I found a new “favorite” plant last summer. It’s called Dalechampia dioscorefolia, otherwise known as the Costa Rican Butterfly Vine. Its stunningly beautiful, exotic flowers were unlike those on any of the vines I typically see at nurseries and easily earned a place in my disorganized (and experimental) backyard garden.
Given its unique beauty, I placed it on a trellis directly outside my bedroom window so I could see it every day and observe its progress. After a few months of growth, it was still quite floppy and had not wrapped itself around places high enough on the trellis for my liking.
So one Saturday, I went out and wrestled apart many of the branches of the vine that had wrapped around themselves and set them up to reach over the trellis. After about half an hour’s worth of untangling, I had a sense that the plant was quite literally moving in the right direction.
I also noticed that my arms were a bit itchy.
A LITTLE SURPRISE
I went inside to wash up to my elbows with soap, believing it would take care of any skin irritation.
By the next morning, however, I was laughing at myself for having been so clueless. Both my arms and my midriff (the part that wasn’t completely covered by my T-shirt) were covered in a rash that looked something like poison oak. Two doctor friends both looked at the rash and, after exclaiming “eeww” and making faces you don’t want to see doctors make, concluded knowingly that the plant I had grappled with must have possessed some irritating properties.
I immediately went to my garden guide to look up the vine and see if I had missed something in its description. Interestingly, there was absolutely no mention of any toxicity or potential irritation. Not being satisfied, I took the further step of looking up the plant’s family name: Euphorbiaceae. I’m reasonably familiar with Euphorbias, so I was a bit surprised to see that the sap is irritating or poisonous in many species – including, apparently, that of the Costa Rican Butterfly Vine.
I was quick to point out the properties of this plant to the nursery that sold it to me, suggesting that other clients might want to know that the vine has skin-irritating sap. Certainly I didn’t want anyone else to go through what I was going through already.
I don’t want to over-dramatize the situation. The irritation wasn’t horrible, and I was able to control the itching with homeopathic products that helped me through the three weeks I had the rash with minimal discomfort – other than the occasional embarrassment of having what looked like the plague all over my arms.
Nonetheless, my brush with this plant’s toxins reminded me of a lesson I ought to have learned long ago. True, we can’t do enough homework and research to prevent every such situation from arising, but there definitely are some steps we can all take to be sure our clients are protected from hazardous plants.
For starters, it’s always important to research a new plant in garden guides. In the popular Sunset Western Garden Book, for example, the legend that accompanies each plant description raises a warning for plants known to be poisonous or irritating. But no such guide is foolproof, because people react differently to different substances they encounter in their environments. That’s why it’s good practice to ask clients about allergies or sensitivities as you begin creating a planting plan.
I’m not suggesting that you mount a major research effort every time you select plants. But if you’re in a situation where you know your client has sensitivities to pollen or a general problem with allergies, there are a couple of simple things you can do to be on the safe side.
First, don’t be satisfied (as I was in the case of my vine) with information from a single source. If you’ve relied on a garden guide, for instance, it’s a good idea to verify that information with staff at your local nursery or garden center or track information down via the Internet. And don’t be entirely satisfied if you don’t find a specific warning: Look up the family name of the plant and check the whole lot of them out for potential toxicity.
You’re not always going to be able to prevent problems with every plant (again, different people are sensitive to different things), but the more research you do, the better are your chances of avoiding the nastier consequences of making a mistake.
And this isn’t just about homeowners with allergies: I now make it a habit to include children and any household pets in my design and decision-making processes and use special care in steering clear of potentially toxic plants. Better to err on the side of caution when it’s not your own yard!
Trouble is that irritating, toxic or potentially toxic plants are all around us. The list below is hardly exhaustive, but it is impressive both in length and in the familiarity of many of the plants – and for the fact that it’s just about southern California. I can only imagine that a national guidebook on this topic would run on for many hundreds of pages!
[ ] Aconitum (Monkshood). This unusual and beautiful perennial is quite poisonous if ingested. Use it only in gardens where there is absolutely no chance of children or pets chomping on its flowers or leaves.
[ ] Alocasia and Colocasia (Elephant’s Ear/Taro). All parts of these plants can be poisonous if ingested, and exposure to the sap can cause skin irritation. Plant this in the background, where it will not be easily brushed – or eaten by a pet.
[ ] Anemone. All parts of this shade-loving (and therefore extremely useful) perennial are poisonous if ingested.
[ ] Brugmansia (Angel’s Trumpet). All parts are poisonous if ingested, and I’ve been told that its effects are hallucinogenic – something of which I have no firsthand knowledge! I use this plant frequently to exploit its large, trumpet-shaped flowers. When I do, I always inform my clients of its toxic properties as a precaution.
