‘Midnight Treat’ iris is a distinctive and dramatic addition to any garden. Its deep coloration and elegant form make it a focal point in perennial beds.
Discovering Midnight Treat Iris
The ‘Midnight Treat’ iris is a Tall Bearded (TB) iris, introduced in 2006 by Schreiner. It typically reaches a height of about 36 inches (91 cm). The bloom features mid-purple standards and velvety purplish-black falls, edged with a lighter shade of purple. This striking contrast creates a dramatic effect. The flowers are large and ruffled, measuring approximately 6.5 inches across, with dark purple beards blended into the falls. It provides vibrant color from mid to late spring.
Planting Success for Midnight Treat Iris
‘Midnight Treat’ iris thrives in full sun, requiring at least six to eight hours of direct sunlight daily for blooming. While it can tolerate some partial shade, especially in hotter climates, insufficient light hinders flower production. Good air circulation also helps prevent disease.
Well-draining soil is essential for ‘Midnight Treat’ iris, as rhizomes are prone to rot in overly wet conditions. An ideal soil pH is slightly acidic to neutral, around 6.8, though irises are tolerant of a range of soil types. Prepare the bed by loosening the soil to a depth of 12 to 15 inches and incorporating compost or aged manure to improve drainage and fertility.
When planting, position rhizomes at or just barely below the soil surface, with the top visible or thinly covered with about an inch of soil, particularly in hot regions. Spread roots out and point them downwards in the hole. Plant individual rhizomes or groups of three about 1 to 2 feet apart to allow for future growth and airflow. After planting, water thoroughly to establish the roots.
Nurturing Your Midnight Treat Iris
Water ‘Midnight Treat’ iris consistently during dry periods, though established plants are drought-tolerant. Deep watering once every week or two during dry spring and summer is sufficient. Avoid overwatering, as excessive moisture contributes to rhizome rot.
Fertilization should focus on low-nitrogen formulas, such as a 6-10-10 mix, as high nitrogen promotes foliage growth at the expense of blooms. Fertilize in early spring or just after blooming, spreading a small handful around the plants and mixing it into the soil. Avoid using fresh manure, especially if drainage is a concern.
Deadhead spent blooms to conserve the rhizome’s energy. After flowering, cut stems to their base, but do not trim leaves, as they photosynthesize for next year’s growth. Divide mature clumps every three to five years to prevent overcrowding and maintain bloom production, as overcrowded plants often fail to bloom.
For winter preparation, remove all dead foliage and debris from around plants in late fall. This eliminates overwintering disease spores and insect eggs, contributing to overall plant health.
Troubleshooting Midnight Treat Iris Problems
Rhizome rot is often caused by excessive moisture or poor drainage. Symptoms include soft, mushy rhizomes, yellowing leaves, and wilting foliage. To address this, remove soil around the affected rhizome, scrape out soft tissue, and allow the area to dry. For severe cases, dig up the plant, clean the rhizome, and soak it in a 10% bleach solution (1 part bleach to 9 parts water) before drying and replanting.
Iris borers are a significant pest, with larvae tunneling into leaves and eventually the rhizomes, leading to brown streaks, collapsed foliage, and a foul-smelling, mushy rhizome. Eggs overwinter in leaf litter, so thorough fall cleanup is a primary control method. In spring, inspect new foliage for pinprick holes or water-soaked streaks, and crush any larvae found inside the leaves. Beneficial nematodes can also be applied as a biological control.
Fungal leaf spot appears as brown or black spots on leaves, which can enlarge and cause dieback. Repeated infections can reduce plant vigor. Good air circulation, proper spacing, and avoiding overhead watering help prevent this issue. Remove and destroy infected foliage throughout the season and in the fall to minimize spore survival. Fungicides containing chlorothalonil or myclobutanil can be applied if widespread.
Non-blooming issues stem from several factors, including insufficient sunlight, planting rhizomes too deeply, or overcrowding. Irises require at least six hours of direct sun to produce flowers. Ensuring rhizomes are planted with their tops exposed or just barely covered, and dividing overcrowded clumps every few years, are key to encouraging consistent blooming.