Monarch Watch Milkweed Market

Below are some answers to frequently asked questions and additional information about milkweed and our Milkweed Market. Thank you for your interest!

About the Milkweed Market

Monarch butterfly numbers have been at an all time low for the last two overwintering seasons, and many pollinators are declining as well. The widespread planting of herbicide tolerant crops, intensive farming, and the ethanol mandate has led to a rapid loss of habitat. Monarchs and pollinators need our help. By planting milkweeds – the host plants for monarch caterpillars – and nectar plants for adult monarchs and pollinators, you can help maintain the monarch migration and sustain the pollinators whose pollinating services maintain our ecosystems.

We are contracting with native plant nurseries to increase our impact nationwide and continue to seek new partners.

In order to keep many species in the Milkweed Market available, we rely on local seed collections from across the country. We have created a Milkweed Regions & Seed Needs section of our Bring Back the Monarchs program. We really need your help to keep this program going! We welcome any questions, comments, or suggestions regarding the new Monarch Watch Milkweed Market. Please feel free to contact us anytime.

Contacting Us

Milkweed Market


Phone: 1-785-864-4441
Please keep in mind we are a nonprofit and have limited resources available to answer the phone. If we do not answer please leave a message and we will respond as soon as possible.

Online: View your order history, order statuses, review order details, as well as manage your account information.

Milkweed Market
c/o Monarch Watch
2021 Constant Ave
Lawrence, KS 66047

How do I treat milkweed plants that have aphids?

Like many insects that forage on milkweed, Oleander Aphids have adapted the ability to tolerate the toxins in milkweed plants.

The good news is that aphids are not a direct threat to monarch eggs or larvae. Aphids will feed on the milkweed plant only; they won't spread to your other plants. They only tend to be problematic is the plant is very small or weak. In these cases, they may weaken the plant even further and greatly decrease the nutritional value for your caterpillars. We have had larger caterpillars eat the plant aphids and all!

It is nearly impossible to get rid of aphids. Lady bugs are nice because they eat the aphid but not the larvae. Of course catching enough lady bugs to solve the problem is more than time consuming- and it can be pricey to purchase them from a biological control supplier. Also, the lady bug larvae do eat the monarch eggs.

The easiest way to control aphids is to use the hose to blast them off every couple of days. You won't completely get rid of them, but it helps. You can spray them with hot, soapy water. This should kill them on contact.

Try this "Contact Only" mix (This was shared with us by Vic Jost @ Jost Greenhouses through Elliott Duemler at Taylor Creek Nursery).

• 1 part (e.g. 1 oz) Blue Dawn
• 1 part Isopropyl Alcohol
• 1 part white vinegar
• 128 parts (e.g. 1 gal) water

"Contact only" means that the insects have to have the mixture applied to their body for it to work.

Once you see that the mixture is working, as an extra precaution you can then rinse the plants so that they are safe for monarch larvae.

As a last resort, you can wear rubber gloves to smash the aphids. The gloves keep your fingers from getting stained orange.

Don't smash the aphid mummies! They contain beneficial wasps!

How Many Plugs Should I Plant?


For gardens, we recommend that you plant about 20-30 milkweed plants per 100 square feet. Milkweed plants should be spaced 1 foot apart, placed in clusters of 3-4 milkweeds. The clusters should then be interspersed with nectar sources that bloom at various times of the growing season (See our plant lists here This will supply nectar for mating and migration in adults. Common milkweed will tend to spread by underground rhizomes, so 30 plants might be too many. If you like a “tidy” garden, your garden plan should include pulling or digging out common milkweed from areas that it may not be wanted. Check for monarch eggs before discarding plants, and place the leaves with eggs on or near a plant that you did not remove.


For restoration of natural areas, if planting common milkweed, we recommend 20-40 plugs per acre, maximum. Swamp milkweed, which does not reproduce by underground rhizomes, can be planted at up to 80 plants per acre, maximum. There is no hard and fast rule, so there is some flexibility. You will want to disperse clusters of 3-4 plants among nectar sources focusing on native, perennial grasses and flowers. Planting milkweed in large, continuous patches is not recommended. This allows predators and parasites to find the caterpillars more easily.

