December 2011 Culture

Crop Culture Report: Dianthus Kahori By Lida Sladkova

This strongly scented dianthus is easy to grow and flowers all summer long.

Last year, Fides Oro introduced the new dianthus Kahori: a plant with very attractive pink flowers, a great scent and hardiness to Zone 4. This plant has had major attraction from brokers, growers and retailers — a major success for this little plant. And the value for the consumer? In the garden or on the patio, Kahori flowers all summer long!

Kahori performs in 4-inch as well in 6-inch pots and is an easy-to-grow crop that can be grown outside as well. In this article you can find the keys to successful culture for this special dianthus. Kahori is available at Fides Oro as a liner or as an unrooted cutting.

Rooting

Kahori roots best in a deep 200-cell tray. Due to the size of the cutting, the 200-cell provides the best micro climate around the cutting. At sticking, apply a rooting hormone such as Hormodin 1 or Dip'N Grow at 1:9 dilution. Maintain the soil temperature during rooting between 72¡ and 74¡ F and maintain a high relative humidity.

Keep cuttings under mist for approximately 14 to 21 days. Kahori has a very sensitive root system; don't allow them to dry, but don't overwater them either. After cuttings have rooted, place liners on a bench under 70¡ F and keep moist (don't overwater). Apply 100- to 150-ppm nitrogen from a balanced fertilizer like 17-5-17. Keep the pH between 6.2 and 6.6.

Two weeks before transplanting (six weeks after sticking), trim plant to about a half inch above the tray. This stimulates branching and you don't need to touch the plant again until finishing. Including the pinch, the rooting time will be eight weeks in total. Please note that Kahori will start flowering immediately in propagation. This is NOT a problem, so you don't have to take off the buds and flowers. Kahori will always flower and at the same time develop the plant.

Finishing

After eight weeks of rooting, the liner is ready for transplanting. Kahori should be planted in well-drained soil mixes. Keep the day temperature anywhere between 65¡ and 70¡ F and during the night between 55¡ and 62¡ F. Use cool mornings to improve the plant habit and flower quality.

It is very important to not overwater plants so grow the dianthus Kahori on the dryer side. Provide 100- to 150-ppm nitrogen. Maintain your pH level around 5.8 to 6.4. The use of PGRs or pinching after transplant is NOT recommended. Again, Kahori will start flowering immediately after transplant. This is not a problem. Kahori will always flower and at the same time develop the plant.

For better display or appearance at time of sale, use shallow pot sizes.

Timing

To finish Kahori in a 4-inch pot with one pinch (see trimming advice under rooting), please take the following timing into account.

Add four weeks finishing time for every extra pinch, although this is NOT recommended and will only add to the crop time.

Pests and Diseases

The main disease threats for Kahori dianthus are Botrytis, Fusarium, Crown Rot and Pythium. Avoid fungus gnats, especially during rooting. Other important pests to be aware of are thrips, spider mites and white fly.