Grower Frequently Asked Questions
- What is Integrated Crop Pollination?
- How can I ensure consistent, reliable pollination?
- How can I assess pollination on my farm?
- What kinds of bees pollinate crops? Are some bees better pollinators than others?
- I want to use blue orchard bees. What do I need to know?
- Where can I find a sample pollination contract?
- What are general guidelines to keep bees safe when I’m managing crop pests and diseases?
- Is it safe to spray during bloom?
- Where can I find more information on pesticide toxicity to bees?
- Are fungicides toxic to bees? Can I spray fungicides during bloom?
- I want to plant wildflowers for bees on my farm. What do I need to know?
- Will a wildflower planting compete with my crop for pollinators?
- What kind of technical and financial support is available for farmers interested in wildflower plantings?
- What other things can I do besides installing a wildflower planting that will support bees on my farm?
1. What is Integrated Crop Pollination?
Integrated crop pollination is the combined use of multiple pollinator species, habitat augmentation, and crop management practices to provide reliable and economical pollination of crops.
Pollinator species can include managed honey bees, alternative managed bees, and many different types of wild bees. Habitat augmentation refers to adding floral and nesting resources to farms (e.g. wildflower strip, meadows, and hedgerows). Crop management practices that support pollination include modifying pest management practices to reduce risks to pollinators, no-till farming to protect ground-nesting bees, and allowing cover crops to bloom to provide bees with additional food resources. Reliable and economical pollination may come from honey bees alone or from a combination of different pollinators. The optimal combination of pollinators and pollination strategies will depend on the crop, the farm situation (e.g. management practices and where your farm is located), and the economics of different approaches.
Pollinators require food (pollen and nectar), nesting habitat, and a safe environment protected from pesticide exposure. Farmers can support pollinators by using practices that provide these requirements. In some cases, adding more honey bees can improve pollination. In others, diversifying your crop pollinators and implementing farm practices that support those pollinators can ensure that the bees on your farm stay abundant and healthy and continue to pollinate. Project ICP is developing a Guide to Integrated Crop Pollination that will be available on this website when it is published. Visit the project website Resources for Growers page for more information on integrated crop pollination.
2. How can I ensure consistent, reliable pollination?
Consistent, reliable pollination depends on having enough of the right kinds of bees to pollinate your crop – even when weather conditions vary. The trick is to figure out how many bees are enough to provide optimal pollination, and then determine how you can best support enough of those bees to make sure they’re healthy and working hard. To learn more about the pollination needs of almond, apple, cherry, blueberry, watermelon and pumpkin and how to support crop-pollinating bees watch the ICP Webinar series.
3. How can I assess pollination on my farm?
Pollination records allow you to keep track of your pollination investment. At minimum, consider keeping records of the following: crop type and variety, field name, managed bee stocking rates and honey bee hive strength, weather conditions during bloom, and yield. This guide from Oregon State University Extension shows how to monitor hive strength. Other factors to note include dates when bloom started, peaked, and ended, the dates you placed managed bees and removed them, any pesticides applied within 2 weeks of bloom or during bloom, and crop flower visitation rates. You can determine crop visitation rates by counting the number of bees visiting your flowers along a crop row using this guide and data sheet. By keeping these records annually for different fields, you can look back to see what did and didn’t work for optimizing pollination during bloom. The Integrated Crop Pollination project is developing bee monitoring tools for some key specialty crops. If you grow watermelon in the Mid-Atlantic region or in California, you can use this monitoring guide to determine the contribution of wild bees to your crop pollination.
4. What kinds of bees pollinate crops? Are some bees better pollinators than others?
Both managed and wild bees can pollinate crops. The managed European honey bee is the dominant crop pollinator on most commercial farms. The advantage of this species is that it can be managed in large, social colonies, placed at the edge of a crop field at the start of bloom, and removed from the field at the end of bloom. Some bees are more efficient pollinators than honey bees, moving more pollen per visit or per day between crop flowers, but honey bees can make up for this in sheer numbers in a hive.
