In the world of professional horticulture, we are perennially teaching people to put the right plant in the right place. “I’m sorry, but that just isn’t going to be happy in our heavy clay soils,” is a phrase that plays like a broken record around here, and it can certainly be discouraging to folks who aspire to that fabled green thumb when it comes to finding plants that love making a home in your garden. The irony is that some things that do well for someone else may inexplicably snub me, and vice versa. For example, I am pea green with envy that Jim Kincannon has a lovely stand of native Prairie Dropseed (Sporobolus heterolepis) in the IMA’s Rain Garden, which dipped a toe into my home garden soil and said, “Poo!” It’s hard to not take it personally, but instead of moping, I simply squared my shoulders and recruited Little Bluestem BLUE HEAVENTM (Schizachyrium scoparium ‘MinnBlueA’) to join Team Schneider. Success! If you ask me why one succeeded and the other didn’t, I won’t have an answer for you; they have almost identical cultural requirements for light, moisture and soil type, and both are Indiana natives.
When it comes to recommending “tried and true” plants, you can see why it can be difficult to give trustworthy advice. My advice? To be a successful gardener requires thick skin and a penchant for experimentation. Did I mention thick skin? This is not to excuse poor behavior; if you plant something in the perfect spot and then deprive it of a basic need (i.e. water), it won’t be the plant’s fault if it doesn’t do well. I suppose if the experiment is to see just how little work you can get away with, go for it, but I would suggest planning a giant increase in your plant budget to accommodate the yawning gaps that will dot your landscape. As a word to the wise, a plant labeled as “drought tolerant” does not necessarily mean it never needs water (remember the basics – all plants need some spectrum of light, moisture and nutrients). Establish plants first to give them the best chance to face adversity with a healthy root system. Then, if a plant decides not to commit, with a clear conscience you can honestly accept when it says, “I’m so sorry…it’s not you, it’s me.”
So it is with some hesitation that I share my list of favorite successful plants from my home garden. After all, you may have tried these already and found them to be utter failures, which would be such a shame, because in my garden at home they look GREAT! What I can give you are the parameters of my growing conditions: I started with acceptable clay soils and have added a fair amount of organic matter for the past three years (leaf compost and mulch). My home was built in the 1920s, so while my soils are not compacted from new construction, I still wanted to add the organics to allow for better water and oxygen penetration to the roots. Drainage is moderate in most areas with a few spots that stay more saturated from heavier clay content. I never use synthetic fertilizers on anything planted in-ground, and while I give plants consistent water the first year they are planted, I am a bit more lax on watering things that have been established unless we are under severe drought conditions like this past summer. The plants on my current recommended list are ones from my home garden that have survived at least two winters in my clay soils with little to no extra coddling during the growing season.
Agastache ‘Heatwave’ – This one was an experiment that turned out to be a pleasant surprise for me; I anticipated my soils would be too heavy for winter survival, but it has made a glorious return after the past two winters. A hybrid from seed, this giant hyssop has gorgeous, long-lasting flowers of magenta that do not fade as they age. I had a couple hummingbirds that would visit this plant morning and evening, and the bees just can’t leave it alone. This is one of my favorites for late summer/early fall color, and it’s quite large…it has consistently been at least five feet tall! I have it planted in full sun, and give it no extra water or care.
Anchusa azurea ‘Dropmore’ – Again, a surprise success plant, and one that was previously completely foreign to me; I confess I ordered it because of the pretty picture in the Bluestone catalog. The first year it just sat there, not doing a whole lot. The following season it did not bloom, but had sizeable rosettes of fuzzy leaves that provided a textural element where it was sited. This year it blew me away with giant flower stalks (six to seven feet tall at peak flower) that provided a riot of true blue flowers early in the season. It is probably too large for the space I have it in, but regardless the flowers are just too heavy to stand on their own. It’s not a plant you would put in a formal setting, but in my opinion, with proper support the unruliness is outweighed by that flower color. I actually let it flop over and pop up through my other perennials until it started to go to seed, then I cut the whole thing back to the ground and let it develop a nice clump of basal foliage for the remainder of the season. No extra water or care beyond cutting it back.
Buddleia ‘Miss Molly’ – My favorite butterfly bush because of the color and size, ‘Miss Molly’ has a rich, saturated flower of reddish-purple that doesn’t fade into the background like some of the other Buddleias. It’s also compact enough to fit perfectly into perennial plantings without overwhelming the surrounding plants. The blooms persist until frost, but I do occasionally deadhead when I remember to take the time. I only provided supplemental water during the most severe drought month this summer, but the plant has otherwise been on a low-water regimen.
Campanula ‘Pink Octopus’ – A cross between cultivars C. takesimana ‘Beautiful Trust’ and C. punctata ‘Pink Chimes,’ this bellflower is smothered in unique, pink flowers with thin, drooping petals that really do have a bizarre resemblance to the tentacles of an octopus. It also has a long bloom period, but even after the flowers have finished I simply love the beautiful foliage that makes a solid, weed-free ground cover. The original clump has slowly been expanding to the point where it could probably be divided, but it hasn’t been overly aggressive by any measure. ‘Pink Octopus’ is happily sited in a bed where my heaviest clay is, which makes sense; Campanulas tend to be good candidates for heavy soils that remain moist. I did provide a bit of supplemental water during the drought to give it one good watering a week, but I never saw any signs of drought stress on this plant. It reaches ten to fifteen inches tall with the flowers, making it a good choice for the front of the border.
