Iris is a beautiful and iconic flower that can add a pop of color to any garden While irises are commonly grown in flower beds, did you know they can also thrive when planted in pots? Growing iris in containers opens up new possibilities to showcase these gorgeous blooms on patios, porches, and small spaces
In this complete guide, we’ll cover everything you need to know about successfully growing iris in pots
Overview of Growing Iris in Containers
Iris can be grown in containers as long as a few key needs are met. Here’s a quick overview:
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Pot Size: Use a pot that is at least 12 inches wide and deep. This gives iris enough room for the rhizomes and roots.
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Soil: Iris need well-draining soil. Aim for a mix that contains compost, sand, and peat moss.
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Sun: Iris require full sun for at least 6 hours per day.
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Water: Water deeply but infrequently. Allow the soil to dry out between waterings.
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Fertilizer: Feed iris with a balanced organic fertilizer once a month during growing season.
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Drainage: Ensure pots have drainage holes to prevent wet soil. Elevate pots off surfaces.
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Winter Care: Keep pots outdoors over winter to provide the chill iris need. Mulch for insulation.
With the right care, many types of bearded iris can thrive in containers. Let’s look at how to grow them successfully.
Choosing the Best Iris for Pots
There are a few key factors to consider when selecting iris varieties that are suitable for container growing:
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Type: Go with dwarfed or mini bearded iris. Standard bearded iris can work but require more space.
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Mature Size: Pick more compact varieties that reach 12-24 inches tall and wide. Larger iris are difficult to manage in pots.
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Bloom Time: Early bloomers are best to maximize flowering before summer heat. Avoid very late blooming iris.
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Hardiness Zone: Select varieties suited for your zone to ensure winter survival. Zone 5-9 iris tend to do best.
Some excellent dwarf iris varieties to look for include ‘Pixie Won’, ‘Batik’, ‘Clarence’, and ‘Eric’. For standard iris, ‘Immortality’, ‘Rapture in Blue’, and ‘Bold Print’ are good container choices.
Choosing the Right Container for Iris
To grow healthy iris in pots, start with an appropriate container. Here are the key things to look for:
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Size: Choose at least a 12 inch wide pot. Bigger is better to accommodate rhizomes.
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Depth: Pots should be 12 inches deep minimum to allow for rhizome growth.
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Drainage: Ensure your pot has holes to allow excess water to drain out.
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Material: Heavy plastic, ceramic, terra cotta, and wood pots all work well.
For larger iris varieties, use at least a 16-18 inch wide container. You can also use half whiskey barrels, galvanized steel buckets, and nursery pots as long as drainage is adequate.
Avoid shallow pots or bowls. Make sure any decorative outer pot has a separate inner nursery pot. This prevents water logging.
Preparing Pots for Planting
Before planting your iris rhizomes, take a few easy steps to get your containers ready:
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Clean pots thoroughly and add drainage holes if needed.
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Place 2-3 inches of gravel, pebbles, or packing peanuts at the bottom for drainage.
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For tall pots, add a 5-7 inch layer of lightweight filler such as perlite, vermiculite or bark. This reduces soil needs.
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Mix your potting soil blend. Aim for a lightweight mix of 1/3 potting soil, 1/3 peat or coir, and 1/3 perlite or vermiculite.
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Make sure the soil is well draining and amended with compost. Check that the pH is slightly acidic, around 6.5.
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Moisten the soil before filling pots. Pots should be filled nearly to the rim to support rhizomes.
Preparing your pots properly goes a long way towards healthy plants!
How to Plant Iris Rhizomes in Pots
Once your pots are prepped, it’s time to plant. Follow these tips for success:
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Select plump, healthy rhizomes that show no signs of rot or pests. Trim any damaged roots or leaves.
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For bearded iris, choose rhizomes that have at least 3-4 leaves. Mini iris only need 2 leaves minimum.
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Plant in late summer or early fall. This gives roots time to develop before winter dormancy.
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Place rhizomes horizontally at or just below the soil surface. Don’t bury them too deeply.
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Space rhizomes 4-6 inches apart in the pot. Plant in groups of 3-5 rhizomes for best impact.
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Cover with soil so just the tops are exposed. Gently firm the soil around the rhizomes.
