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Frequently Asked Questions
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Planting & Pesticides

Is there any value to planting a garden of solely milkweed or do I have to mix in other flowering species to make a beneficial habitat?

 Having a garden full of milkweed is beneficial for monarchs. The best habitat for monarchs, however, contains a variety of native milkweed as well as nectar plants. While milkweeds are the only plants that monarch larvae can eat, the adult monarchs themselves do not eat only milkweed. Instead, they rely on the nectar from flowers. Having a combination of milkweed and other flowering plants helps ensure that adult monarchs will have a food source even when the milkweed plants are not in bloom. To find out what nectar and milkweed plants to buy visit Xerces Society’s Nectar Guides and our Plant Milkweed for Monarchs handout.

How can I encourage the sale of pesticide-free milkweed?

Insecticides are known to reduce monarch caterpillar growth and survival and affect butterfly flight and navigation. It is critical to avoid using pesticides, especially systemic insecticides, on milkweed and nectar plants and to use an integrated pest management approach. Systemic insecticides, such as neonicotinoids, are generally harmful to monarchs and other beneficial insects, and have persistent effects that last long after the plants are purchased. Read more about concerns with monarchs and pesticides here.

Well-educated consumers can really make a difference in driving demand for pesticide-free plant materials. In order for companies that grow and sell plants to justify an investment in different species or techniques, they go through an intensive process trying to evaluate the short- and long-term market to determine how profitable (or not) that investment will be.

Raising your voice is an important way that you can show demand for pesticide-free milkweed. Use the resources below as tools to reach out to your nursery and express your desire to purchase pesticide-free milkweed. You can do this by asking to speak to the store manager, submitting an inquiry on the store website, posting a review on the internet, or any other venues available to contact the store management.

If you believe you have purchased treated plants, contact the store you purchased the plants from to find out, and if so, express your desire for pesticide-free plants. This will help them know that their consumers do not want to purchase treated plants. You can also find more pointers for what else you can do here.

Where can I find resources to create a pollinator plan?

There are lots of resources that can be used to put together a pollinator plan. The MJV Monarch Conservation Implementation Plan is an annually updated plan that is publicly available to download. This plan identifies and prioritizes monarch conservation action items in the U.S. and can be used to guide your own planning and conservation, whether you are planning for monarch or pollinator education, habitat conservation, research or all three! If you're looking for more information and planning guides, visit the MJV Downloads and Links page under 'Conservation Plans.'

Is it better to plant seeds or plugs for my monarch habitat project?

Many factors play into the decision of whether seeds or plugs, or some combination of the two, are more appropriate for your habitat project. Seeds are often the most economical option, but establishment may be more successful with planting plugs if your project budget can handle it. If an area is large, using a diverse native seed mix will require less time, whereas it will require significantly more time and labor if transplanting plugs throughout the entire area. For smaller areas, like gardens, placement of different species within the habitat might be more important to you and in this case, plugs might be a more appropriate option (because you have more control than a seed mix). Plugs have a head start and generally establish and reach maturity more quickly than seeds.

You can explore what works best for different species, and could find that a combination of techniques works best, depending on the species you are planting, the location and size of the project, the project budget, and the labor or equipment resources available to support the project. To save cost but maintain the higher success of plug establishment, some start seeds indoors (or in controlled containers outdoors) which they later transplant as plugs. Some plant a diverse seed mix and supplement it with plugs. Others stick to just using one technique or the other (plugs or seeds). Each habitat project is unique and there is not one best option that fits the needs of all.

A consideration for all habitat projects is site preparation prior to planting. To give seedlings and plugs the best chance of survival, it is important to keep weed pressure low. Ensuring that weeds and weed seeds are eradicated from the site prior to planting will improve the success of establishing native plants. 

Visit our resources page for additional information on this topic.

What should I do if plants that I've purchased were treated with neonicotinoids or other pesticides? How should I avoid purchasing treated plants in the future?

