Missed Part 1? Read it here.
One of the more popular things I have ever written (for another website as it were) was an article on invasive garden plants. It has been viewed almost 200,000 times. At the end of the article, I asked readers to share their experiences with aggressive plants. Readers left almost 500 comments! It seems that many people have had a plant that has run wild through their yard. Gardeners welcomed a chance to share their frustrations and struggles in the comment section of the article.
But as well as sharing their problems, a few readers took exception with one of the plants that I had deemed problematic: Lily-of-the-Valley.
"I would LOVE to have Lily-of-the-Valley take over my space. They have a sweet, delicate smell." wrote Lois Gibbs of Buzzards Bay, MA
Ah, Lily-of-the-Valley! Yes, the white bell-shaped flowers are cute and their fragrance is divine, but boy can it spread. Here's Lily-of-the-Valley's secret underground weapon:
Just look at those roots! They run deep and shoot out in different directions (I actually missed some of the deepest part of the root when I dug this plant out). Unless you dig down deep and wide with your shovel, you are very likely to miss a segment of the plant's prolific root system.
Just when you sit back and relax thinking the issue is dealt with, new Lily-of-the-Valley pops up to mock your efforts.
Not only does Lily-of-the-Valley spread unseen under the ground, it developes little orange-colored berries that are filled with seed.
And while I am grumbling about issues with this plant, I'll also mention that Lily-of-the-Valley is very susceptible to fungal leaf spot in the late summer.
Some of my readers did not appreciate it when I expressed a need for caution when it came to planting aggressive plants:
"OK ladies...this article and all your comments were all very helpful...however...any "bloomin' idiot flowers" you'd like to get rid of just send them "crazy" growers to me!" Jan B. Crossville, TN
"I am glad you posted this, I need some aggressive plants up here..." Debby Boyle, Necedah, WI
"Funny. Everyone is trying to get rid of invasive plants and I am trying to find them. I am in Dallas, TX and it's so hot and dry...I need something for my pitiful yard..." SkyN, Texas
I will reply here as I did in the original article. Be careful what you wish for! With all due respect, what these people are really looking for is not an invasive plant, but one that will be successful in a challenging outdoor area. Yes, they may face some difficult growing conditions, but that isn't a good reason for resorting to a plant that is as problematic as it is pretty. It's so much better to take a step back and look for a plant that is appropriate to the site.
I am not going so far as to say never plant Lily-of-the-Valley. Just do it cautiously knowing you are planting something that can really spread. Choose your spot carefully, so hopefully it can be contained.
I found Lily-of-the-Valley growing in my garden when we moved in. Under a big maple at the back of the yard, it's limited to an island bed and hasn't been a problem... so far. In the shadow of the maple, it fights periwinkle and English Ivy for turf. In the front garden however, Lily-of-the-Valley is a real nuisance. I've tried to get rid of it, but man is it difficult!
A shade gardener who is not afraid of Creeping Jenny.
Groundcovers
The majority of readers wanted to weigh-in on plants that were giving them grief. Groundcovers were high on the list of problem plants. Here's a list of the ones mentioned most frequently:
• Creeping Jenny, Lysimachia nummularia
• Goutweed, Aegopodium podagraria 'variegatum'
• Periwinkle, Vinca minor
• False Lamium, Lamium galeobdolon 'Florentinum'
• Bugleweed, Ajuga
• Lily-of-the-Valley, Convallaria majalis
• Winter Creeper, Euonymus fortunei
• Chameleon Plant, Houttunynia cordata
"Chameleon Plant– beautiful, but it spreads like crazy and I can't get rid of it. It's those underground runners. NEVER, NEVER PLANT THIS." Diane D. Lawrenceville, GA
"Creeping Charlie is much worse than Creeping Jenny and I am not just saying that because I am a woman.", E. Simmons, Florence AZ
Suggestions and Alternatives
As I wrote in the previous post, gardeners can on occasion be too impatient when it comes to filling up their flowerbeds. Patience is a virtue, especially when it comes to gardening. It is better to look for plants that are"clump-forming" and fill a space with a larger number of plants clustered together.
Chinese Lanterns, Physalis alkekengi
Gooseneck Loosestrife, Lysimachia clethroides on the lower right.
Rose of Sharon (left) and Obedient Plant (right)
There were lots of other plants that were called out for not being well-behaved. Here are just a few that readers complained about:
• Japanese Knotweed, Fallopia japonica
• Anemone Canadensis
• Chinese Lanterns, Physalis alkekengi
• Spiderwort, Tradescantia
• Obedient Plant, Physostegia virginiana
• Gooseneck Loosestrife, Lysimachia clethroides
• Bamboo, Bambusoideae (spreads underground)
• St. John's Wort, Hypericum perforatum
• Purple Heart, Wandering Jew Purpurea
• Ribbon Grass, Phalaris arundinacea
• Sundrops, Evening Primrose, Oenothera
• Mexican Evening Primrose, Oenothera speciosa
• Snow-on-the-Mountain, Aegopodium podagraria
• Rose of Sharon, Althea (a terrible self-seeder, but it has to be said that it is a good, late-summer shrub. Look for one of the varieties that are sterile, if you are concerned.)
