Category Archives: Gardening

Help monarch butterflies by giving away milkweed plants

Like most monarch fans, I dutifully pack my yard with milkweed and hope the offering will somehow offset the effects of habitat loss and pesticide applications on population levels. But I’m not a complete idiot so I know that my contribution is probably rather inconsequential. Planting milkweeds for a few dozen monarchs is not really going to help population declines.

So this year I finally got around to something I’ve been meaning to do for years: give away lots of milkweed plants. My goal was to distribute free seedlings to several hundred people in my town (Swarthmore, Pennsylvania), ideally creating a concentration of milkweed that might make a difference. And because milkweeds are perennials and produce seeds that disperse with the wind, all of those initial milkweeds would do their reproductive duties for years, seeding vacant lots and such. Perhaps after a few years we will start seeing flocks of monarchs again (I’m an optimist).

This post summarizes how I grew the plants and gave them away, just in case anyone else might be nudged to do something similar. If one person in every town did this we might reverse the yearly declines in monarch populations.

Step one was to collect seeds. If you’ve never done it before it’s easy — just pick browning pods and let fully dry. Here’s a photograph from 2018 showing some swamp milkweed pods:

You don’t need to, but I decided to clean my seeds. Here’s the end product:

Milkweed seeds germinate best if they are exposed to a period of cold, ideally when moist. So all I did was scatter the seeds on a few large containers (actually, unused litterboxes). Come spring I had hundreds of seedlings emerge.

As seedlings emerged I’d transfer them to small Dixie cups. I soon covered almost every square inch of sunny space in my yard. (That’s my bee hotel, by the way.)

Then I started giving them away to people in town who had expressed an interest in growing milkweed. I put the seedlings into cheap paper cups and then delivered sets of threes to doorsteps. This used up about two dozen seedlings.

To get people to plant milkweed I thought it might be fun to leave pots around town along with, “please adopt us” notes. I gave away probably 100 this way. Usually the pots would be taken within an hour or so. It was fun leaving them in obscure spots around town, and I was hoping to build some curiosity about who was doing this and why.

Here’s the note I left with each set. I went with “rose milkweed” because I worried that “swamp milkweed” might be a turn-off for some. But same plant: Asclepias incarnata, my favorite milkweed. And it’s native.

Here are seedlings bound for one of the giveaway events. There were even more pots in the front.

Here’s my display table. I held the events on days when large crowds would be expected, so probably 95% of takers were people who didn’t realize they even wanted milkweed plants.

In total, I probably gave away 500 milkweed plants this year. I’m not positive it was a success but I think I noticed more monarchs around town this year. As anecdotal evidence, I wasn’t even trying to photograph a monarch when taking this picture:

If you have milkweed plants and seed pods, give it a try in 2020. It would be especially good if garden clubs across the country made this a priority.

Spotted lanternfly photographs

I’ve posted a few pics of the invasive spotted lanternfly (Lycorma delicatula) on Instagram but thought I’d feature my full collection in a post. The insect is extremely photogenic but it’s also good to let people know what different stages look like so that everyone can kill them. I still need some early-instar pics as well as some showing spotted lanternflies being consumed by parasites and fungi.

Adult showing colorful underwings. Presumably to advertise toxicity to predators. Binky Lee Preserve, Chester Springs, PA.
Gravid female. John Heinz National Wildlife Refuge, Tinicum, PA.
Egg mass on a tree. The surface is a waxy substance that covers several rows of eggs. John Heinz National Wildlife Refuge, Tinicum, PA.
Third-instar nymph. Goshen Trail, Newtown Square, PA.
Three adults on a tree. Trees can have thousands. Binky Lee Preserve, Chester Springs, PA.
Sap oozing from feeding site wound. Ailanthus tree. Rose Tree Park, Media, PA.
Slick at base of Ailanthus tree caused by dripping honeydew (sugary excrement). Rose Tree Park, Media, PA.
Adult caught in spider web. Hildacy Preserve, Media, PA.

Below is a map showing the distribution of spotted lanternflies in North America as of October 3rd, 2019. Here’s a current map. To add a sighting, please sign up for iNaturalist (free) and post a photograph.