Tropical Milkweed and OE

Think of milkweed — all of it, not just the non-natives — as a potential vector for the monarch disease commonly known as “OE.” Just like hand rails carry the common cold virus, any milkweed can carry the protozoan spores for OE, which come from the butterflies. Because people touch hand rails often, they are a good vector for the cold. Many have observed that the monarchs prefer the A. curassavica over native species, so there may be a higher concentration of potential diseases on these plants than on the native plants. In warm climates, this problem is multiplied by a lack of winter freeze that causes all tropical milkweed to die back. Balloon plant (A. physocarpa) does not tend to attract monarchs as much, and no known problems are associated with it. We feel the issues with OE are limited to a very very small portion of the United States. We encourage people to participate in the Monarch Larva Monitoring Project if they are raising monarchs, to help monitor the spread of the disease.

Here is a concise, science-based Q&A about tropical milkweed and OE:

The take-home message is in the answer to question #7

• Plant native milkweeds whenever possible.
• If you have tropical milkweed, cut it back from October-February to within 6” of the ground (unless it dies back naturally on its own). Also remove any new plant growth at the base of the plant. If you live in a warm coastal area in the southern U.S. or California, cutting the milkweed back is especially important and it will be necessary to prune frequently (every 3 weeks) as it quickly re-grows.
• Consider gradually replacing your tropical milkweed with native species.

Monarch Watch does not sell tropical species of milkweed, except in very small quantities at our Spring Open House in Lawrence, KS.

Where can I find smaller quantities of milkweed plants?

If you are looking for a smaller amount of native milkweed, please see our list of vendors who sell milkweed and search for a vendor in your area.

Where can I get milkweed seeds?

You can search for local genotype seeds through the Xerces Society:

Gardening resources

Thanks for your questions about planting a pollinator/monarch garden. In addition to the information on our website, Monarch Joint Venture has some great gardening resources.

Texas plant list:

Check the BONAP maps to determine what milkweed is native to your area. Light green counties are where that species of milkweed has historically been found.

Canadian Requests

Unfortunately, Monarch Watch cannot ship live milkweed plants to Canada.

We have some Canadian plant vendors listed on our Milkweed Market page. The Xerces Society also has an online tool for finding milkweed seeds, which may include Canada.

The Wallace Springs Eco-centre is doing seed collection and distribution. They are on Facebook.

The David Suzuki Foundation is also working in the Toronto area to restore milkweeds, and could be a great resource.

How can I help monarchs?

Planting native milkweed and plenty of other nectar plants are the best things that you can do to save the monarch migration. Our Milkweed Market plants are too small in the first year to support a large number of caterpillars. They are intended to grow to become monarch habitat, and this takes time.

FYI: To track this migration and the emergence of milkweed, go to the Journey North website and click on the monarch image.

Another great thing you can do for monarchs is to collect wild eggs and rear them indoors. This protects monarchs that might otherwise be subject to predation and parasitism. It is estimated that less than 1 in 100 monarchs survive in the wild, and bringing them indoors can help. They may still get a disease, and you may still see mortality.

Purchasing monarch larvae is a great way to educate students of all ages about monarch biology when wild caught eggs are hard to find. Education is the primary focus of our monarch rearing kits. However, we do not intend for our rearing kits to be used as a conservation effort. Releasing lab-reared monarchs into the wild neither helps nor hinders the population. Remember, if you are purchasing a Monarch Rearing Kit for personal use, there may be fewer rearing kits available for educational purposes. And, only purchase rearing kits if you have sufficient milkweed to feed them.

GMO Milkweed

There are no (zero) transgenetic (GMO) native plants of any kind, milkweed or otherwise. The only genetic modification of native plants is through tens of thousands of years of natural selection. This is why they do so well in their native environment and require less maintenance than cultivated plants. Nature has selected them over time to endure your local conditions.

The plants that we distribute through Monarch Watch's commercial nursery partners are grown from wild milkweed seed that people like you collected and sent to us, or they are purchased from native plant seed distributors. We label each collection with the source information, send the seed to the nursery, and they carefully trace each seed source so that the plants remain in their native habitats. This is truly a grass-roots effort to restore habitat to areas where milkweed has been removed.

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