by Maggie Asplet
For this article I was going to be a little nostalgic as I so missed my trip to Thomas Johnson at Mid-America Iris Garden, the visits to Lynda Miller’s of Millers Manor, the wonderful visits to Chad Harris at Mt Pleasant Irises, but Melissa and Bailey from Smokin’ Heights beat me to that…
Customers often ask us, “How and when should I fertilizer my iris?”
The short answer (continue reading for the nitty-gritty): one month before bloom season, while the tulips are blooming, apply a low-nitrogen, well-balanced fertilizer, such as Schreiner’s 6-10-10 Controlled Release Iris Food. Keep the fertilizer several inches away from the rhizomes. Approximately on month after bloom season, fertilize again. That sums it up nicely, but perhaps you would like a bit more to chew on about the “what” and “when” of feeding your Iris. Read on for a more substantial serving of info on nurturing both your soil and your Iris.
There are four main nutrients that we must maintain in the soil: nitrogen, phosphorus, potassium, and calcium. The first three nutrients are found in most mixed fertilizers, and calcium can be purchased separately in the form of limestone. Nitrogen is necessary for new cell formation in all parts of a plant. Compared to other nutrients, nitrogen is typically the most lacking. A symptom of a shortage of nitrogen is yellow-green stunted growth. Potassium (potash) is necessary for strong roots and stems as well as deep flower color. A symptom of potash deficiency is weak stems and yellowing or browning leaf tips and edges. Phosphorus is necessary for development of roots and stems. This nutrient also stimulates fruit and seed production. A symptom of Phosphorus deficiency is red or purple discoloration of leaves.
Before applying any fertilizer to your garden, do a soil test to discover what your plants actually need. The best way to know how much, and at what proportion, to add nutrients to the soil is with a soil test. Simple soil tests can be purchased at garden supply centers. Once you determine what nutrients are lacking or are in abundance, you can amend the soil to correct most problems. Your soil test may also reveal a need to correct pH or add trace minerals, for example. Completing a soil test, and making modifications to your soil based on the results, is the preferred method to determine fertilizer amounts.
Fertilization of Iris is important to obtain best results, but must be done in moderation. The only thing Iris may resent more than underfeeding is overfeeding. Nitrogen, potash, and phosphorus are essential for Iris, but excessive nitrogen promotes lush growth that is more susceptible to rot diseases. If applied in concentrated form, do not allow the fertilizer to come in direct contact with foliage and roots, as the plant may be damaged or killed. Low-nitrogen fertilizers, such as 6-10-10, are ideal for the needs of Iris.
When to apply fertilizer to Iris:
1) In the spring, about a month before bloom, apply a light application of fertilizer around the Iris clumps. This goes for dwarf iris, too, which bloom in March. Apply a low-Nitrogen fertilizer to your dwarf iris in mid to late February. Apply the same to your intermediate and tall bearded iris in intervals coinciding with the month before their bloom cycles.
2) At planting, sprinkle a tablespoon of the fertilizer around the newly planted rhizome. Or, if preparing a large area for iris planting, incorporate ½ lb of a low-nitrogen fertilizer such as 6-10-10 per 50 ft2 (or 1 ½ oz per 10 ft2) to your garden bed.
3) After your Iris bloom is another time you should fertilize them. Doing so keeps them healthy and in tiptop shape for better growth for the growing cycle later in the year. Wait a month or so after blooms have finished, or in the fall, with enough time before winter so the Iris have the proper nutrition they need going into their winter dormancy.
Here’s a little more info on the subject of fertilizing, including a short video with Ben Schreiner showing us how and when to feed your iris
Now that you’ve got the scoop on Iris nourishment, you can take the necessary action to feed your hungry Iris. Schreiner’s Gardens offers a specially formulated Iris food to help you provide balanced nutrition in the flower garden. Order now for summer and fall shipment.
Yours in gardening!
By Kevin Vaughn
Amoenas and variegatas have long been favorites of iris growers. The early amoenas and variegatas were all derived from I. variegata and had many problems associated with that species, chiefly very veined hafts, and a pattern of striped falls rather than solid ones. Breeders were persistent in their work, despite poor germination of…
By Bryce Williamson
My second stop on the 2019 tour of iris gardens in Oregon and Washington was the garden of Keith Keppel in Salem. For many years, Keith Keppel’s garden in Stockton was a must visit destination. With his retirement from the US post office, Keith made the huge move to Salem, Oregon. While he was…
By Sylvain Ruaud In Italy iris hybridizing is not a new activity. But as you are about to find out, over the years it has taken its own — very original — dimension. Everywhere else in Europe it is men who have dedicated their lives to irises, certainly with enthusiasm and passion, but also as a…
By Ron Killingsworth and Patrick O’ConnorWhere, oh where, did that name originate? Iris names have always intrigued me. Some names are easy to figure out. Others defy reason. Another interesting subject is people’s names. Where in the world did the parents get the name they stuck on that poor child? Have you often wondered that? That subject…
By Mike Unser
A selection of irises I have grown that were introduced in the year 1926. In the United States Grace Sturtevant and Bertrand Farr were working in the east, EB Williamson and the Sass Brothers in the mid-west, and Mohr and Mitchell in California. England’s own Arthur Bliss was thrilling European gardeners, as were…
Congratulations to Mike Sutton and Sutton Iris Garden!
The American Iris Society Announces the 2019 Dykes Medal Winner ‘Bottle Rocket’ (Mike Sutton 2009)
First awarded in 1927, the Dykes Medal is the highest award of the AIS, awarded to no more than one iris per year. Irises are eligible as a Dykes Medal candidate for three years following the winning of a classification medal. Only AIS registered judges…
by Jean Richter
This is an introduction to three women iris hybridizers from the 20th century who are perhaps not particularly well known, but all created iris of great beauty.Our first hybridizer is from the earliest era of the American and British Iris Societies, in the early part of the 20th century.Miss Violet Insole was a…
Link to blog post on building iris beds: https://wordpress.com/read/feeds/35117626/posts/2283390036
Thank you for your patience.
~ Schreiner’s Iris Gardens