Irritating Plant Allergies You Should Know About

Have you ever developed a mysterious rash after gardening? Do you suspect plant allergies or sensitivities?

In the past year I’ve had two experiences that made me think twice about rushing to pick up the hoe and start working in the yard.

It’s sad because there’s little I enjoy more than being outside among the plants and flowers, getting fresh air and exercise.

But last week after indulging in some heavy-duty garden clean-up, I developed an extremely itchy bump on my inner left wrist. It turned bright red and grew quickly, erupting with clear fluid. The next day I had a few more bumps.

Although the original blister is now healing others have popped up on my torso and are driving me crazy. I’ve gotten some hives, too.

The same series of unfortunate events happened to me last fall after cutting the grass and raking and blowing leaves, except that the rash started as an itchy bump on my leg.

It took the better part of a month for the rash to clear.

As a precaution this spring I wore long sleeves, pants, boots, and gloves. I didn’t think poison ivy had a chance against this armor. I was wrong. Or maybe it wasn’t poison ivy.

What plants in my yard could be the culprit? I started investigating. What I learned may help you avoid the same miserable fate.


These sturdy shrubs with tough, hairy leaves and dusty stems are prized not so much for the beauty of their flowers but for the spicy sweet scent.

Although they are advertised as deer-resistant, my two Korean spice viburnum (Viburnum carlesii) suffered deer damage. Stems had been bitten off and/or broken by the foragers.

So I decided to move the bushes to a safer locale. Unfortunately, I didn’t wear a long-sleeved shirt because I didn’t see any any poison ivy actively growing.

You might wonder why I suspected the viburnum bush. There are a couple of reasons.

A viburnum bud and leaves surrounding it. The leaves are covered with fine hairs.
Tiny hairs cover the leaves of viburnum.
Viburnum blooms are white or blush pink and release a sweet fragrance.

First, this plant was unique to last Tuesday’s lawn chores and the rash started on Wednesday.

Second, I had the exact same rash experience last fall when I was working in the same shrub beds.

This led me to an internet search for allergic reactions to viburnum. Of course I found out too late that this plant can cause skin irritation.

Seems those hairy leaves are actually leaves covered with teeny-tiny thorns. These can stick in your skin and cause irritation or contact dermatitis.

I concluded the viburnum was a valid suspect.

But not the only suspect.


euphorbia Glacier Blue has variegated blue-green foliage and Sulphur yellow flowers.

This plant is also one that I worked on last Tuesday.

Turns out euphorbia is a well-known (except to me apparently) skin irritant. It contains a milky white sap (latex) that contains toxins.

This sap is a survival adaptation for euphorbias, just as thorns are for the viburnum (and other thorny plants like roses and stinging nettles), helping repel animals that might graze on these plants.

Unfortunately it can also cause irritation to people who come in contact with the plant.

Looking back, I remember pulling dead leaves off my euphorbia. Did I wash my hands or scratch after removing gloves? Did I wear gloves? I honestly can’t remember.

Another Google search informed me that the euphorbia family is huge and different species vary in the amount of toxins in their sap. Some have even been known to cause blindness if a person gets enough in their eye.

Winter damage on the euphorbia plant results in many brown leaves on this otherwise blue-green variegated plant.

My euphorbia is E.characias ‘Glacier Blue.’ Its plant profile warns that its sap is toxic. Was this the plant that caused my rash?

Seems like another good suspect.

Black-eyed Susan (Rudbeckia hirta)

black-eyed Susan blooms gold in the foreground of a deep blue lakeshore.

I cut down a stalk of Black-eyed Susan today and within a half an hour I felt a stinging on my neck.

Sure enough, I was developing a nice, itchy lump on my neck and could see a red mark where my skin was stinging.

A little “itch cream” got things under control.

But it reminded me that I’ve had this reaction before when pulling out or trimming these hardy, sunny flowers.

According to the National Capital Poison Center, Rudbeckia hirta is known to cause allergic reactions in people sensitive to it, including hives and asthma attacks.

Like viburnums, Black-eyed Susans are covered with tiny spiky hairs. Ouch.

Poison Ivy

Poison ivy rash is a common plant allergy. Look for plants with sets of 3 leaves.

And then there was one: yup, good ol’ poison ivy.

It grows rampantly in the wooded areas of both locations where I had been gardening. I thought I was safe from it because I wore long pants and shirts when near these areas. And I didn’t see any poison ivy so early in the spring.

Problem is, the urushiol in poison ivy that causes irritation is found not only in the leaves of the plant, but also in its stems, roots, berries, and flowers. And urushiol can stay on clothing, shoes, and garden tools for years unless and until it is cleaned off.

I was digging daffodils up in the woods, pulling apart bulbs and potting them for transplant.

Could I have dug up poison ivy roots, touched them with my gloves, and got the urushiol on my skin?

Poison ivy leaves grow in clusters of three. Leaves are shiny when new but dull over time.

Seems extremely likely. And I wore those gloves again without washing them.

Plus I noticed poison ivy sprouting in the lawn just yesterday.

That means the soles of my garden boots have a good chance of being contaminated.

Extreme Exposure

Well I now had a list of suspects each as likely as the next to be the guilty party.

It doesn’t matter all that much which plant it was because I learned I need to be careful around all of these plants.

You do, too.

Even if you aren’t allergic today you can develop an allergy at any time. Plus repeated exposures lead to greater sensitivity.

I didn’t have my first poison ivy rash until I was in my forties.

What Deer Already Know about Plant Allergies

A pattern that’s emerging as I investigate irritating plants is that all of these are advertised as deer-resistant.

It’s one reason I chose them to begin with.

Does this mean that gardening is futile in my neighborhood?

I’m not ready to give up, but I am dedicated to learning more before I plant and to practice good gardening habits.

Good Habits

Here are the habits I am pledging to follow from now on because I really don’t want to go through this discomfort again, but I do want to continue gardening.

  • Clean garden tools after each use and wash gloves regularly. I’m investing in two leather pairs so that I can alternate them. I’ve found that soft leather gloves can be washed and air-dried successfully. And leather offers the best fit and protection.
  • Remove garden boots or shoes carefully. I also wash these regularly.
  • Wear protective clothing and socks when working around plants and use care when removing this clothing. Wash immediately rather than placing in a hamper or basket (or leaving clothes on the floor!)
  • Wear protective eyewear when pruning or removing suspect plants, especially euphorbia.
  • Wash hands and arms with soap and water immediately after gardening.
  • Avoid using “vacuum” (bagging) features on mowers or leaf blowers as this can lead to being sprayed with and inhaling toxins from mulched plant parts.

I hope my experience helps you to avoid your own misfortunes in the garden and recognize plant allergies and sensitivities.

Gardening is such a relaxing and satisfying hobby that it is a shame when something so simple ruins the experience.

Be careful. It’s a jungle out there.

Copyright 2023 All rights reserved. See Legalese page for permissions.

This post was updated on May 07, 2024.

Author: A. JoAnn

Here is where I share the beauty I find in everyday life; and the humor, too!