Michigan Regional
Lily Society

Companion Plants for Lilies,and Other Thoughts

By Donna J. Hathaway  - President, Pacific Northwest Lily Society

Originally published in the March 2001 NALS Quarterly Bulletin.  Modified by Dick Bayerl for posting on  the Michigan Regional Lily Society Web Site, with permission by Donna Hathaway

Introduction

As this is my first article for the quarterly, allow me to tell you a little about myself. I was raised in northern New England and moved to Portland, Oregon in 1977. I have always been an avid gardener, so when I discovered the plant paradise that is the Pacific Northwest I knew I would never go back. It took me awhile to discover lilies, because I thought all but Tiger lilies were tender tropicals that needed greenhouse conditions.  I attended my first lily show in 1987 and discovered that this was not so. That was all I needed to hear, and I have grown them ever since. I joined the regional in 1988 and our bulb sales have been the major source of my impoverishment. When I am not spending all my money on lilies it goes to roses, fragrant daffodils, and many unusual kinds of vegetable and flower seeds that I raise at home so I can have the exact varieties I want.

I also garden organically; so don't look here for any pesticide advice. I have found that mixed plantings go far in controlling common pests and diseases.  I don't pretend to be an expert at anything except my own little neck of the woods, but I hope others can benefit from my experience.

I have been the victim of bad companion planting more often than I care to admit.  Plants that would never be invasive in Vermont can be veritable pests where I now live due to our mild winters.  I have learned how to read between the lines of the major garden catalogs, because many of them are written for gardeners in the parts of the country that actually have winter. I hope my findings will be of use to those gardeners as well as in our corner of the country.

The first thing to know is don't ever pair lilies, or any bulbs or small perennials, with something with the words "ground cover" in its description. These plants are great for covering rough, dry, or difficult areas, but if given nice rich garden soil, they will take over and show no mercy.

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Here is my list of "best of the worst":

bulletPachysandra spp.
bulletExtremely invasive!
bulletEnglish ivy (Hedera helix).
bulletEven the variegated kinds will smother your bulbs.
bulletSweet Woodruff (Galium odoratum or Asperula odorata).
bulletInvasive and mat forming. Looks innocent but don't be fooled!
bulletSt. Johns Wort (Hypericum).
bulletVery invasive and smothering. Used medicinally to treat depression, but I get depressed just looking at what it can do to my garden. I inherited a patch of it and it takes no prisoners.
bulletLemon Balm (Melissa officinalis).
bulletInvasive and a prolific self seeder. I still can't believe nurseries charge money for this plant and its seeds. Sort of like buying dandelions.
bulletThe same goes for catnip: it is very pretty but it will spread quite rapidly, and neighborhood felines will roll around in it until everything in the vicinity, including your precious lilies, is smashed beyond recognition.
bulletThis is true even if you have a big patch of it elsewhere; they will always pick the plant near your lilies with Murphy's law precision.
bulletButtercup (Ranunculus repens).
bulletI had this once in a former garden. I thought: "how sweet, buttercups, just like the cow pastures back home." The next thing I knew they were everywhere, forming tight mats and harboring slugs.
bulletBamboo. All kinds.
bulletI don't care if they say they are "clump forming" as opposed to the running kind-don't believe it!  They must be segregated from all plants less aggressive than themselves, which is just about everything.
bulletIf you must have them, put them on an island in your pond or surround with concrete paving.  These will make your life miserable if they ever escape their bounds.
bulletThey do make a gorgeous backdrop for Oriental lilies if you can create an effective barrier.

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Another group of plants to be cautious with is other bulbs, believe it or not.

Here are a few suggestions:

bulletCommon Star-of-Bethlehem (Ornithogalum umbellatum).
bulletThis little bulb can stay under control in cold climates, but it can be a real pest in mild winter areas. It will multiply very rapidly and form dense clumps that can crowd out plants with better manners.  Others in this family that are half hardy can be safely grown as summer bulbs and stored over winter, or even left in the ground in reliably mild areas.
bulletSpanish bluebells.
bulletScilla hispanica, Endymion hispanicus, Hyacinthoides.
bulletThe experts keep disagreeing about what to call these and keep renaming them, but you must be very careful.
bulletEnglish bluebells are safe, but is that what you are really getting? These hardy bulbs form dense clumps with heavy, fleshy leaves that will smother anything trying to emerge close by. They are slug havens as well. Yes, they are pretty.
bulletBut I have seen them bloom after being left above ground to freeze during a cold snap. They don't seem to notice!
bullet Of course they are in the lily family: why can't my L. rubellums behave this way?
bulletTulips.
bulletI don't need to tell you that these carry virus. However, don't think that only the "Rembrandt" types are bad. Others can look okay the first year and come up all twisted and deformed the next, having distributed their share of virus infection. The smaller species grown from seed are the safest if you can find a source.
bulletDahlias, cannas, tropical bulbs, etc.
bulletKeep these away from all hardy bulbs. They need too much summer water to be in the same irrigation zone as your lilies.
You must also be careful with trees and shrubs.  Some can harbor pests or diseases that also attack lilies.  Beware of rhododendrons with red flowers as they are the ones most attractive to root weevils, which also love to munch on lily leaves.  Maples can carry Fusarium, especially in wet areas, and their roots are too close to the surface to be compatible with deeply planted bulbs.  Roses that are very stiff and thorny, such as hybrid teas, can rip tender bulb foliage to shreds on windy days if they are too close.

