c
ulture onnection
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crop culture report:
Alcea Spotlight Series
Classic staples in the garden, hollyhocks have been around for thousands of years. Jelitto improves on their old-fashioned beauty with these tall, strong and colorful varieties.
By Allen Bush
fail to attract the attention of our ear- liest collectors of exotic plants…” These collectors probably found them along the Silk Road traveling from Turkey into China. Even now, gardeners can seldom walk through a garden center or look through a perennial catalogue without fi nding a few hollyhocks. Gar- deners have been planting them for a long time. There are Neanderthal remains of hollyhocks, from archaeo- logical excavations in Iraq, dating back more than 60,000 years ago. It wouldn’t be unkind to call them old-fashioned; this
I
classic’s popularity is undimin-
ished after all this time. Gardeners like them because they
are easy to grow, fl ower the fi rst season and self-sow around the garden; chil- dren can make dolls’
skirts out of
the cup-shaped blooms from May to October; and growers can easily pro- duce salable plants within 12 weeks. Jelitto has had a passion for alceas
for many years. The 2010 catalog includes a wide selection, from wild species to popular older, double- fl owering strains. Breeding on the single-fl owering Spotlight series began in 1992; though the task was challenging, General Manager Georg Uebelhart felt that the development of consistent strains in straight colors of Alcea rosea would be worth the effort. The result is consistent single fl owers of the darkest black-purple (‘Black Knight’), pure white with yellow eye (‘Polarstar’), red colors (‘Mars Magic’)
From top: ‘Black Knight’,
‘Mars Magic’, ‘Sunshine’
‘Polarstar’ and
t’s hard to improve on Henry Phil- lips’ praise of hollyhocks in 1824’s Flora Historica, where he wrote: “Its noble size, majestic height and splendid fl owers could not
and light yellow (‘Sunshine’). The Spotlight series grows nearly
6 feet tall and is a strong, recogniz- able presence in the cottage garden or at the back of any perennial border in well-drained soils. The series combines magnifi cently together, in the full sun with echinacea ‘Hula Dancer’, Eupa-
torium fi stulosum ‘Ivory Towers’ and
helianthus ‘Lemon Queen Strain’. The Spotlight series is hardy throughout North America from Zones 3 to 9.
Scheduling
Jelitto’s
seed technology greatly
improves mechanical handling and seed sowing. The alcea Spotlight series can be sown any time and requires four to six weeks for germination. Sow two to three seeds per cell in 72- or 128-cell plug trays, then maintain warm green- house temperatures of 68-75° F for fi ve days. Germination will be more consis- tent if exposed to moist, cooler temper- atures (33-41° F) for two to three weeks after the brief warm period. Allow four to six weeks from germination to trans- plant in 4- to 5-inch containers; or two plants per gallon size. Plants can be fi n- ished in an additional four weeks.
Culture
Traditional perennial growers sow
alceas in the late summer in order to vernalize over the winter, either in large plugs or in fi nished containers. Others prefer a quick crop sown in winter for the spring market. Vernalization is not essential but will improve quality. Use a well-drained media that won’t
become overly saturated. The Spotlight series will quickly produce a healthy root system in a bark and perlite mix
with pH of 5.8-6.8. Hollyhocks are not heavy feeders, and balanced 150- to 200-ppm nitrogen will promote suffi - cient growth. Maintain an E.C. of 0.6- 0.9. Keep the plugs moist following transplant, but do not overwater. A constant feed of 50-ppm nitrogen
can begin two weeks after germination and can be increased to 75-100 ppm twice a week with an EC of 1.0 in the third week until
transplant. Fertilize
with a balanced constant feed at 100- 150 ppm once a week in the green- house with an EC of 1.5. For outdoor production, apply 13-13-13 slow-release fertilizer at a rate of half a teaspoon per quart size or 1 teaspoon per gallon.
Growth Regulation, Disease and Insect Control
Allow the plants to dry out thor-
oughly between watering to prevent the telltale orange spores of the rust disease Puccinia malvacearum, which can be a foliar nuisance but needn’t be a green- house problem. Alceas are not prone to root diseases, though anthracnose and cankers have been reported. Slugs and Japanese beetles can skeletonize garden foliage but shouldn’t affect plant pro- duction. Pay attention to spider mites in the greenhouse. The simplest control for height and for Puccinia is cutting back the foliage once the lobed leaves have nearly covered the surface of the containers. This reduces the incidence of rust in the greenhouse and is also an effective deterrent in the garden. GPN
Allen Bush is North American man- ager at Jelitto Perennial Seeds. He can be reached at
abush@jelitto.com or 502.895.0807.
36 GPN May 2010
www.gpnmag.com
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