December 2002

Anthuriums Reinvented By Rick Schoellhorn

Somewhere between the explosion of the foliage industry in the70s and the changing of the interiorscape market, many of us lost touch withwhat was happening in the world of foliage. I have recently been working onrenovating our conservatory/teaching collection here on campus in Gainesvilleand, in the process, rediscovering some of the standards of the foliageindustry. In the process, I’ve found out how many of the interior plantcultivars I learned about 10 years ago are no longer in production. Itshouldn’t surprise me that the foliage industry’s changes have been keepingpace with the bedding plant market, but it’s a lot like visiting friends andseeing how much their children have grown; changes always seem to happen fasterin other people’s houses than they do in your own.

Anthuriums are one of the crops where a lot of changes havetaken place in the last 10 years. Breeding has really changed the face of thiscrop, but also, there are a lot of misconceptions floating around out therethat have limited the adoption and use of this wonderful flower. Anthuriumsremain one of the crops that most Northern nurseries bring in as pre-finishedor finished, but the sparsely flowered forms of years ago are long sincereplaced by earlier and heavier-flowering varieties. There have also beenmassive changes in the number of colors available, as well as the growth habitsand sizes available. A lot of the breeding advances have been made by one ofthe University of Florida’s own breeders, Dr. Jake Henny, at the Mid-FloridaResearch Center. I mention his name to give him credit for some reallyexcellent cultivars, but also to yank his chain a little as I am sure he wouldprefer I not go on about him too much! Smile Jake!

The New Anthurium

At first glance, the biggest changes with this crop seem to bethat the newer cultivars have smaller, and a lot more, flowers than the olderforms, which is true in some respects and not the whole story in others. Thetrue advances are in early-flowering cultivars, so we can now have 4-inch potsof anthurium in full flower. However, the flowers are not necessarily smaller;the new hybrids just begin flowering so much earlier that you’d think they weredwarf or smaller flowers. If you grow these plants out in larger containers,their flowers get larger as the plant gets larger, up to a certain point.

I was recently touring NGM Enterprises in Apopka, Fla., anursery specializing in anthurium as finished product from 4- to 10-inch. WhileI was there, I noticed that a lot of the cultivars I had assumed weresmall-flowered had beautiful, large flowers when grown out in largercontainers. If you are looking for some impressive specimen flowering material,you should really check out the larger container sizes.

Anthurium flowers are typical of plants in the familyAraceae. Members of this family have a distinctive flower structure composed oftwo main parts: The spathe is a modified leaf (this is the brightly coloredportion of the flower), and the spadix is the column-like spike of the trueflower parts. The color range of the spathe has been expanded from the red,pink and orange tones of the past into deep burgundy, rich purple, coral, clearpink and bi-color forms. All of these colors are presented as thick, rich, waxyblooms from 1-11 inches across. The average flower lasts up to 10 weeks, andanthuriums also make excellent cut flowers. ‘Ramona’ is a hybrid from K.P.Holland/Foremost Co. that has a crested spadix, so each flower is slightlydifferent. The “witch’s broom” effect really adds a lot of interestto this flower.

Production of anthuriums is somewhat specialized. First ofall, they are a slow crop, taking somewhere around nine months to produce a6-inch pot from a 72-cell liner. It is due to this long production time thatmost Northern growers and florists ship-in finished material rather thangrowing their own plants. The very cleanest production facilities are essentialthroughout production, as small plants are susceptible to bacterial and fungalproblems. Plants begin as tissue culture liners and are grown out as 4-inchmaterial. Plants are shifted to larger containers as they grow, so that lastyear’s 4-inch crop may be next year’s 6- to 8-inch crop, depending on the vigorof the cultivar.

Debunking the Myths

There are a number of misconceptions in the industry aboutwhat anthuriums need to perform at their best. While they are tropical and doneed warmth and high humidity to flourish, here are some things they don’tneed.

Misconception #1.Anthuriums are low-light plants. The key to continued flowering is bright,indirect light. Yes, you want to avoid direct northern sun as it will scorchthe foliage, but by the same token, don’t assume the plant needs to be kept inthe dark. Lack of light is the major reason anthuriums stop flowering.

Misconception #2.Anthuriums need lots of water. Keep these plants on the dry side; they like todry out between watering. It has a lot to do with their thick, fleshy rootsneeding air and rotting if kept too wet. All in all, it is better to slightlyunder-water than to over-water. Anthuriums are not drought-tolerant, so don’tgo overboard; leaf tips may scorch if plants become too dry. It is also notnecessary to repot anthuriums as, in most cases, they prefer to be root-bound,and this helps to avoid over-watering.

Misconception #3.Anthuriums need a lot of fertilizer. Anthuriums are actually pretty lightfeeders, needing only between 75-200 ppm nitrogen as a regular feeding. Try tostick with a 1:2:1 ratio fertilizer, and occasionally flush the soil with clearwater to keep the soluble salt level low.

Sizing Anthuriums

Anthuriums for 4-inch sales. Remember that most cultivars begin life as 4-inch pots before beingshifted into larger pots. Therefore, most cultivars can be grown as small pots,but certain cultivars flower more vigorously in small pots than others. Thereis a new series out from Oglesby called ‘Small Talk’; bright colors and earlyflowering allow it be produced in 4-inch or larger pots.

Anthuriums for 6-inch sales. Most current cultivars work well in a 6-inch pot, but some producemore flowers and offer more color than others. Here are a few to look for ifyou want 6-inch material. Try ‘Orange Hots’ and ‘Red Hots’ for amulti-flowered, bright, tropical effect; these are from the University ofFlorida’s Dr. Jake Henny’s breeding program. Also, check out ‘Anouke'(Rijn/Milestone Agriculture) and ‘Ms. June’ (Agristarts) for rich purple tones.Twyford’s ‘Tropic Fire’ was a strong red, as is Agristarts’ ‘Miami Beauty’.

Anthuriums for 8- to 10-inch sales. These are the cultivars for really outstanding,large flowers and dramatic foliage. While any of the above cultivars is likelyavailable in larger pots, I really was impressed with Milestone Agriculture’s’Sarah’, with peach- and green-mottled blooms up to 12 inches across;’Cleopatra’ was a magnificent pure white with 6-inch blooms and deep greenfoliage; and ‘Red Love’ was also excellent with high contrast between the redand green portions of the flower. The flowers on these cultivars often age backinto green tones, so they last longer on the plant and provide a verylong-lasting tropical color.

As I had just begun my annual trip around the state ofFlorida to look at poinsettia crops, I couldn’t help but look at the brilliantred anthuriums and think the ultimate heresy? “Why can’t theseplants also be used as holiday items?” The white forms are stately, thecolored types are vivid, and they last many months instead of weeks. All ofthis not only tells you this is a good upper-end crop but that we can probablyexpect to see more of this plant in the future. Just as orchids and bromeliadshave become commodity crops available in most nurseries and mass-marketoutlets, I think you’ll be seeing a lot more anthuriums in the future as well.