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Water well until soil is moist but not sodden. Allow pots to drain fully.
Proper planting technique gives your iris the best start possible. With a little care, you’ll have gorgeous flowers next year.
Caring for Iris in Pots
Caring for iris in containers takes a little extra effort but it’s very rewarding. Follow these tips for success:
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Sun: Give pots full sun daily, ideally 6 hours or more of direct light.
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Water: Water deeply as soil dries out but avoid constant moisture on leaves or rhizomes.
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Fertilizer: Use organic fertilizer every 4-6 weeks during the growing season for steady nutrients.
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Pruning: Cut back flower stalks after bloom and trim damaged leaves to keep plants tidy.
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Winter Care: Allow pots to experience winter’s chill for 6-10 weeks of temps below 45°F to stimulate reblooming. Mulch pots for insulation if needed.
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Division: Replant rhizomes every 2-3 years as plants outgrow their pots and bloom production declines.
Monitor your plants and make adjustments as needed. With attentive care, potted iris will flourish season after season.
Troubleshooting Problems with Iris in Containers
Growing iris in pots comes with a few potential challenges. Here’s how to troubleshoot common issues:
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Failure to bloom: This is often due to insufficient chill time in winter. Leave pots outdoors or place in an unheated garage over winter.
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Small blooms: This can be caused by overcrowded rhizomes or insufficient sunlight. Divide rhizomes and ensure pots get at least 6 hours of sun.
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Rotting rhizomes: Wet soil and poor drainage commonly cause rot. Allow soil to dry between waterings. Add more sand or perlite to improve drainage.
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Pests: Aphids, thrips, and borers may attack container iris. Use organic pest control methods and prune out infestations.
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Fungal issues: Leaf spots, blights, and rust are common. Improve air circulation between pots and remove affected foliage promptly.
Catching problems early allows you to take corrective action and get your potted iris back on track.
Overwintering Potted Iris
One key to success with potted iris is proper winter care. Iris need a winter dormancy period triggered by cool temperatures below 45°F for 6-10 weeks. Here are some tips to overwinter containers successfully:
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Timing: Bring pots inside in late fall once night temps are regularly in the mid 30s F.
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Location: Place pots in an unheated garage, enclosed porch, or cold frame if possible. A bright cool window also works.
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Temperatures: Shoot for temps between 33-45°F. Avoid prolonged temperatures above 50°F.
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Watering: Cut back on watering but don’t allow pots to fully dry out during winter.
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Spring Transition: Acclimate pots back outside once daytime temps are in the 50s F for a week or more.
Giving your iris pots the chill time they require will ensure prolific blooms the following season.
Dividing and Propagating Iris
Every 2-3 years, container iris will outgrow their space and need division. Here’s how:
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Dig up entire plants in early fall and wash off excess soil. Trim any dead roots or leaves.
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Carefully break apart rhizome clumps, ensuring each division has 2-3 healthy leaves and roots.
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Replant the healthiest, largest rhizomes in fresh potting mix enriched with compost.
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Smaller divisions can be replanted in pots or gifted to fellow gardeners. This is a great way to propagate iris!
Dividing overcrowded pots revitalizes plants. With proper care, newly divided rhizomes will quickly establish and reward you with bountiful blooms.
The Reward of Growing Iris in Containers
With a little effort, iris are a fabulous addition to any patio or small space garden. Their colorful, delicate blooms and sword-like foliage add striking texture and appeal. Caring for iris in pots has its challenges but the payoff is enjoying these iconic blossoms up close.
We hope these tips equip you to successfully grow potted iris. Let us know if you have any other questions! We’d love to help you enjoy thriving container iris.
Why do planting iris bulbs in the pot?
I agree with Bob that when the new irises arrive, “It’s over 90 degrees, the ground is too dry and hard to dig, and we’re leaving for a vacation trip tomorrow anyway.” So, if you live in the hot, humid South or Southwest and you bought a $45 introduction, you need to think seriously about setting that plant or any other for that matter out in the broiling heat. The alternative is to pot incoming rhizomes and to place the pots in a shady location.
