September 2025 Culture, Production, Variety Info

Culture Report: Dianthus ‘Kiwi Mellow Cool’ By Jose Sanchez

Dianthus are a long-lasting addition to any floral arrangement. From bouquets to garlands to other creative designs, the wide-reaching color palette allows designers to be whimsical and artistic. In cool and temperate climates, dianthus can be produced all year — and the plants are highly productive. They make great solid bunches and hold up to shipping and delivery well. 

At Ball Seed, our cut flower team partners with a vast range of breeders and builds supply relationships to bring cut flower growers varieties to fill their programs, including products from our exclusive partnership with Selecta One. The increased access to supply through the USDA approval of the Selecta One Kenya production farm means higher quantities available to growers in North America. 

With an assortment that represents the traditional to contemporary, one of the recent highlights from Selecta One is becoming a favorite with Ball Seed customers. As they say in their catalog, ‘Kiwi Mellow Cool’ is “as cool as it gets” with its modern green color and touchable texture. 

This Dianthus barbatus has exceptionally large, 3- to 4.25-inch, perfectly ball-shaped flower heads on straight, strong, distinguished stems. It adds volume to cut flower designs and is a standout accent to any floral bouquet — not to mention its long vase life. 

Adding cut flowers or supporting cut flower farmers is one way grower-retailers can expand their businesses. Below are some cut flower production guidelines to help you grow and sell successfully. 

FIELD PRODUCTION 

Planting density should be 2 to 4 plants per square foot. 

Plant in rich, well-drained soil with good aeration, not much humidity and a pH between 5.8 and 6.5. 

During this first stage, the plant presents a higher demand on nitrogen so it’s recommended to apply calcium nitrate CN (N03) 2 per 200 ppm. Stringing of two to three beds should be used to guide the stems along the growth of the plant. Support is important because this is a tall and heavy crop. 

Two to three weeks after transplanting (week 6 to 7) — and/or after reaching a height of 4 inches or eight pairs of true leaves — the pinch should be done on the third internode, or three pairs of leaves, removing the apical growth meristem. To obtain better results and better quality, it is important to make a selection leaving five to seven stems on the plant (depending on the quality and market). 

Pinching and selecting will yield three to five stemsper plant. 

An alternative production option if you choose not to pinch, will yield a good quality one-stem per plant crop.

NUTRITION 

As mentioned, Dianthus barbatus have a very high demand of nitrogen in the early stages. However, an excess of nitrogen could make them sensitive to disease and an increase of shoots. Nitrogen applications should be done twice per week at a dosage of 180 to 220 ppm based on nitrates. 

At the first stages of growth, phosphorus is also important; it increases the growth of the stem and roots. Ammonium phosphate is also recommended to add N (18-46-0). For increased plant vigor, potassium is recommended at a dosage of 22 ppm. 

MARKET OPPORTUNITIES 

The cut flower market continues to experience significant growth, driven in part by the consumer’s focus on locally sourced options. A versatile flower like dianthus, and especially a quality, unique offering like ‘Kiwi Mellow Cool,’ can add to your bottom line. The vase life and durability of dianthus make it very appealing. Its high demand in a reliable market, paired with its easy production, make dianthus a must-have in your assortment.