Here’s what the distribution is likely to be in the future (per Wakie et al. 2019):

Bag of water hanging from ceiling

15 mosquito-control strategies and devices that don’t work

Health officials love to remind people to use DEET and other CDC-approved repellents, but they tend to shy away from telling the public what doesn’t work. As a result, millions of people adopt ineffective techniques and gimmicky devices. These people are not only subjecting themselves to annoying mosquito bites, they are increasing the likelihood that family members will contract West Nile virus disease, Zika virus disease, eastern equine encephalitis, and other mosquito-borne diseases. So I thought I’d make a list of the top myths and scams just in case skeptical people are Googling.

1. Mosquito-repelling plants

Despite the claims of thousands of posts on Facebook and Pinterest, there are no plants that, when planted around your yard, repel mosquitoes. And, just to be clear, the plant marketed as “mosquito plant” does not repel mosquitoes. I know this is deeply upsetting news to many plant fans. I’m just the messenger.

2. Ultrasonic devices and apps

None of these have been found to work (details). It’s too bad. It would be really cool if they did. The FTC has taken some companies to court. There is, however, a device called The Mosquito that is effective at repelling teenagers.

3. Bags of water suspended from ceiling

This belief is common in Mexico, Central America, Spain, and certain pockets in the U.S. south. It’s a variation of the equally-ineffective tradition of hanging bags of water to repel house flies. Some people insist that you have to add coins (and just the right number).

4. Listerine

Nope — even when mixed with other ingredients like beer and epsom salts, spraying Listerine around your yard won’t repel mosquitoes. Just another internet rumor started by somebody with too much free time.

5. Citronella candles

Citronella candles only seem to work if you surround yourself with a lot of them, ideally in a protected area so that wind doesn’t dissipate the smoke. Similarly, Tiki torches that burn citronella-laced oil are ineffective. They smell great, though. The pleasant smell most likely contributes to the strong placebo effect. People absolutely believe they work even though they do not.

6. Bounce dryer sheets

Per one study fungus gnats (which don’t bite) were mildly repelled by dryer sheets. I’d wager these sheets might actually be attractive to mosquitoes (some species home in on perfumes).

7. Wrist bands with natural oils

At best, wrist bands will reduce the number of mosquito bites on your wrist simply because they can’t bite through the plastic. But they will not emit enough volatile compounds to shield the rest of you. NB: currently there are no wristbands that contain DEET or other CDC-approved repellent. Details.

8. Stickers laced with natural oils

Stickers only prevent mosquitoes from biting the flesh directly underneath the sticker. You’d need an awful lot of stickers for full protection. If you can rock that look, I say go for it. Note, same conclusion for the stickers that claim to infuse your bloodstream with B1.

9. Garlic

Eating garlic does not deter mosquitoes. Just deters other people.

10. Vitamin B1, B6, or B12 pills or patches

Nope, nope, and nope. Details. More details.

11. Mozi-Q pills

Just another scam. Details.

12. Bug Zappers

These devices are adored by people because they make a satisfying crackle when an insect meets its end. Indeed, people who own these seem to delight in the attention these things get when friends come over in the evening. But if you dump all the carcasses on a table and sort them (good family fun), you’ll find that only a very small fraction of the victims will be mosquitoes. In one study, 0.22% were mosquitoes. Mostly you’ve just electrocuted thousands of small, defenseless moths and night-active beetles. That’s a lot of bad karma. More details.

13. Dynatraps

These don’t appear to work. I’ve tried two and can confirm. If you’re still on the fence read some of the many 1-star reviews on Amazon.

14. Tubes of yeast and sugar

Contraptions filled with yeast and sugar are really good at attracting and killing fruit flies, ants, and wasps. They will not control your mosquitoes.

15. Bats and birds

Sadly, it’s a myth that constructing a bat or bird hotel in your backyard will eliminate your mosquito problem. Bats and birds will certainly eat mosquitoes under some circumstances (e.g., when they are caged with nothing else) but under natural conditions they prefer to eat larger insects. You should still construct bird and bat houses, though. Details.

More information

If you have questions, email me.