When creating pollinator habitat it is important to minimize pollinator exposure to chemicals that have the potential to cause harm.  There are several steps that you can take as a consumer to reduce pollinator exposure to neonicotinoids and other pesticides:

Scenario 1: You have already purchased plants, but you suspect or don’t know if they were treated.  First of all, contact the store to ask if they have been treated. If they were treated, express your desire for them to sell pesticide-free plants. Consumer demand is a critical driver of change in a business setting. If you know or are suspicious that recently purchased plants were treated, you have a couple options. For nectar plants, remove flowers for the first couple of years so that pollinators are not attracted to blooms. Neonicotinoid levels will diminish in the plant over time. For caterpillar host plants like milkweed suspected of being treated, the safest option for would be to properly dispose of the plant and find sources you know are pesticide-free to replace them. Alternatively, you could cover/tent plants for a year so that monarchs do not use them. By the next year, it is unlikely that there will be enough remaining pesticide residue to pose a problem to caterpillars. However, this is an active area of research and later findings might lead to changes in this recommendation.

Scenario 2: You’re planning to purchase milkweed and other wildflowers to support pollinators.  Sometimes plants are labeled as neonicotinoid- or pesticide-free, but not always. Even if plants are labeled as “Pollinator Plants” it is best to ask the grower or distributor you are purchasing from about the history of the plants. Ask if they were treated with any pesticides and if so, which ones. Express the importance of pesticide free plants to help plant producers understand the demand for pollinator-friendly plants in the marketplace. Be wise about purchasing plants, ask the appropriate questions, build a relationship with producers you trust, and encourage your community to support those producers you know are growing/selling neonicotinoid free plants.

Scenario 3: You’re maintaining pollinator habitat on your property.  As you maintain pollinator habitat on your property, do not use insecticides on your plants.  If you must treat, do not use neonics or other systemic insecticides, and avoid spraying when plants are in bloom, when pollinators are most drawn to them. The use of insecticidal soaps or horticultural oils can be used to control unwanted insects, but keep in mind that this treatment may harm or kill any beneficial insects present at the time of application, even if the plant is not in bloom.

What are the current recommendations for minimizing pesticide drift onto monarch habitat?

The Natural Resources Conservation Service Wildlife Habitat Evaluation Guide recommends including a 125-foot pesticide free buffer adjacent to monarch or pollinator habitat to minimize impacts of drift. Using best practices when applying pesticides will further minimize the risk of drift. Drift distance will vary greatly depending on method of application and conditions during application.

What should I do if I can't find an appropriate source of local native milkweeds or nectar resources that are recommended for monarchs?

This reason for this problem comes back to the principles of supply and demand. The commercial availability of native milkweeds and nectar sources is driven by the demand for those resources and a response in the supply chain will not always be immediate. Producing native plant materials is a long-term process and can sometimes be a risky investment for plant producers if they aren't sure about the long-term demand for those plants/seeds. It is important that we continue to drive increasing demand for these native, locally sourced plant materials to increase their availability over time and hopefully to drive down the cost as well. Since supply is often limited for native milkweeds and nectar sources, get your orders/requests in early. If vendors sell out during the spring, they may begin taking pre-orders for the following fall or spring.

If you haven't already done so, make sure that your site is ready for planting. There are different methods for site preparation, such as solarization, you can use to ensure the area is as weed free as possible to increase the success of the native plants you are trying to establish. Even if native milkweeds are not available when you are ready to plant, establish a high-diversity mix with other native forbs and grasses. These habitats will still be beneficial to monarchs and other pollinators, and you can plan ahead to augment the habitat in years following with milkweed plants/plugs. Another option would be to use annuals or some sort of cover crop on the habitat area during that season. This could prevent weedy species or invasives from taking over a site that you have prepared for planting and will allow time for you to find an appropriate source of seeds or plants for the habitat. Depending on what is planted, it may also provide some floral resources for pollinators.