[ ] Brunfelsia (Yesterday, Today and Tomorrow). All parts of this shrub are poisonous if ingested. This is another plant I use frequently, in this case to take advantage of its fragrance and flowers and the fact that it thrives in partial shade.
[ ] Cestrum. This shrub’s fruit and sap are both poisonous if ingested – and tough to avoid because they’re so widely used. Night Blooming Jasmine, for example, is part of this genus.
[ ] Daphne. All parts of this plant are poisonous if ingested – especially the fruits. The most commonly used variety of this shrub in my area is Daphne odora, prized and widely used because of its fragrance and adaptability.
[ ] Digitalis (Foxglove). All parts are poisonous if ingested. The powerful heart drug digitalis is derived from this plant, which says it all. I use this in many designs, and I always mention this plant’s name to clients and wait for recognition. Whether they’re aware of its specific properties or not, I always voice the caution.
[ ] Erythrina (Coral Tree). The seeds of this majestic tree are poisonous if ingested. Trouble is, the deep coral-colored seed pods are so vibrant that they attract lots of attention – a particular problem with small children. When I use them, I am liberal with warnings.
[ ] Euphorbias. As I’ve just discovered for myself, the sap of these plants is irritating or poisonous in many species. Unfortunately, it’s a huge genus (including such well-known shrubs as Poinsettias) and is therefore hard to avoid. Special care should be used in moving or handling them.
[ ] Gelsemium sempervirens (Carolina Jessamine). All parts of this vine, popular for its vigor and bright yellow flowers, are poisonous if ingested. This is another plant to keep away from children and pets.
[ ] Heliotropium arborescens (Heliotrope). All parts of this perennial are poisonous if ingested. I like to use this plant, which grows to about two feet tall and works well in the middle of borders, and love its deep-purple flower clusters. So far, I haven’t run into problems in using it, but I’m always watching.
[ ] Helleborus. All parts of this shade-loving perennial are poisonous if ingested.
[ ] Nerium oleander (Oleander). All parts of this widely used plant are poisonous if ingested, which seems to be something a lot of my clients know without my having to tell them. Deer are wise to its toxicity as well, making it an effective barrier plant. The one point I make with clients is not to use the wood as barbecue kindling: When oleander burns, it gives off toxic fumes.
[ ] Nicotiana. All parts of this plant, sold in southern California as an annual, are extremely poisonous if ingested. Many people prize it for its hardiness, but I tend to avoid it because of the “extreme” caution and because there are so many other options when it comes to plants for borders.
[ ] Rhododendron (includes Azaleas). The leaves of these plants – staples of the American garden – are toxic if ingested. It’s the hardiest shade shrub I use, and I will continue to do so because I’ve never heard of any incidents or problems having to do with toxicity.
[ ] Schinus molle (California Pepper). Direct contact with the foliage can cause dermatitis, but it’s not much of a threat in that respect (at least by comparison to perennials and shrubs) because the leaves are typically out of reach of the average garden visitor.
[ ] Solanum (includes Potato Vines). Most of these plants – which in my book get too woody to be useful – are poisonous when ingested. Frankly, I wasn’t aware of this toxicity until recently, and I’m happy to have yet another reason not to use them.
[ ] Spartium junceum (Spanish Broom). All parts of this rangy shrub are poisonous if ingested. It’s intensely fragrant yellow flowers make it useful (with the appropriate caveats, of course).
POINTS OF CARE
All of these plants (even the ones I personally don’t like) are too useful in gardens to be dismissed out of hand. It’s simply a matter of deciding on appropriate uses in given settings and of warning your clients about potential hazards.
In my conversations on the subject, I point out that heat may increase the irritation caused by some of these plants. I also suggest, when clients want the plants despite my warnings, that they invest in good leather or goatskin gloves and wear long sleeves and long pants while working near or with these plants.
I further advise care in using these plants as a source for cut flowers. Visitors may want to touch a beautiful arrangement without being aware of the nature of the plants in the vase. Remember: Mother Nature created these stunning flowers and unusual plants to attract – and that includes us!
With watershapes in particular, I spread caution with great care: Placing any potentially toxic plants near a pond or stream will endanger wildlife both in and around the watershape, possibly poisoning fish and any water-loving creature that might eat them. Even the water itself might become poisonous.
As is the case with a range of other design considerations, I work with my clients, listen to their requests and give them appropriate feedback, including warnings where they are warranted. As I mentioned above, I prefer to be overly cautious by way of protecting myself and my business by disclosing any hazards a plant may present.
Stephanie Rose wrote her Natural Companions column for WaterShapes for eight years and also served as editor of LandShapes magazine. She may be reached at [email protected]