For the Love of Iris

Articles, Tips and Notes from Schreiner's Iris Gardens

Preparation for Planting

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Replanting Schreiner's Iris GardensA successful Iris garden, or any garden for that matter, begins with proper preparation. As we lovingly pack your Iris for shipment, it’s time for you to prepare your beds for planting. Keep these simple tips in mind:

Choose a location: Iris like to bask in the sun. Choose a location for planting that will receive about 6 hours of sun a day. In extremely hot climates, some shade is beneficial, but in most climates Iris do best in full sun.

Prepare the soil: Bearded Iris prefer well-drained soil. Amend heavy soils with Gypsum or other soil conditioners to improve drainage. Planting on a slight slope or in raised beds ensures that the Bearded Iris will not stand in water. In terms of pH, the ideal is 6.8 or slightly acidic. Have your soil analyzed before you take corrective measures regarding pH.

Remove all weeds from the area to be planted, and then cultivate the top 12 inches of the soil in your beds for ease of setting the rhizomes and ensuring proper drainage. Nearly fill a wheelbarrow with one part sand to two parts organic material, such as well-aged garden compost, composted manure, and/or leaf mold, and mix thoroughly. To this add a good balanced-nutrient fertilizer, low in Nitrogen, such as our very own Controlled Release Iris Food. Turn this mixture back into the cultivated soil.

Planting: Iris need to be planted so that the tops of the rhizomes are exposed and roots are spread out facing downward in the soil. Recommended distance to plant rhizomes is 12” to 24” apart.

Good things come in threes, and fives….Make a colorful impact by planting a single variety in threes or fives — an age-old gardening custom that remains true in modern gardens everywhere. Consider the number of rhizomes you’ll be putting in as you prepare your Iris beds. Visit our Online Catalog and Summer Sale to shop multiples of your favorites.

Author: Schreiner's Iris Gardens

Growing beauty since 1925. Retail and wholesale supplier of high-quality Bearded Iris & Daylilies.

21 thoughts on “Preparation for Planting

  1. I have a very sandy black soil. I want to plant a lovely bed of Iris. I have dug and raked through blood and bone. I also make a garden tea fertiliser that I use during flowering and after flowering. Is there anything else I could do. Is it ok to lay mulch around the plants?

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  2. I split a large clump and replanted them, late August in Maine. How much of your 6-10-10 fertilizer per plant should I use.
    Thank you, Barbara

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    • Thank you for the question, Barbara. Per our package instructions, we recommend applying 1/2 to 1 tablespoon per rhizome. Work the fertilizer into the surface of the soil around the plant and then water in well. Apply one month before bloom, and again approximately one month after the last blooms have faded. Superphosphate or bone meal are excellent soil supplements to apply at the time of planting as well.

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  3. I just planted the new Iris I purchased from you. Do I still trim the leaves to 6 inches on the new plants in the late fall? Each plant is growing nicely and getting 1-2 leaves.

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    • Hello! Thank you for the question. No, you do not need to trim the foliage of those Iris you received from us. If you have existing Iris in your garden, leave the foliage until late fall before trimming. Allow the foliage to work as long as it can at collecting nutrients that build rhizome mass and feed bloom production next spring.

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  4. I am writing to ask if you might be able to show a close-up picture of a “correctly” planted rhizome. My family is on the verge of splitting because we disagree on what is the “top part of the rhizome” exactly. We understand which side it is 🙂 it’s the extent of what to leave above the ground that is the cause of confusion.
    Thanks!

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    • Hello, As a rule, it is company policy that we do not take sides in family feuds :-), but…. the IDEAL planting is that the Iris should be planted so the tops of the rhizomes are exposed and the roots are spread out facing downward in the soil. In VERY LIGHT, or loamy, soils or in extremely hot climates, covering the rhizome with 1 inch of light soil may be desirable. Firm the soil around each rhizome and then water to help settle the soil. A common mistake is to plant Iris too deeply. As to what the “top part of the rhizome” is exactly, well… it’s the top. If you were to hold the rhizome in your palm, roots facing downward, foliage upward, the top would be the rounded bumpy top of the brown “potato-like” mass. Over time, if the rhizome is planted an inch beneath the surface in light soil, the new rhizome growths will eventually push themselves up and the entire mass of plants will rest on the surface. Weather, soil heaving, etc, usually push the soil aside and plant upward. We wish you, and your entire family, happy and peaceful gardening.

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  5. I live about 50 miles north of you & wonder about watering iris this time of year. The top 3 inches are pretty dry, with a little moisture further down. I am in the process of hoeing weeds & loosening the soil around my established irises (200) What do you advise for maintenace this time of year, I am also applying a sprinkling of fertilizer at this time.

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    • Little summer watering is required in established Iris beds. Iris that are newly planted do require watering, at long and infrequent intervals, to help roots become established. You will want to water in the fertilizer once applied, however. Your current maintenance works sounds just right. Happy gardening!

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  6. When do you prune or cut back the leaves?

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  7. Excellent info, thank you!

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  8. THIS INFORMATION IS VERY HEL[FUL…I CAN HARDLY WAIT FOR NEXT SPRING.

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  9. Great information–Thank you

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    • Maybe a foot note on the plantings instructions……….keep in mind instructions may vary slightly in different areas. Reblooming Irises may need more water and dividing more often depending on the area of the country. Many rebloomers must have water every ten days or they will not rebloom.

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      • Thank you for the information, Shirley. It’s always great to collect more information on rebloomers. Indeed, remontancy is greatly affected by regional/geographic conditions. Not all varieties of rebloomers will rebloom in all areas. Happy gardening!

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  10. If iris bulbs are slightly covered with soil and have not bloomed for a few years, are they likely to bloom if replanted with the surface above the soil level?

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    • Iris do prefer a shallow planting. Lack of bloom can be the result of a combination of factors, though. Before replanting the rhizomes, be sure to cultivate and nourish the soil so that the rhizomes have good drainage and sufficient nutrients. Also, choose a site that provides adequate sun each day. Check that the rhizomes are firm and free of any rot before replanting.

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  11. I replanted alot of my Iries last year, but some didn’t blooms this year. The white part of the plants is showing, so I don’t think I planted to deep. Not a very cold winter. Now that it is hot, when would be the best time to cut back the leaves, they are really getting dry out with the hot weather we have had? What shoud I use on them for winter? I have them planted in rolls about 1 to 2 feet rolls and about 6 to 8 inches apart. REally made them big , to get my culivator down the rolls.

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    • We recommend waiting until the end of summer/early fall before you trim the Iris leaves. They are still collecting essential nutrients for the rhizomes. If any of the foliage is affected by leaf spot, you may wish to trim only those leaves to just below the affected area. Otherwise, leave the foliage as directed above.

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