What’s Eating Your Petunias?

Originally posted July 2012
golden mantel ground squirrel eating petuniasGolden-Mantled Ground Squirrel at Seven Falls in Manitou Springs, Colorado Photo by Cindy Pierce June 2012

The above photo is by far one of my favorites of all time. I took it a few weeks ago while vacationing in Colorado. My boyfriend and I broke away from the rest of the extended family and took my mom on a special day of local excursions in the southern area of Colorado. Along with the famous Pike’s Peak Cog Railway, we also visited Seven Falls – a beautiful canyon area in Manitou Springs that boasts a tall, seven-level waterfall. There are several ways you can view the seven-level waterfall – from the ground, from a viewing platform a few stories high, and from the top of the canyon via a steep and lengthy, zig-zag staircase. You can also view the falls at night when they are lighted with many colors.

While my boyfriend and I took the quick elevator ride up to the mid-level viewing platform, my mom decided to hang out at the base. Along the creek and pathways of the park hung large double hanging baskets of beautiful, healthy red, white and purple petunias. My mom appeared to be intently admiring these flower baskets as my boyfriend and I tried to get her attention from the viewing platform for a photo op. No luck.

When we arrived back down at base, my mom began laughing and telling us how a ground squirrel was sprawled in the middle of one of the petunia baskets, eating away at the flowers. I thought it must’ve been a funny sight and wondered just how the petunias stayed so abundant with the number of ground squirrels around. As my boyfriend decided to take the trek up to the top of the falls, my mom and I sat on a park bench, watched the Native American dancers and simply took in the scenery. We watched the rainbow trout swim in the nearby pond and the chipmunks and ground squirrels dart around and scoop up crumbs of dropped tourist food. Suddenly, I saw a rather large ground squirrel appear in the center of one of the petunia baskets right next to us. Camera in hand, I snapped several photos as the critter rapidly tore off petunia blooms one at a time and stuffed them in its mouth. She was absolutely adorable (if you look closely at the photo, “she” appears to have nursing babies).

I’m sure the maintenance crews at Seven Falls probably don’t find the squirrels quite as adorable as we did. I’m sure they are tasked with replacing the flowers in the baskets quite often. But, then again, perhaps the squirrels provide a natural deadheading and trimming service, enabling the plant to regenerate? *More on this later . . .

squirrel #2

Witnessing how rapid this one little squirrel devoured multiple blooms, it reminded me of how quickly a newly planted bed of petunias can disappear from our yards at home. From my research, it appears that whitetail deer, rabbits, and all types of rodents (including squirrels) enjoy the taste of petunias. The vibrantly colored blooms are like neon signs beckoning these mammals to come over and partake of them. Whilst this was funny for me to witness, I’m sure other people don’t find it as funny. Rodents can be irritating, especially when they’re ruining your gardening. If they become familiar with your garden for sources of food, they may be spending more time on your property, potentially finding ways to enter your home. Squirrels can get through small gaps, allowing them access into your home to nest. If this happens, it’s important to call out a pest company that offers the humane removal of squirrels. This should get rid of the rodents carefully, ensuring that they’re safe. It will also protect your plants.

However, it’s not just animals, insects seem to very much enjoy petunias as well, especially worms and most especially, the tobacco hornworm. Petunias are of the Solanaceae family, commonly known as the nightshade family. The nightshade family is a large family of flowering plants; their flowers being tubular or semi-tubular, with some flower varieties having fused petals. If you look closely at a petunia’s bloom, you will see the margins of its fused petals.

The nightshade family consists of both very popular edible plants and in contrast, very toxic plants – some fatally toxic, such as belladonna. Among the important agricultural plants of the nightshade family are tomatoes, peppers, eggplant and potatoes. I find it quite ironic that some of the most common vegetables we eat, perhaps on a daily basis (think tomatoes on hamburgers, in salsa, spaghetti sauce, ketchup, etc.) are found in the same classification as deadly belladonna.

However, speaking of the toxicity of nightshades, some of the plants in this family are toxic in high doses but are helpful and/or useful in smaller doses. For example, extracts of some of the plants of this family are used to curb the nausea of motion sickness and in chemotherapy patients. Also, the capsaicin extract of peppers is used in pepper spray – a personal safety device that sprays and temporarily stuns people and other mammals. Another interesting plant of the nightshade family is nicotiana or tobacco. I suppose the effect nicotine has on the body can certainly be described as drug-like or addictive when we consider the many different effects the varied nightshade plants have on the body. It has been determined it is the alkaloid compounds of nightshades that give the plant its helpful and/or harmful attributes.

