus spp. 	Mar - Jun 	light olive 	ornamental 	
Apple 	Malus domestica, Malus sylvestris 	Apr - May 	yellow white 	cultivated and ornamental 	very good
American Sycamore 	Platanus occidentalis 	Apr - May 	light olive 	feral 	
Plum 	Prunus spp. 	Apr - May 	light grey, grey 	ornamental and cultivated 	
Almond 	Prunus amygdalus 	Feb 	light brown to brown pollen - not considered a good pollen source but bees are the primary pollinator	cultivated mostly in California	fair
Wild Cherry 	Prunus avium 	Apr - May 	yellow brown, light brown 	feral 	very good
Cherry Plum 	Prunus cerasifera 	 	light brown to brown 	feral 	fair
Sour Cherry 	Prunus cerasus 	Apr - May 	dark yellow 	ornamental and cultivated 	very good
Peach 	Prunus persica 	Apr - May 	redish yellow 	ornamental and cultivated 	good
Black Cherry 	Prunus serotina 	Apr - May 	 	feral 	minor
Blackthorn 	Prunus spinosa 	 	 	feral 	good
Pear 	Pyrus communis 	Apr - May 	red yellow 	ornamental and cultivated 	good
Oak 	Quercus spp. 	May 	 	feral 	
Oak 	Quercus robur, Quercus pedunculata 	May 	light olive 	feral 	minor
Black Locust 	Robinia pseudoacacia 	May - Jun 	 	feral 	
Blackberry 	Rubus spp. 	May - Jun 	light grey 	feral and cultivated 	
Raspberry 	Rubus idaeus 	May - Jun 	 	feral and cultivated 	good
Willow 	Salix spp. 	Feb - Apr 	lemon 	feral 	good
White Willow 	Salix alba 	 	 	feral 	good
Goat Willow 	Salix caprea 	Mar - Apr 	 	feral 	very good
Violet Willow 	Salix daphnoides 	Mar - Apr 	 	feral 	very good
Pussy Willow 	Salix discolor 	Mar - Apr 	 	feral and ornamental 	
Basket Willow 	Salix purpurea 	Mar - Apr 	 	feral 	very good
Silky leaf osier, Smith's Willow	Salix x smithiana 	Apr - May 	 	 	very good
American mountain ash 	Sorbus americana 	May-Jun 	 	feral 	
American Elm 	Ulmus americana 	Feb - Apr 	light grey 	feral 	
Winged Elm 	Ulmus alata 	Feb - Mar 	pale yellow 	feral 	good
Europea field elm 	Ulmus americana 	 	 	feral 	good
===Flowers and annual crop plants - Spring===
Common name 	Latin name 	Blooming months	Pollen color 	Availability 	Source for honeybees
Ajuga (Bronze Bugle, Common Bugle)	Ajuga reptans 	mid spring 	 	 	
Chives 	Allium schoenoprasum 	May - Sep 	 	cultivated? 	
Asparagus 	Asparagus officinalis 	May - Jun 	bright orange 	cultivated 	
Mustard 	Brassica arvenisi 	Apr - May 	lemon 	cultivated and feral 	
Canola 	Brassica napus 	May - Jun 	lemon 	extensively cultivated	very good
Yellow Crocus 	Crocus vernus (syn. Crocus aureus)	April 	orange yellow 	feral and ornamental 	fair
Leopard's Bane 	Doronicum cordatum 	Apr - May 	 	 	
Winter aconite 	Eranthis hyemalis 	Mar - Apr 	yellow 	feral and ornamental 	good
Snowdrop 	Galanthus nivalis 	Mar - Apr 	orange, red 	 	fair
Henbit 	Lamium amplexicaule 	April 	orange red, red, purplish red	Apr - Jul 	poor
White Sweet Clover 	Melilotus alba 	May - Aug 	yellow to dark yellow 	feral and cultivated 	good
Yellow Sweet Clover 	Melilotus officinalis 	May - Aug 	yellow to dark yellow 	feral and cultivated 	
Sainfoin 	Onobrychis viciifolia 	May - Jul 	yellow brown 	 	very good
Raspberry 	Rubus idaeus 	May - Jul 	white grey 	feral and cultivated 	good
Siberian squill 	Scilla sibirica 	Mar - Apr 	steel blue 	feral and ornamental 	good
White mustard 	Sinapis alba 	June 	lemon 	feral and cultivated 	good
Chick weed 	Stellaria media 	Apr - Jul 	yellowish 	feral 	minor
Dandelion 	Taraxacum officinale 	Apr - May 	red yellow, orange 	feral 	very good
==Summer==
===Trees and shrubs - Summer===
Common name 	Latin name 	Blooming months 	Pollen color 	Availability 	Source for honeybees
Horse chestnut 	Aesculus hippocastanum 	May - Jun after 80-110 growing degree days.	red 	feral 	good
Southern Catalpa 	Catalpa bignonioides 	Jun - Jul 	 	ornamental 	fair
Northern Catalpa 	Catalpa speciosa 	Jun - Jul 	 	ornamental 	
Bluebeard 	Caryopteris x clandonensis 'Heavenly Blue'	Aug - Sep 	 	 	very good
Virginia creeper 	Parthenocissus quinquefolia 	Jul - Aug 	 	 	good
Boston Ivy 'Veitchii' 	Parthenocissus tricuspidata 'Veitchii' 	Jun - Jul 	 	 	good
Sumac 	Rhus glabra 	Jun - Jul 	 	 	
Elder 	Sambucus canadensis 	Jun - Jul 	 	 	
Basswood or American Linden	Tilia americana 	Jun - Jul 	yellow to light orange	feral and ornamental	
Blueberry 	Vaccínium myrtíllus 	Jun 	red yellow, orange 	cultivated 	poor
===Flowers and annual crop plants - Summer===
Common name 	Latin name 	Blooming months	Pollen color 	Availability 	Source for honeybees
Allium 	Allium spp. 	 	 	feral and cultivated	
Onion 	Allium cepa 	 	light olive 	cultivated 	
Chives 	Allium schoenoprasum 	May - Sep 	 	feral and cultivated	
Garlic chives 	Allium tuberosa 	Aug - Sep 	 	feral and cultivated	
Leadwort syn. Indigobush	Amorpha fruticosa 	Jun - Jul 	 	ornamental? 	