• Orange Daylilies, hermerocallis fulva (not the hybrid daylilies, but the kind you see growing in ditches and at the side of the road)
"I have Yarrow that has taken over my front lawn..." Kris Lee, Jackson, WY
Another problem is Purple Heart, Wandering Jew Purpurea. It came with the house when we bought it. It is everywhere. I have removed bags of it and every year it comes back. I have grown to detest it...", Burrgmb, Southlake Texas
"Tree of Heaven is the worst name for a pest that I can think of!", Kristen McCann, Fresno CA
"Snow-on-the-Mountain and Yucca are both my garden nemesis. Here in Michigan they grow like CRAZY! Catnip is another that I will always avoid." J Merillant, Michigan, MI
"Another aggressive plant is Mexican Morning Primrose. It is a really pretty pink groundcover. However it developes a very intricate, dense underground network of roots that are a real problem to eradicate..." Gerald K, Mather, CA
Suggestions and Alternatives
There are so many great perennials! There is no need to feel that you have to resort to an unstoppable plant just to find something that works. If you are stuck on what will grow in a difficult area, do some homework. Look for books on shade, clay soil, dry or otherwise inhospitable conditions. See if there is a garden tour or open gardens in your area and find inspiration there.
There is a great plant for almost any situation– even the difficult ones!
I have Anemone Canadensis in an isolated bed, so for me it hasn't been a problem. Others really dislike its spreading ways. On the right is Snow-on-the-Mountain.
Wisteria (top), Trumpet Vine (lower left) and Virginia Creeper (lower right)
Vines and Climbers:
So many different types of vines have given gardeners concern. Trumpet Vine and Asian Wisteria were amongst the most-hated vines, but the others mentioned most frequently were:
• Honeysuckle, Lonicera (native to Korea, China and Japan)
• English Ivy, Hedera helix
• Virginia Creeper, Parthenocissus quinquefolia
"Morning Glories* are a nightmare. One plant had taken over and I find myself constantly trying to pull them out as they reappear. Ugh...." Mary Kay@Studio23 Thirty
*Morning Glories are great self-seeders and can become a problem given the right conditions. If you have white flowers on Morning Glory-like foliage, you actually have Bindweed.
Suggestions and Alternatives
Most Clematis are a great choice for full sun (Sweet Autumn Clematis might be one of the exceptions). Climbing roses on a support are another choice for sun (or in some cases for part-shade. Rambling roses will often scramble up a tree for instance).
If you want to grow Wisteria, I have heard that the North American native, Wisteria frutescens is a much better choice than Asian Wisteria.
For shade you can always try a Climbing Hydrangea, Hydrangea petiolaris. It is a vine that is a little slow to get established, but isn't invasive to my knowledge.
A large patch of Oregano in the left foreground and Chives on the right.
Herbs:
"Mint!!! I made the mistake of planting it in my flowerbeds, as they told me it was a natural ant repellent at the garden centre. Yeah right! Not only has it helped, it has taken over my bed..." Ldavis49, Knoxville, TN
• Mint, Mentha
• Oregano, Origanum vulgare
• Lemon Balm, Melissa officinalis
• Sweet Woodruff, Galium odoratum
• Chamomile, Matricaria maritima (great self-seeder)
• Feverfew, Tanacetum parthenium (great self-seeder)
• Chives, Allium schoenoprasum (great self-seeder)
• Thyme, Thymus (given ideal conditions)
• Tansy, Tanacetum vulgare
• Comfrey, Symphytum officinale
• Bee Balm, Monarda (makes some lists. I have it in my garden and find it is fairly easy to remove)
• Pennyroyal, Mentha pulegium (member of the mint family)
Suggestions and Alternatives
The solution for herbs that spread a little too vigorously is simple: plant them in a container.
Cut chives back hard after they flower. You'll have fresh growth in a couple of weeks and will eliminate the possibility of unwanted seedlings.
Some gardeners, myself included, like herbs like Feverfew despite the fact that it reseeds itself a bit too readily. If you dislike prolific self-seeders, cut off the spent flowers before they set seed. Another way to limit the number of new seedlings is to remove most of the plants after they've finished flowering and leave only a few to reseed.
If you have any problems with plants, please share your experiences in the comment section of this post. Suggestions or alternatives to invasive plants are also most welcome!