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Now that I have said what not to do, what are some good plants to pair with lilies?

This is by no means an exhaustive list, but it reflects my experience here in Oregon and I'm sure many of these plants would be welcome anywhere.  I have included some plants with beneficial qualities as far as natural pest control, to make your garden more beautiful without needing to use dangerous chemicals.  I have avoided discussion of extremely rare or difficult plants since any specialists will already know about them, and the point is lilies after all.  Most of us have enough trouble keeping lilies in good health year after year without worrying about whether the rest of the garden will live or die.
bulletEpimedium spp.
bulletThese beautiful woodland plants never get too tall and are ideal for growing at the foot of lilies which need a cool root run, such as L. superbum or L. martagon.
bulletTheir arrow-shaped foliage is interesting and you get lovely flowers as well.
bulletThalictrum spp.
bulletFerny foliage, a good match with woodland type species and species look-alikes, as well as Orientals.
bulletThey can get quite tall, but all the leaves are at the base and they are good "veil" plants if you don't want to banish the pretty columbine-like foliage to the back of the border.
bulletSweet Cicely (Myrhhis odorata).
bulletA stately herb of the umbelliferous persuasion, with all parts of the plant smelling and tasting of sweet licorice.
bulletLoves afternoon shade just like lilies.
bulletA magnet for beneficial predatory insects such as tiny wasps and ladybugs, and you can eat it too.
bulletCosmos of all types.
bulletTrouble free and attractive to birds.
bulletUse the tall pink and white ones to help support trumpets and Orientals, and use the shorter yellow and orange Klondyke types to match with Asiatics.
bulletAfter the lilies fade, the bed will still have bright color.
bulletThey are surprisingly good as cut flowers.
bulletFeverfew (Matricaria).
bulletThis pungent herb helps to repel pests, and the double types are excellent as cut flower bouquet fillers.
bulletTry to find the tetraploid varieties, which can get much taller than the common diploids (up to three feet), and carry more attractive foliage.
bulletThis plant also is attractive to beneficial insects.
bulletNicotiana (flowering tobacco).
bulletThese are wonderful garden plants, and aristocrats among annuals.
bulletTheir sweet fragrance in the evening garden is a welcome feature, and it lasts all summer.
bulletThey will be perennial in milder winter areas, developing huge fleshy roots.
bulletDon't plant them too close to your lilies for this reason, or yank them out and treat as annuals.
bulletThe taller types, N. grandiflora and N. sylvestris, are striking in tandem with taller Orientals and trumpets, and are shade tolerant as well, so they can be paired with woodland lilies or Hosta, for the coolest garden imaginable. Nicotiana langsdorffii, unlike the other two, is scentless but well worth growing.
bulletCool lime-green elongated bells hang straight down and contrast with dark blue-green foliage, the richest of the group.
bulletA planting of these with white Orientals will be a refreshing sight on a sweltering August day.
bulletAnnual poppies.
bulletAll kinds, yes, even California poppies (Eschscholzia)! These self-sow freely and can even be deemed a pest by some, but they are effortlessly removed from areas where you don't want them.
bulletThey come in a wide range of colors from hottest scarlet to pale silvery pink to compliment any color scheme.
bulletDid I mention how easy they are?  Just throw seeds around and barely rake them in, and you will be richly rewarded.
bulletAnnual candytuft.
bulletA flower that's almost forgotten these days, giving way to trendier annuals.  Get reacquainted with these little workhorses whose gentle colors and sturdy habit go with just about anything.