Although there is no consensus among researchers, it is thought best for people suffering from nerve, muscle and/or joint conditions to limit or avoid food of the nightshade family due to the inflammatory effects alkaloids may have on these body functions. It is good to note here also, that if you have heard the old wives’ tale to avoid eating green potatoes, you may wish to take heed. While it is the chlorophyll in the potato that actually makes it green, the color also corresponds with a higher presence of alkaloids. Same with green tomatoes. If you have a form of arthritis, as do I, but absolutely love one or more of the nightshade veggies, it is good to note that cooking them reduces the amount of alkaloids by about 40 – 50%. So, cooked tomatoes are less “toxic” than those just out of the garden. I admit I still eat tomatoes in both manners, but I just don’t overdo it either way. As you know, there are very good compounds found in tomatoes too – such as Vitamin C and the antioxidant lycopene.

Well, back to petunias and what eats them. You may be able to guess that petunias fall into a benign branch of the nightshade family that is safe for mammals to eat versus one of the highly poisonous or deadly branches. While petunias do possess alkaloids like the rest of the nightshades, it does not possess the highly toxic form. And because the vibrant, sweet-tasting blooms of petunias are borne without thorns or thistles, critters find them irresistible and easy to eat. In addition to mammals devouring your petunias, as I mentioned earlier, some worms are especially attracted to nightshades as well. The tobacco hornworm (a very large, bright green worm) that you can guess – loves the nightshade plant, tobacco – really isn’t all that discerning when tobacco isn’t around. This worm will attack any nightshade plant, including your tomato, pepper and potato plants. Of course, it likes petunias as well!

tobacco hornworm

Tobacco Hornworm courtesy of http://coopext.colostate.edu/4dmg/Pests/tomato.htm

An interesting side note is Morning Glory and Moonflower Vine were once considered a part of the nightshade family in the past, but their family has been changed, of late, to Convolvulaceae. If you go one classification step up, however, they remain in the same Order as nightshades and have some of the same flower and alkaloid characteristics. The reason I bring this up is because their flowers are very similar to Petunias in shape and size and you’ll see the tobacco hornworm likes feasting on the leaves of these vines as well. In addition, if you have both moonflowers and petunias in your landscape, the large, hummingbird-sized parent moths of these worms (Sphinx Moths) will visit both flowers equally!

So, just what can you do to keep your petunias full and healthy, or at least alive, this season? With regard to mammals like the cute little critter in the photo at the top of my blog post, ironically, the use of another nightshade plant may be the best solution!

Spraying diluted hot pepper juice or sprinkling hot pepper flakes around your ornamentals and vegetables may help dissuade these critters’ palates. I would administer the pepper spray in the late evening hours so the sun does not intensify the solution, however. About the tobacco hornworm? The pepper juice spray might help, but then again sometimes the hornworm actually eats green peppers so simply removing the gargantuan worms by hand (ugh) may be the best way to control them. While I don’t like to handle insects by hand, I still find them fascinating and would never purposely kill them (yellow jackets are an exception, btw!).

Personally, I love the mature moths that the hornworms develop into and simply find the larvae don’t do that much damage to my ornamentals and therefore I do not do anything to specifically deter them from my yard. I often see their droppings but resign myself to knowing I’ll have more moths to admire in late summer/early fall. (Yes, these worms are big enough to have droppings to see and in fact, this is one way to locate them on your plants. For as big as they are – they are incredibly hard to see as they excellently blend with the greenery.) If you have kiddos or are a curious adult, click http://www.birds-n-garden.com/white-lined_sphinx_hummingbird_moths.html to see how to raise the tobacco hornworms you pick off your plants and transform them into gorgeous, iridescent, hummingbird-sized Sphinx Moths.

*Keep in mind, if your efforts to reduce damage to your petunias by animals or insects are less than successful, do not fret if you still have roots and stems intact. Oftentimes, with a little pampering, you may be able to bring forth a stronger plant as petunias are known to bounce back more fully when trimmed and deadheaded.

Taking into consideration:

– overindulging in edible nightshades may aggravate illness, but eliminating them entirely will cause you to miss out on vitamins and antioxidants;

– overindulgence of some compounds of nightshades may kill you, while small quantities may indeed heal you; and,

– aggressively ridding every pest from your nightshades may burn them (pepper juice) or cause leggy overgrowth, allowing a few pests to “trim” the plants may actually promote regeneration;

I’d like to end this post today by saying I believe we can view the contrasting properties of the fascinating plants of the nightshade family as a perfect justification of the age-old adage, Moderation in All Things . . .

Until next time,



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