Sunflower Bee Facts

General Facts

Sunflower Bees belong to the family Megachilidae and are members of the Megachile genus. they are non-aggressive and non-colonizing solitary bees that pollinate everything in the sunflower family and various fruits and veggies. They are black with yellow stripes and look similar to large leaf cutter bees.

What do Sunflower Bees Pollinate?

Sunflower Bees are generalists; they don’t stick to certain blossoms they pollinate whatever they find and like. Continued studies are being done on this bee. We know they pollinate everything in the sunflower family and various fruits and vegetables.

How many Sunflower Bees do I need?

A single  female Sunflower Bees visits around 112,000 blossoms per day where as a honey bee visits 50-1000. This means they pollinate over 100% more effectively and efficiently than honey bees. We recommend having 5 tubes of bees for 100 square feet of garden space (10×10 garden area). If you need help knowing what you need see our step by step guide.


Sunflower Bees are summer time pollinators. They incubate for 20-28 days at 70*F+ and emerge mid to late July. They pollinate summer blossoms and don’t venture more than 400 yards from their nest; usually staying with in 200 feet. Their average nesting season is 8-12 weeks, after which they die. Their offspring will mature over the winter and emerge again next summer to pollinate.


There are 3 essential items for prime Sunflower Bee habitat, 1. nesting place, 2. pollen, and 3. a mud and leaf source. They will only remain in an area if they have a proper habitat.

  1. Best nesting place for Sunflower Bees are in reed tubes;  To read more on nesting materials  click here.
  2. summer time pollen source: flowers, fruits, vegetables ect…
  3. They use a mix of both leaves and mud to form a pulp they use to separate cells and plug nest entrances.

If you have these 3 items than you are ready for Sunflower Bees!

How you know  your bees are working:

When honey bees are pollinating  you can see huge swarms of bees around the tree.   Sunflower bees are sometimes harder to spot. Some signs that show your bees are working include: new tubes being filled with clay, activity around the bee house, spotting bees on the blossoms, or flying around (though they are harder to spot),  Beautiful flowers and better tasting bigger vegetables at the end of the season.

If you feel there is a problem with your bees check out our troubleshooting page here.

Storing the Bees:

Sunflower Bees need to be kept in a cold place to properly mature. Once you receive your bees keep them in a cold place such as the fridge, garage or cold storage. Store them below 40*F so they stay in hibernation from fall to spring. WARNING: If cocoons’ temperature exceeds 44*F for extended period of time they will not hibernate properly which may result in premature emergence and/or death.

Keep bees in cold hibernation until the temperature outside consistently exceeds 70*F and your blossoms begin to develop. Then it is time to place your bees in their bee house for releasing.

Setting up the bee house:

Place house facing between south and east. Bees are cold blooded and need the morning sun to warm them to begin flying. Bee houses should be in a secure place such as a tree, fence post, side of a house, barn or shed. Make sure bee house is at least 3 feet off the ground to deter ants. If you have squirrels in the area you may want to squirrel proof the houses with chicken wire.

Take Down and Winter Prep:

Osmia species require winter temperatures for successful emergence the following summer. Sunflower Bees will  usually pollinate until the first frost. In September, or after the first frost, take down the house (or cover) and place in a cold place until next spring. This will help keep parasites/predators away. If house is taken down early it can dislodge the larva from their food, be sure to store with their food at all times. This is also the best time to replace used reeds and purchase new bees. To learn how to replace reeds click here.