bulletA great choice for bedding with shorter lilies.
bulletWildflower and "scatter" garden mixes.
bulletJust make sure these are formulated for your area of the country and don't contain any invasive species.
bulletTo be on the safe side, buy only annual mixes and don't buy them from the fly-by-night companies you see in the Sunday supplement. You know who I mean!
bulletGaura lindheimeri.
bulletA lovely "veil" plant for planting near dryland lilies and rock plants, it requires excellent drainage.
bulletThe common (but not common-looking) type is white, but look for the new 'Siskiyou Pink' introduction, a stunning beauty. This lovely thing blooms for many weeks and requires almost no irrigation.
bulletPenstemon species and hybrids.
bulletMany of the species are xeric and are good with western American dryland species.
bulletWhat is not so generally known is the wide variety of hybrids now available that will do well in good garden soil.
bulletMarigold (Tagetes).
bulletThe wild types of this genus can clear the ground of nematodes when used as a cover crop.
bulletThe flowers are small but colorful, and the leaves are powerfully pungent.
bulletAmong cultivated varieties, the 'Signet' types are nice for their lemon scent and the flowers are edible.
bulletBuckwheat (Fagopyrum esculentum).
bulletNot a grain or even a grass, this plant is related to rhubarb! With shiny broad leaves and pretty white flowers in summer, it is a bee magnet.
bulletA warm weather annual, you can broadcast seeds after lilies are up to suppress weeds in full sun areas. It gets about 18 inches tall.
bulletOften called the "organic Roundup." If it grows taller than you want, just pull or cut it and lay it down as a cooling summer mulch.
bulletClarkia.
bulletA genus in the evening primrose family.
bulletGodetia (Clarkia amoena) and similar annuals.
bulletVery nice "ribbon candy" colors and can be direct sown for easy interplanting.
bulletHakonechloa macra var. aureola.
bulletOne of the few ornamental grasses I would think of trusting around lilies, it is a slow grower, noninvasive, and has a bamboo-like appearance without the behavior.
bulletIt stays low and is a knockout with Orientals. It's expensive but good for a featured planting.
bulletOther bulbs.
bulletMost Allium are great and don't attract pests.
bulletTry Allium azureum with pastel peach early Asiatic for a fabulous color combination.
bulletMost minor spring bulbs except the aforementioned Spanish bluebells are fine, and most will disappear well before the lilies are in bloom.
bulletSmaller narcissuses are a possibility, and slugs will not touch the leaves although they will eat the flowers.
bulletWoody shrubs and trees.
bulletNandina domestica is wonderful and even comes in dwarf forms for the smallest gardens. This "heavenly bamboo" isn't related to bamboo at all, but has the same grace and beauty.
bulletDeciduous azaleas provide a punch of early color and are slow growers. They do not need the quantities of summer water that the evergreens do.
bulletSpirea japonica is a low grower that keeps a neat habit and has lovely flowers that change color as they age.
bulletBuddleia davidii.
bulletcan be used if the eventual size of the plant is taken into consideration. Some newer varieties only reach about five feet tall.
bulletThe lesser known yellow ones (x weyeriana) are more branching in habit and can be used to support tall Aurelians in full sun; plant them on the "leaning" side.
bulletThe extremely hard wood can be used as garden stakes when you need to trim it back. Mahonia repens is a dwarf form of the common Oregon grape and is a great companion for shorter woodland lilies.  Check with a specialist for availability outside the northwest.
bulletPieris japonica (Andromeda, Lily-of-the-Valley bush) is available in dwarf forms now.  It carries beautifully fragrant flowers in spring and a less heavy presence than evergreen rhododendrons make it a welcome addition.

