June 2013 Culture

Perennial Solutions: Kniphofia uvaria Echo Series By Paul Pilon

The perennial commonly referred to as the torch lily or red-hot poker is an old fashion perennial which has not become as popular as many of the perennial genera in production today. Although they are very showy when in bloom, the appearance of past cultivars declined rapidly after the flowers senesce.

Moving forward to present day, the breeding and selection efforts of Richard Saul of ItSaul Plants Inc. has brought kniphofia Echo series to the marketplace. The Echo series is currently comprised of three cultivars: ‘Echo Mango’ with ripe mango-colored flowers, ‘Echo Rojo’ with deep-orange to red flowers, and ‘Echo Duo’ with two-toned orange and fading-to-white colored inflorescences. Each of the Echo cultivars provide good disease resistance, produce vivid-colored flowers atop sturdy stems and are strong rebloomers. The series name Echo refers to the repeat flowering nature of these plants.

In the landscape, well-established clumps of the Echo series have gray-green, evergreen, long and sharply pointed foliage which grows two feet across and produces flower spikes 3 feet in height.

They grow quickly, but not too aggressively. When blooming begins in the late spring, the plants produce an abundance of torch-like flowers, and they continue to bloom all summer long. They are more ever-blooming than repeat bloomers.

Kniphofia perform best in sunny sites with moderate to dry soils throughout USDA Hardiness Zones 5 to 9. They can tolerate heat and humidity quite well. Although they are fairly drought tolerant during summer dry spells, it is best to provide some irrigation during these periods.

The torch lily is an ideal candidate for specimen or border plantings. It can also be used in container plantings or as cut flower. If critters are a problem, kniphofia is resistant to feeding from both deer and rabbits. Additionally, the flowers are full of sweet nectar which butterflies and hummingbirds cannot resist. With its big, colorful flower display for an extended period, kniphofia Echo series would make a great addition to both perennial programs and landscapes across the country.

Propagation

The kniphofia Echo series cultivars are vegetatively propagated by means of tissue culture. Tissue culture allows them to be grown with great uniformity. This series is patented and unlicensed propagation is prohibited.

Production

It is best to produce the Echo series in large container sizes; they are commonly grown in 1- to 2-gallon pots. When planting, the growing medium should be even with the top of the original liner. Torch lily performs best when grown in a porous, well-drained medium with a slightly acidic pH: 5.5 to 6.5. Many commercially available peat or bark based growing mixes work well provided there is good water holding ability and more importantly, adequate drainage.

Although they can be somewhat drought tolerant in the landscape, kniphofia prefer to be kept slightly moist when they are grown in containers. When irrigation is necessary, water them thoroughly then allow the soil to dry moderately between irrigations. Once they are fully established, they can be allowed to dry down further.

Torch lilies are moderate feeders. Nutrients can be delivered using water-soluble or controlled-release fertilizers. Growers using water soluble fertilizers can apply 100- to 150-ppm nitrogen with every irrigation or use 200 to 250 ppm as needed. Reduce the fertility by approximately 50 percent in the fall prior to overwintering. Controlled-release fertilizers are commonly incorporated into the growing medium prior to planting at a rate equivalent to 1 to 1.25 pounds of elemental nitrogen per yard of growing medium.

The Echo series produces a tall plant when it is grown in containers and marketed in bloom. To maintain plant quality, commercial growers can combine both cultural and chemical methods of controlling plant size. The first approach to reducing undesirable plant stretch during production is to provide adequate spacing. Additionally, the height can be reduced to some extent by withholding nutrients (namely excessive levels of ammonium forms of nitrogen and phosphorus) and water.

To produce more compact and sturdier plants, it may be necessary to apply plant growth regulators. Depending on geographic location and the amount of height control needed, spray applications of 30- to 45-ppm paclobutrazol (Bonzi, Paczol or Piccolo) or 5- to 7.5-ppm uniconazole (Concise or Sumagic) can be applied to tone the plants or to effectively control plant height. In most instances, it will require multiple foliar applications to obtain adequate height control.

Insects and Diseases

Compared to many perennials, there are only a few problems with insect pests or plant pathogens which growers may come across on occasion. Aphids, spider mites and thrips are the most common insects growers are likely to see during production. Alternaria, Botrytis and Sclerotium are the most common diseases to infect kniphofia. All of these pests and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless the scouting activities indicate actions should be taken.

Scheduling

Kniphofia Echo series is usually produced for late spring to early summer sales. When producing them in 1-gallon or smaller container sizes, they can either be planted in the late summer the year before they are to be marketed or during the same growing season. When they are being grown in large container sizes (8-inch or larger), it is best to bulk them up in the fall prior to the spring they are to be sold. Allow at least six weeks for bulking prior to the vernalization period.

Kniphofia do not require cold for flowering but are considered to be cold-beneficial plants. Plants that have been vernalized will flower more uniformly. Torch lilies will flower under any photoperiod; however, the best flowering occurs when they are grown under long day lengths.

Plants can be bulked up in the fall and overwintered or transplanted in the spring using vernalized or unvernalized liners. They will flower under any photoperiod and can be forced into bloom under natural day lengths. Fall plantings can be forced into bloom in seven to eight weeks when they are grown at 65 to 68° F; spring plantings using unvernalized liners will take approximately nine to 10 weeks to bulk up and flower.

Availability

Liners of Kniphofia Echo series are available from AG3 Inc. (www.ag3inc.com), Green Leaf Plants (www.glplants.com), ItSaul Plants (www.itsaulplants.com), James Greenhouses (www.jamesgreenhouses.com), Pacific Plug & Liner (www.ppandl.com), and Skagit Gardens Inc. (www.skagitgardens.com).