Some growers also use alternative managed bees by purchasing managed bumble bees or managed orchard bees. Bumble bees are large and have the ability to buzz pollinate, or vibrate their flight muscles to release pollen from flowers, and therefore tend to move a lot of pollen from flower to flower of some crops such as blueberry. Managed bumble bees colonies are smaller than honey bee colonies. They last one growing season, and are therefore disposable, meaning that new colonies need to be bought annually. Orchard bees are a group of bees that make their nests in reeds or paper straws above ground. They are most often managed to pollinate non-citrus fruit trees, but are also being developed for commercial almond and raspberry pollination. These bees are solitary and only live one season, but their nests and progeny can be carried over to the next season. Orchard bees are placed in fields at lower stocking rates than honey bees because they are much more efficient pollinators of fruit trees, plus they fly and forage in chilly weather.
Finally, you are likely to find some wild bees visiting and possibly pollinating your crop. There are an estimated 3,600 named species of native bees in the United States, some of which are abundant and efficient crop pollinators. There are wild bumble bees, wild orchard bees, sweat bees, leafcutter bees, long-horned bees, and digger bees, to name a few. Some crops that originated in the United States (e.g. sunflower, pumpkin, cranberry and blueberry) have wild bees that specialize on those crops.
5. I want to use blue orchard bees. What do I need to know?
Blue orchard bees (Osmia spp.) are being developed for a number of specialty crops, including almond and raspberry. These bees are solitary bees that build their nests in cavities above the ground and partition nest cells with mud. You can purchase bees and supplies from a blue orchard beekeeper, and there are a few of these that provide the bees and some expertise. See the publication How to Manage the Blue Orchard Bee or visit the Orchard Bee Association website to find out more. Talk with your blue orchard beekeeper to ensure that you are purchasing pathogen-free blue orchard bees from your region, to avoid moving subspecies outside of their range and spreading pathogens. Make sure mud is available when bees are placed in your orchard. As with all bees, be sure to minimize risk associated with pest management practices. If managing these bees yourself, be sure to follow proper sanitation practices to avoid disease, parasite, or pathogen-caused population collapses.
6. Where can I find a sample pollination contract?
Here is a sample pollination agreement developed by the University of Florida. The free-downloadable book, “Managing Alternative Pollinators” also has a sample contract on page 13. Your beekeeper may have a sample agreement that they use already. Pollination agreements allow both parties to agree to expectations and avoid conflict – benefiting both the crop and bees.
7. What are general guidelines to keep bees safe when I’m managing crop pests and diseases?
Use chemical control only when biological, mechanical, and cultural options have been exhausted. Avoid pesticide applications during bloom, including bloom under the crop canopy (see question 8). If chemical control is needed, apply at night or when air temperature is below 50°F. Choose the least toxic pesticides and formulations (see question 9 and resources below). Minimize drift outside crop fields, especially if flowering weeds are present in field borders. Remove weed flowers from crop fields before applying pesticides; for example, by mowing row middles before spraying. Provide flowering habitat away from crop fields to attract bees and provide them with a safe refuge during the times of the year when fields are being treated for pests and diseases. Most importantly, use integrated pest management (IPM), including careful scouting and monitoring of pests and diseases, to decide when and where control of target pests and diseases is needed. Learn more about how to minimize risks to bees by reading this MSU extension article.
8. Is it safe to spray during bloom?
Crop bloom is the time when bees are active in fields and most likely to be exposed to pesticide applications. Whenever possible, it is best to avoid spraying during bloom, as even plain water can knock down bees in flight. However, for some crops, it can be hard to avoid treating certain pests or diseases during bloom. If pesticide applications cannot be moved outside of the bloom period, apply at night or when the air temperature is below 50°F to reduce the chances of exposure. Use insecticides with a brief half-life (knock down) that will be safe by morning. Always read and follow pesticide label instructions and restrictions; many bee-toxic products cannot be used during bloom. Choose the least toxic options available for controlling a target pest.
9. Where can I find more information on pesticide toxicity to bees?
There are several guides that rank different pesticides by their toxicity to bees. Most of these rankings are based on the contact toxicity to adult honey bees, not how toxic the chemicals are when ingested by adult bees, fed to young bees, or exposed to non-honey bees.
- UC IPM Bee Precaution Pesticide Rankings (University of California). A searchable database that allows you to compare different pesticides based on their toxicity to adult honey bees.
