By Kerry A. Mendez
Q:Are there any perennials for shade that bloom in the fall? My shade gardens look pretty good most of the season, but peter out by September.
A:Welcome to the challenge of getting three seasons of bloom from shady perennial gardens. Most shade perennials bloom in the spring or early summer before trees leaf out heavily. By late summer, most of the color in shade gardens is provided by annuals or showy foliage. But there are a few plants that will provide a floral encore. Toad lily (Tricyrtus) has darling, orchid-like flowers that are usually white or pink with purple spots. Tricyrtus ‘Gilt Edge’ goes one beauty step farther with its cool gold-rimmed leaves. Yellow waxbells (Kirengeshoma) displays dangling, soft yellow flowers on a three-foot tall, shrub-like plant with maple-shaped leaves. The monkshood (Aconitum) family includes a number of cultivars; some bloom in the summer and others wait until cooler weather to do their thing. Monkshood ‘Spark’s’ (violet-blue) and carmichaelii ‘Arendsii (deep blue) are two late bloomers that soar to 4’ to 5’. Eupatorium r. ‘Chocolate’ is typically sold as a sun to part sun perennial, but I have it in my filtered shade bed and it does great. It has chocolate foliage with dainty white flowers and reaches 3’to 4’. Lily turf (Liriope) has pretty purple spikes and grassy foliage. It only gets 12” – 18” tall and is hardy to zone 5. Liriope ‘Silver Dragon’ has stunning silver and green leaves that glow in the shade. To supplement flower color in the fall, I plant some shade-loving annuals that do not require deadheading, such as impatiens, browallia and tuberous begonias.
Q:My delphiniums only seem to live a year or two and then they die. Am I doing something wrong?
A:Welcome to the world of short-lived perennials. I know that sounds like an oxymoron. Despite the fact that perennials are supposed to live for many years, there are some that call it quits early. Delphiniums are one. Others are blue flax, verbascum, broad-leafed coreopsis (tickseed), pincushions flowers, basket-of-gold (aurinia), lupine and many shasta daisies. Most delphiniums live for two to three years in our area. If you get more than that, give yourself a pat on the back. Delphiniums demand good drainage, especially in the winter. Wet feet spell death for them. They do best in full to part sun and benefit from a May application of time-released fertilizer. I use Plant-Tone (organic) or Osmocote 14-14-14. Simply scratch one of these into the soil around their base and water in well. This will provide these heavy feeders with an ongoing supply of nutrient for three to four months. If you get sick of replacing these finicky perennials, you can substitute some tougher look-alikes. Agreed, the following don’t exactly resemble delphiniums, but use your imagination. Nice choices include monkshood (please note that all parts of this plant are poisonous); acanthus hungaricus (Hungarian bear’s-breech, zone 5); alkanet (anchusa ‘Loddon Royalist’, a biennial); salvia pitcheri (zone 5); and false blue indigo (baptesia).
Q:How do I get rid of bishop’s weed in my garden? It is mixed in among my perennials.
A:I know there are some positive uses for bishop’s weed (aegopodium),but as far as I’m concerned the plant should be OUTLAWED. It is an invasive thug to the 10th degree. There are a number of ways to tackle this headache-giver. You can use a post-emergent weed killer. Burnout and Nature’s Avenger are two organic choices. Roundup is the chemical version. Post-emergent weed killers are sprayed on the leaves. Be careful not to use it on breezy days; it will annihilate anything it touches. To kill plants in a tight spot where it is difficult to spray, put on rubber or plastic gloves, then put on cotton gloves over these and dip your hand into the solution. Simply touch the leaves (upper and lower surfaces) and say bye-bye. You can also “paint” the liquid on with a small paintbrush. Another option is hand pulling. Tiresome and frustrating I know, since bishop’s weed has long white roots that twist through the soil. But, the good news is if you keep pulling at the new top growth as it appears, eventually the plant will die as it uses all the food stored in its roots. If the thug has weaved itself into the center of a perennial, the best way to get at it is to dig the perennial up, shake the soil from around the roots, pull out the bishop’s weed and then replant the perennial. Even though this takes more time and effort, it is really the only safe way to get at the trespasser.
Kerry Mendez is the owner of Perennially Yours and is a teacher, writer, speaker and consultant residing in Ballston Spa. To learn more about her work, please visit her web site at www.pyours.com .