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Try these if you want to experiment:

bulletDianthus.
bulletFor lime tolerant lilies, these could be a good choice of a companion.  I can't grow them well here in my heavy acid clay but there are many varieties available for those with lighter soil. I envy those gardeners who can keep them, as their vanilla and clove fragrances are wonderful.
bulletBaby's breath (Gypsophila).
bulletThe sSame as for Dianthus. The name means, "lime loving."  The annual form is worth a try with Madonna lilies if you can grow them. The pink one is especially charming. Add Allium azureum to the combo and you've got a pretty picture.
bulletLavender.
bulletThese plants require sharp drainage, but could work with Mediterranean-type lilies. You also add fragrance and a very useful herb.  There are now some lovely pink and white forms to try: 'Melissa' is a nice white that doesn't get very tall.
bulletSouthernwood and Santolina.
bulletTry these and similar plants with the same conditions as for lavender. Southernwood is available in either a lemon or orange scent and repels pests with its strong aroma.
bulletCorsican mint.
bulletThe smallest of the mints and the only one you can really trust, as it is not invasive - a true rockery plant where it will survive and remain intensely fragrant. Keep away from afternoon shade and pair with dwarf species lilies.
bulletDaylilies (Hemerocallis).
bulletThese are great for carrying on color and flower form after early lilies are past. However, be careful about varieties.
bulletDo not under any circumstances, in any part of the country, get Hemerocallis fulva (tawny daylily) anywhere near anything! It is an aggressive spreader and very hard to remove once it forms a big clump, which it will.
bulletThe ones marketed as good for steep slopes are also out of the question.
bulletWhat you need are the really nice ones, the special ones that cost a little more. The reason they do cost more is they are slower to propagate and have good garden manners. They come in a stupendous array of colors, forms, and sizes.
bulletI like the semi-evergreen ones for Oregon, as they are usually repeat bloomers, and very often quite fragrant.
bulletMy favorite species is the pale yellow 'Citrina,' a tall, graceful plant that is the source of the spider-type daylilies.  It is wonderfully fragrant, especially at night, and blooms late in the season. It does not repeat, but don't let that deter you.
bulletI would also recommend 'May May,' a smaller-flowered creamy yellow which repeats constantly and can take some afternoon shade while blooming its pretty little head off.
bulletPeony (Paeonia).
bulletBoth the herbaceous and woody, or tree peonies, are among the most beautiful of garden perennials.  Unfortunately they can be a source of Botrytis infection, so keep them away from susceptible lilies in wet climates.
bulletThe taller ones make a great backdrop for permanent lily plantings, as their handsome leaves look good long after the flowers fade.
bulletMake sure they have enough support so they don't flop onto emerging lilies during rainy periods.
bulletRoses.
bulletI love these too much to leave them out of a garden scheme.
bulletMany old-fashioned ones have a lax, graceful habit that goes well in mixed plantings and there are others that are thornless or nearly so, thus making them safe for lilies.
bulletA particular favorite of mine is 'Brother Cadfael,' a David Austin English rose of the most delicious pale silvery pink.  The flowers are huge and very fragrant, the stems are essentially thornless, and its upright habit makes it a nice cut flower as well.  There are so many out there, just find a book or catalog that goes beyond the ubiquitous hybrid teas and you're on your way.
bulletNot that I don't love hybrid teas, but many of them just don't meet the mixed border criteria of graceful form and rude good health.
bulletVinca minor.
bulletThis is about the only plant called a ground cover that could be considered safe, as it is very low growing.
bulletThe white and violet types are less vigorous than the more common blue-purple type.
bulletThere is now a variegated one on the market if you want to go bankrupt buying it. It is supposed to behave itself; we'll see about that.
bulletBeware of the "giant" form out there as it is twice the size of the normal form and is too much for a bulb bed.

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A few more things to think about:

bulletBe aware of the eventual height and spread of anything you put near your lilies.
bulletIf you figure you can just move it later, think again.
bulletMake sure watering requirements are similar, as many lilies do not tolerate excessive summer watering.
bulletDon't plant pest magnet plants too close.  You don't want to invite them all to the same place.
bulletRemember that "flowers attract, leaves repel":  strongly aromatic foliage can help deter certain pests that like to chew on plants without such a defense when planted together.
bulletIf you have bulb beds, which you constantly replant and change, you won't want permanent companion plants.
bulletConsider the benefits of an attractive mulch, which keeps soil splash off your plants in the rain and reduces watering needs.
bulletOne of my favorites, recently available in my area is cocoa mulch.  Its rough texture deters slugs and cats don't like to walk on it. It makes the whole garden smell like a Hershey bar!
bulletIt is too expensive to use on everything, but put it around your choice plantings and in high visibility areas.  It breaks down quickly and is slightly acidic, so Orientals love it.
bulletLast year a friend gave me a very choice Hosta plantaginea 'Aphrodite' which I surrounded with a moat of the stuff.  There was not one slug hole in the leaves until the end of summer when it grew large enough to extend beyond the barrier zone.
bulletIt is great for giving lilies a head start so they can emerge and leaf out in relative peace.  By the time the mulch starts to break down the foliage will be tough enough to withstand the onslaught.

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I recommend the following books to encourage experimentation:

  1. Christopher, Tom, and Michael A. Ruggiero, Annuals with Style. Connecticut: Taunton Press, 2000. (Up to date and thorough treatment. Lots of good suggestions for combining plants.)
  2. McDonald, Elvin, The 100 Best Annuals-a Practical Encyclopedia. New York: Random House, 1995. (Good for rediscovering old favorites, an excellent antidote to the dread disease known as "annual snobbery.")
  3. Sheldon, Elisabeth, The Flamboyant Garden. New York: Henry Holt & Co., 1997. (Great photos and how-to for using hot colors, with a generous dose of humor.)
  4. Wilder, Louise Beebe, The Fragrant Garden. New York: Dover Publications, 1922. (A true classic, this little book has a wealth of information about plants with aromatic leaves as well as flowers. Worth reading if only for her comments on lilies, calling them "decadent." Delicious!)
  5. Winterrowd, Wayne, Annuals for Connoisseurs. New York: Prentice Hall, 1992. (A frank assessment of plants both familiar and new.)

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