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Irises are a popular perennial plant delivers a beautiful display of flowers. These plants can grow in zones 3 through 10, which means they can survive temperatures that hit minimums of -40 degrees Fahrenheit (-40 degrees Celsius). If you are growing Irises, it is important to know what to do with the plants once the flowers die. This process involves deadheading your plants, and maintaining your plants until new blooms form. [1]

Method 1
Method 1 of 2:

Deadheading Irises

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  1. Deadheading is when you remove dead flower heads from a plant. This process stops seeds from growing once the flowers have faded. Producing seeds takes up a plants energy that could otherwise be put towards producing new growth. [2]
    • Deadheading also help to tidy up your garden and get rid of withered, faded flower petals. Dead iris flowers tend to turn brown very quickly and aren't very attractive.
  2. To deadhead an Iris flower, you can pinch off the spent flower using your fingertips. Alternatively, use a sharp blade to remove the flower. You need to cut off not just the dead flower petals but also the slightly swollen fat bud-like sheath the petals grow from. [3]
    • This bulb-like part of the plant is where the seeds will form.
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  3. Don't remove the entire stalk of the plant in case there are other buds that have yet to emerge and bloom. [4]
    • Some Iris flowers will fade after a day, but deadheading them can help the plant to form new blooms more quickly, so try not to cut away the whole plant.
  4. Bearded Iris may bloom at the beginning and end of summer. Wait until this second round of flowering has occurred before cutting your flowers back. Once you know the flowering season is over, you can use a sharp pair of garden cutters to remove the tough stem. However, do not cut away any green foliage that is still on the plant. [5] [6]
    • Removing the stem will help to prevent the plant from rotting, and will also help to clean up the look of your garden.
    • Once you have cut away the stem, place it in your compost. [7]
  5. You'll notice that there are some varieties of Iris that have pretty seed heads. Many gardeners leave the flowers on varieties such as Stinking iris (Iris foetidissima) and Blackberry lily (Belamcanda) to enjoy the display of seed heads. [8]
    • Just be aware that when you leave the seed heads on, the seeds may spread, causing other Irises to grow throughout your garden.
  6. Leaving the seed heads on will make it more likely that new Irises will grow in other parts of your garden. However, be aware that Irises grown from seeds may not look exactly like the original parent plant. [9]
    • You could also collect the seeds and grow them yourself. To do this, soak the seeds in water for 48 hours. Plant the seeds once they have soaked.
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Method 2
Method 2 of 2:

Caring for Your Irises

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  1. It's very important to leave the green foliage on the plant after the flowering ends. This is because the plant draws energy into its roots through the foliage, and stores this energy to help it survive the winter. [10]
    • Leave the foliage on the plant until it withers away of its own accord. It's okay to trim off any brown tips but leave as much healthy green growth as possible.
  2. Once the foliage has withered in the fall, you can cut back the foliage to about six inches from the ground. If possible, wait to do this until after the first hard frosts. [11]
    • Try to pull off the dead foliage, rather than cutting the plant if at all possible. Cutting the plant can make the it more susceptible to disease.
  3. Irises generally don't need much fertilizer. However, if the foliage isn't a green healthy color then consider giving your Irises some fertilizer after they finish blooming. [12]
    • A granular fertilizer can be gently raked into the soil around the plant. Make sure it mixes into the top few inches of soil.
    • Avoid using fertilizers that have high levels of nitrogen since they could lead to rot. [13]
  4. Dividing your Iris rhizome will boost your plant's health and performance. [14] Wait until six weeks after the plant's blooms die to divide your rhizome. To divide your Iris [15] :
    • Dig up the rhizome and cut it into four to six pieces, each with a healthy bit of leaf and root attached. Replant each rhizome so that they are about 18 inches (45.7 cm) apart.
  5. When blooming is about to begin again, give your Iris some fertilizer to help it produce healthy blooms. [16]
    • Choose a fertilizer that is low in nitrogen relative to potash (potassium) and phosphorus. Fertilizers that have high amounts of nitrogen can make Irises more prone to rot.
  6. Try to avoid putting mulch directly over your rhizomes, as this can cause them to rot. However, you can surround the plant with about two inches of mulch, so long as the rhizomes aren't buried.
    • Try to avoid using manure when mulching your Irises.
  7. While Irises are pretty independent plants, they still may need some water in very dry weather. However, try to avoid over watering these plants, as they are very prone to rot. [17]
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  • Question
    What if the plant looks like it is dying, and the leaves are falling away at the rhizomes?
    Staubinn
    Community Answer
    You should cut the stem off after all flowering is finished. Let the leaves die back naturally. The rhizomes will continue to to grow. You can divide the rhizomes if the bed appears to become too crowded. These do best when set almost on top of the soil with the roots covered.
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      Tips

      • There are some plants that especially require deadheading to stop them sowing their own seeds and invading your garden. Not all Irises will do this but varieties including the African Iris (Dietes bicolor) will sow their own seed unless you prevent this by deadheading.
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      About This Article

      Article Summary X

      To take care of an iris when its flowers die, pinch off the dead flowers with your fingertips to encourage new flowers to grow more quickly, which is called deadheading. Make sure you pinch as close to the head as possible, since removing large parts of the stalk can damage your plant. Avoid cutting the green foliage from your irises, because this is what they use to draw energy in from the sun. If the leaves appear pale, help the plant revive by raking some fertilizer into the top few inches of the soil. Once the foliage withers in the fall, cut it back to about 6 inches from the ground. When you mulch your plants, spread mulch around your irises on the soil rather than directly onto the rhizomes, since getting mulch on the rhizomes will cause them to rot. For tips on how to care for bearded irises, read on!

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        Jun 10, 2018

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