November 2010 Culture

Stachys macrantha ‘Morning Blush’ By Paul Pilon

If you have not been a huge fan of the fuzzy leafed lamb's-ears type stachys typically grown in the past, put those thoughts to the side because there are some exciting and very marketable species of stachys available today. Stachys macrantha 'Morning Blush' is a recent introduction from Jelitto Perennial Seeds that has great potential for commercial growers and landscapes across the northern half of the United States and parts of Canada. 'Morning Blush' produces dozens of clustered spikes of pink-flushed tubular blooms over basal clumps in the late spring and early summer. The attractive dark- green foliage is heart-shaped with crenated margins. The dense foliage grows to four inches tall and the plants reach 14-16 inches in height when in bloom.

Stachys macrantha performs well across USDA Hardiness Zones 4 to 7 where they prefer to be grown in full sun; in southern locations, it is best to place them under partial shade. It thrives in any garden soil that is well drained. 'Morning Blush' is valued for its attractive and long-lasting floral display. It can be used as an accent plant, in small groups in the front of a perennial border, or allowed to spread as a groundcover.

Propagation

Stachys 'Morning Blush' is propagated from seed. Growers commonly sow two to three seeds per cell in 128-cell or larger sized plug trays. Cover the seeds lightly with germination mix or medium grade vermiculite to help keep the seed moist during germination.

It is a cold germinator and requires special treatments to encourage more uniform germination. After sowing keep the seed flats moist and maintain 64-72¡ F for two to four weeks. After this period, move the flats to a cold environment where the temperatures can be maintained between 25¡ and 39¡ F for four to six weeks. After the cold treatment, move the flats to back to a warm environment where the temperatures can be maintained at 65-68¡ F for germination.

Jelitto Perennial Seeds offers Stachys macrantha 'Morning Blush' as Gold Nugget seed, which is pretreated to help improve the germination rate and bypasses the need for stratification. Gold Nugget seed can be sown one to two seeds per cell and kept moist (not wet) and at warm temperatures (65-68¡ F) for germination.

It takes eight to 10 weeks for germination of untreated seed or two to four weeks for Gold Nugget seed.

Following germination, reduce the moisture levels somewhat, allowing the growing medium to dry out slightly before watering to help promote rooting. The temperature can also be reduced to 62-67¡ F after germination. Fertilizers can be applied once the cotyledons are fully expanded, applying 100- to 150-ppm nitrogen every third irrigation or 75 ppm with every irrigation, using a balanced water-soluble source. When plugs are grown at 65¡ F, they are usually ready for transplanting five to seven weeks after germination.

Production

Stachys 'Morning Blush' is best produced in one gallon or smaller sized containers. A single plug can be planted into small container sizes or two plugs per pot should be planted into one gallon pots. To encourage branching, it is beneficial to pinch the plants prior to or shortly after planting. They prefer to be grown in a well drained growing mix with the pH maintained between 5.8 and 6.4. Stachys require an average amount of irrigation and do not tolerate really wet or overly dry growing conditions. Keep them moist, but not consistently wet.

'Morning Blush' requires light to moderate fertility levels. Growers commonly deliver nutrients using water soluble fertilizers feeding constantly with rates of 50- to 75-ppm nitrogen or applying 150 ppm as needed. Controlled-release fertilizers can be incorporated into the growing mix prior to planting at a rate equivalent to 0.75 to 1.0 pounds of nitrogen per yard of growing medium.

With their compact growth habit, it is not necessary to control the plant height. Plant quality can be maintained or improved when they are grown at minimal plant spacing.

Insects and Diseases

Aphids, caterpillars and cyclamen mites may occasionally be found feeding on Stachys. The primary diseases likely to infect them include powdery mildew, Rhizoctonia, rust, Sclerotium and various leaf spot pathogens. These insects and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless the scouting activities indicate actions should be taken. Many of the diseases can be avoided with good moisture management and by ensuring the foliage is dry prior to night.

Forcing

Flowering plants of stachys 'Morning Blush' can easily be produced by following these guidelines. They have an obligate cold requirement for flowering. Stachys can be vernalized in the final container or as large plugs (72-cell or larger) for a minimum of nine weeks at 35-44¡ F. I recommend growers plant them in the late summer or early fall the year before they are to be sold to allow them to bulk up prior to being vernalized.

Although, the photoperiod necessary for flowering has not been researched or documented, it is believed that 'Morning Light' is a long day beneficial plant. To improve the appearance and flowering when the natural day lengths are short, provide day extension (minimum 14 hours) or night interruption lighting. The time to bloom after the proper photoperiod is provided is a function of temperature. It takes approximately six to eight weeks to reach flowering when they are grown at 65¡ F.

Availability

Untreated and Gold Nugget seed of Stachys macrantha 'Morning Blush' are currently only available from Jelitto Perennial Seeds (www.jelitto.com). The availability of plugs is limited at this time, but should become more widely available as more plug growers add it to their perennial programs.