Eremurus ‘Cleopatra’ – I bought this three years ago, unsure of how long-lived it would be in my soils. To my delight it has returned faithfully each spring and is the plant that brings me the most joy, though the length of show is quite short. Ever since my internship at Olbrich Botanical Gardens in 2006 when I was introduced to this plant, I have wanted it for my own; those towering flower stalks hold themselves so regally above the surrounding early summer garden. The first year I planted it there was one lonely little flower. The foliage disappears for dormancy in the heat of summer, so I completely forgot that I had even purchased one by fall when I planted an upright juniper close to the same spot. The following spring I was curious to note what looked like daffodil foliage emerging at the foot of the juniper…I KNEW I hadn’t planted any daffs there! It wasn’t until four flower stalks appeared that I realized my foxtail lily had survived (again, in my clay soils, no special soil amendments for drainage), and each year it has gotten better and more robust! My theory is that the root competition from the tree keeps the soil dry enough for overwintering. Even though this one makes only a couple weeks of show early in the season, I would not garden without it.
Kniphofia uvaria ‘Flamenco’ – I have three huge plants at home and have done absolutely nothing to encourage them, yet somehow they are thriving in my clay soil. I had over twenty blooms on a single plant this year, which give a similar drama to the garden as that of the Eremurus. The advantage with the Kniphofia is that the blooms are longer lasting and the strappy foliage is semi-evergreen, giving it more staying power for use as an architectural statement in garden designs. I think this would be a gorgeous plant in any garden. I dug up one plant last year to make room for the others and gave it to my neighbor who, bless his heart, is often unable to spend sufficient time in his garden. Even so, he really loves gardens and had admired that plant in particular in my yard, so while he’s killed most of the things I’ve given him so far, I decided to share. Guess what…that plant is performing for him the same way it did in my garden and put on a spectacular show this year! I did not give mine an ounce of supplemental water this year and they pulled through the drought with flying colors.
Lychnis coronaria ‘Atrosanguinea’ – The foliage color and texture of this plant provides great contrast among other perennials, and I actually like that it seeds around my garden; I simply pull it out where I don’t want it. Rose campion is very similar to lamb’s ear with fuzzy, silver foliage rosettes, but the flowers positively glow when they’re in full glory early to mid-summer. I have this plant sited where it gets morning shade and afternoon sun, but that magenta-pink flower is a standout in any light. It’s fairly tall with the flower stalk (two to three feet), but without the bloom the basal rosette itself only reaches a couple inches in height. Something to keep in mind is that it doesn’t flower at all the first year, which is why I appreciate the artistry of the foliage until the second season. No extra watering needed to keep this happy, it has also survived in clay soils through several winters on a slight rise (not really on a slope, just not in a low spot).
The following are plants that I really want to put on my favorites list, but they just haven’t been in my garden long enough for me to be sure.
Bouteloua gracilis ‘Blonde Ambition’ – I just planted this blue grama grass this spring, but I LOVE what it did for me! It created a translucent screening effect with the dancing, pale yellow (“blonde”) flowers that are held above the foliage from mid-summer well into fall. It got much larger than I had anticipated in one season (three feet with flowers), but it plays so well with other plants that I’m pleased I put it in front of everything else. I planted it in a raised bed to give it excellent drainage for the winter, but it has not been in the ground for even a full season so I cannot fully endorse it yet. I have high hopes for this one, not just as a summer-blooming grass, but for winter show as well. The seed heads supposedly persist through even heavy snow cover…we’ll just have to see!
Centranthus ruber ‘Coccineus’ – This red valerian is probably the longest continual blooming perennial in my garden. It took a year or so to get itself established, but this past season it came into its own and developed into a lovely mound of bright, pinky-red panicles. I have yet to notice any seedlings in my garden, but it has been known to self-sow if it’s particularly happy; I’ll be curious to see if it will seed around in years to come. My Centranthus has stayed a modest size for me (two to three feet), and has certainly met and exceeded my expectations for color and added contribution to the border. It is planted in my bed with heavier clay, and while it does tend to lean into other plants’ spaces I have not found it to be the smothering type. I did several cycles of selective dead-heading throughout the summer to promote better flowering, and I gave it some supplemental watering though the drought period, but I would still consider this an “easy” plant. Time will tell whether this becomes a favorite or a nuisance, but all indications thus far point to ‘fantastic!’
Penstemon ‘Dark Towers’ – Almost everything I’ve seen so far of this plant for beauty and durability has impressed me; the deep burgundy leaf color, gorgeous pink flowers in early summer on robust, upright stems, and the lovely seed heads that follow rival even the flowers and carry through the winter. At three feet tall it’s a perfect addition to plant mid-border. I’ve only had this for one full season in my home garden, but I’ve seen this planted in other places and have been hearing some worrisome whispers of rampant seeding that give me some hesitation to commit this to my recommended list. I haven’t given up hope yet…the unwanted seedlings are very easy to pull in a maintained garden space. We’ll just keep watch and make sure this beauty doesn’t become a beast.
Filed under: Horticulture