Aster 	Aster spp. 	Sep-Frost 	reddish yellow 	feral and ornamental	
Land-in-blue 	Aster x dumosus 	Aug - Sep 	 	feral 	
Borage 	Borago officinalis 	Jun - Frost 	 	ornamental 	
Marigold 	Calendula officinalis 	Jun - Sep 	 	 	
Heather 	Calluna vulgaris 	Jul - Aug 	 	 	good
Hemp 	Cannabis sativa 	Aug 	yellow green 	 	good source
Blue Thistle 	Carduus spp. 	 	 	 	
Star thistle 	Centaurea spp. 	Jul - Sep 	 	 	
Knapweed 	Centaurea macrocephala 	Jul - Aug 	 	 	good
Knapweed 	Centaurea nigra 	 	very light olive 	 	
Chicory 	Cichorium intybus L. 	 	white 	 	
Cotoneaster 	Cotoneaster spp. 	 	 	 	good
Cucumber 	Cucumis spp. 	 	pale yellow 	cultivated 	
Melons 	Cucumis melo 	Jun-Frost 	pale yellow 	cultivated 	
Pumpkin 	Cucurbita pepo 	Jun-Frost 	bright yellow 	cultivated 	
Fireweed 	Epilobium angustifolium 	Jul - Aug 	blue 	feral 	
Joe-Pye weed 	Eutrochium spp. 	Aug - Sep 	 	 	
Buckwheat 	Fagopyrum esculentum 	Jul - Aug 	light yellow to light green	cultivated 	good source
Blue vine 	Gonolobus laevis syn. Cynanchum laeve	 	 	 	
Sunflower 	Helianthus annuus 	Jun - Sep 	golden 	feral and cultivated	
Jewelweed 	Impatients capensis 	 	yellowish white 	 	
Alyssum 	Lobularia maritima 	Jun - Sep 	 	 	
Mallow 	Malva alcea 	Jun - Sep 	 	 	
Alfalfa 	Medicago sativa 	July - Aug 	greyish yellow 	feral and cultivated	
Clover 	Melilotus spp. and Trifolium spp. 	May - Aug 	 	feral and cultivated	
White Sweet Clover 	Melilotus alba 	 	 	feral and cultivated	
Yellow Sweet Clover 	Melilotus officinalis 	 	 	feral and cultivated	
Basil 	Ocimum basilicum 	 	 	ornamental 	
Poppy 	Papaver somniverum 	May - Jun 	grey 	feral and ornamental	very good source
Smartweed 	Polygonum spp. 	Aug - Sep 	 	 	
Chickweed 	Stellaria media 	Apr - Jul 	 	 	minor source
Germander 	Teucrium chamaedrys 	Jul - Aug 	 	 	
Alsike Clover 	Trifolium hybridum 	 	yellow brown 	 	good source
Crimson Clover 	Trifolium incarnatum 	 	dark brown 	 	
White Clover 	Trifolium repens 	Jun - Jul 	yellow brown 	 	good source
Cat-tail 	Typha latifolia 	Jun - Jul 	 	 	
Common vetch 	Vicia cracca 	Jul - Aug 	 	 	
Spring Vetch 	Vicia sativa 	Jul - Aug 	 	 	
Sweet Corn 	Zea mays 	Jun - Jul 	yellowish white 	cultivated 	
==Fall==
===Trees and shrubs - Fall===
Common name 	Latin name 	Blooming months	Pollen color	Availability	Source for honeybees
Chinese Elm, Lacebark Elm	Ulmus parvifolia	Aug - Sep 	 	ornamental 	good
===Flowers and annual crop plants - Fall===
Common name 	Latin name 	Blooming months	Pollen color 	Availability 	Source for honeybees
Aster 	Aster spp. 	Sep-Frost 	reddish yellow 	 	
Borage 	Borago officinalis 	Jun - Frost 	 	 	
Melons 	Cucumis melo 	Jun-Frost 	 	cultivated 	
Sweet autumn clematis	Clematis ternifolia	late Sept 	white 	ornamental 	
Pumpkin 	Cucurbita pepo 	Jun-Frost 	bright yellow 	cultivated 	
Ivy 	Hedera spp. 	Sep - Oct 	dull yellow or black?	ornamental (not native to America)	
Goldenrod 	Solidago spp. 	Sep - Oct 	golden 	feral 	
== References ==
Source: Bienenweide Arbeitsblatt 207, Bieneninstitut Kirchhain, 2001
==See also==
*Nectar source
*Forage (honeybee)
*List of honey plants
==External links==
*The R-Values of Honey: Pollen Coefficient accessed Feb 2005
*Some Ohio Nectar and Pollen Producing Plants Ohio State University Extension Fact Sheet, 2000, Dr. James Tew 
* Honey Plants Flowering Plants/Trees Dana Stahlman, 2004
*The pollen loads of the honeybee, Dorothy Hodges, Bee Research Association Limited, London, 1952
*Bienennährpflanzen 1 : Gehölze Nov 1999, Thomas Lamp; accessed 05/2005
Category:Pollination