- How to Reduce Bee Poisoning from Pesticides (Oregon State University). This guide also offers a free mobile companion app that allows you to search the tables of pesticide toxicity by trade or chemical name from your phone or tablet.
- Minimizing Pesticide Risks to Bees in Fruit Crops (Michigan State University)
Contact your local county Cooperative Extension office for additional resources, educational programs, and assistance with questions about pest and disease management and pesticide toxicity to bees.
10. Are fungicides toxic to bees? Can I spray fungicides during bloom?
Recently, researchers found that certain fungicides are toxic to bees, either alone or when applied in combination with insecticides. Some fungicides can cause direct mortality, particularly to larvae, while others impair immune response, alter foraging behavior, and/or reduce production of bee bread (food for young bees) in honey bee colonies. Fungicides that exhibit toxicity to bees include trade names that contain captan, chlorothalonil, and mancozeb. Avoid tank mixing insecticides and fungicides, particularly mixes of pyrethroid or neonicotinoid insecticides with DMI fungicides (including those that contain the following active ingredients propriconazole, tebuconazole, and myclobutanil; see this list under FRAC Code 3 for more examples), as mixing chemistries can increase their toxicity to bees. Avoid applying fungicides during bloom to minimize the risk of interactions with other pesticides, including in-hive miticides, that bees may be exposed to.
11. I want to plant wildflowers for bees on my farm. What do I need to know?
Reduced mowing on field edges can provide flowering plants for bees, but these areas are often invaded quickly by grass, reducing their value to pollinators. There are many other ways to add flowers to your farm for bees, and these will last longer and provide more concentrated resources for bees. These include flowering cover crops, perennial wildflower plantings, and hedgerows. Plan ahead with these key steps: 1. Select a site where the flowering resource will have the most success – choose sites where aggressive weed pressure is minimal and where flowers will be protected from pesticide exposure, both from drift and runoff from crop fields. 2. Thoroughly control weeds prior to planting to ensure success. 3. Choose a plant mix adapted to your region and suitable for the site conditions (for some ideas, see the Xerces Society recommended seed mixes for different North American regions). Avoid potentially weedy species for your area. 4. Continue managing weeds after seeding for long lasting, successful wildflower stands. For more information watch Five Steps to Success for Establishing Perennial Wildflower Plantings for Pollinators.
12. Will a wildflower planting compete with my crop for pollinators?
Wildflower plantings do not seem to compete with highly attractive crops; bees visited wildflowers next to California almond orchards, but this did not negatively impact crop visitation. For crops that are not very attractive to honey bees (e.g. blueberry, onion seed) we recommend tailoring your plant mix to provide flowers for bees before and after crop bloom, to avoid any issues with competing blooms. This can help young mother bees choose and prepare nests and mature their first eggs prior to crop bloom and will provide them with resources to feed additional offspring for the weeks after the crop stops flowering. In addition, managed honey bee colonies are often healthier and more resilient to disease and pesticides if they have access to a diverse pollen diet. If you are concerned about competition, you can high-mow wildflowers at the start of crop bloom. Consult with your local NRCS office, farm advisor or a local plant expert to help develop a mix tailored for your crop and region.
13. What kind of technical and financial support is available for farmers interested in wildflower plantings?
The USDA Natural Resources Conservation Services (NRCS) and Farm Service Agency (FSA) both provide technical and financial support to farmers interested in adding wildflower plantings to their farm. This document provides an overview of farm bill programs for pollinators. To learn more about programs available in your area, visit your local county USDA Services Center to talk with NRCS and FSA staff. Resource conservation districts and a number of non-profit organizations (the Xerces Society, Project ApisM, and Pheasants Forever) also provide technical support for growers.
14. What other things can I do besides installing a wildflower planting that will support bees on my farm?
Maintain any existing areas with wild flowering plants, including trees and shrubs. Protect these areas from pesticide exposure, including drift and runoff. Consider increasing the diversity of flowering plants in these areas by removing aggressively, invasive plants and making room for native species to grow. Reduce mowing, disking, and tilling of field borders to allow flowering plants to grow and to protect bees that nest underground. Take steps to minimize the risk of your pest management program to bees – especially risks associated with pesticides. During hot weather provide clean, pesticide-free sources of water for honey bees around your farm. For more ideas visit the Resources for Growers page on this website.