The root systems developed while the irises were potted will enable the plants to remain where they were planted. Potting does reduce losses during these two susceptible seasons. If bloom is expected on first year plants, potting them and getting them established early makes bloom a sure thing. There are more reasons for potting irises than not, and growth and bloom seem to be the priorities for doing so.
The most desirable month for planting or transplanting irises in hot climates is September, when cooler temperatures make it more bearable to be outside, but it is often difficult to find a commercial source that still has blooming-size rhizomes for sale. Also, it has been my experience that when I have ordered early and requested late delivery, I have received inferior rhizomes.
I have also had cancellations or gotten substitutes when I ordered in early spring and requested late August or September delivery. Typically, September is the driest month in the South, and the thirst of newly planted rhizomes can cause an added expense by inflating the water bill. So, to ensure you get quality plants of desired varieties, order early and pot the rhizomes. The boost the rhizomes get while in pots will almost guarantee first year bloom in your garden.
How do I grow potted irises
When a box Iris rhizomes arrives, open it immediately and check the rhizomes for mold or rot. If you find any, trim it off. Also, cut or shave off all roots. Then prepare a mixture of one part liquid bleach to nine or ten parts water. Soak the rhizomes for at least thirty minutes. Allow the plants to air dry before planting.
The clorox bath is necessary to kill any rot potential that might have developed in transit and to prevent it from forming while the irises are potted. Plants may stay out of the ground indefinitely, but if a good head start is desired, the rhizomes should be planted within a day or two of receiving them.
For years at iris sales or auctions I had always seen a few irises potted in black plastic pots. I used gallon pots when I first started potting irises, for I thought I needed at least a gallon of soil for the plant to survive. I did not trim the roots, nor did I provide a bleach bath.
Most of the time I just used garden soil that became as hard as a brick when the pots dried out. At planting time it became a chore to move the heavy pots to their blooming spot and to dig a hole large enough to accommodate the contents of a gallon pot. After experimenting with a few four inch plastic pots, I have decided that they are perfect for the potting procedure. I have not found a rhizome too large to fit in one. If a rhizome has a ‘snout’, an extension of growth on the toe, cut it off and consider it to be a second rhizome and plant it in the same pot with the mother rhizome.
The potting mixture should neither be friable or compact. A happy medium consists of one-third Magic Earth (a potting soil with fertilizer), one-third garden soil, and one-third sand mixed well. No other fertilizer is necessary.
Here are several recommendations on how to plant Irises in pots:
- Place soil mixture in four inch pots up to the rim and soak with water.
- The soil may settle and more may be needed.
- Set the rootless rhizome half exposed in the soil and firm it with your fingers.
- Make sure the soil level is at the top of the pot so no water can stand in the pot.
- It would be almost impossible to place a rhizome in such a small pot if it still had the roots intact.
- New roots will form quickly and wrap around and around the soil in the pot.
- Tag or label the plant as usual.
Watering the plants may become necessary depending on the weather. It is best to water the pots from the bottom up. Add water to a level of three inches in a galvanized tub, and place the pots in the tub. Allow the water to be absorbed through the drainage holes. Remove the pots when the soil is damp.
It is important to move the pots occasionally so roots don’t find anchor through the drainage holes. A few weed seeds may sprout, but these are easily removed.
Plants may be left in the pots until October to be planted where they are to bloom. In the meantime, preparations should be made for the iris beds or rows that will accommodate the new plants when it is time to unpot, one tap with a trowel will loosen the soil and root ball. That same trowel should have been used to dig a hole about four inches deep. For an extra boost, alfalfa pellets or a balanced fertilizer might be added to the planting hole. Firm the soil around the plant and water.
In summary, many people would consider potting irises to be double trouble. It really isn’t when one considers the growth and bloom potential of the potted irises over the traditionally planted irises. Losses are almost nonexistent.
Planting Iris In Pots | Container Gardening
FAQ
Do irises grow well in containers?
Iris can be grown in containers with much success.
Can you leave irises in pots year round?
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Climate:In milder climates, irises can tolerate being in pots year-round. However, in areas with very cold winters, you might need to move them to a protected location or provide extra insulation.
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Potting Mix:Use a well-draining potting mix to prevent root rot, which is a common problem with irises in pots.
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Watering:Irises need regular watering, especially during dry periods, but avoid overwatering, which can lead to root rot.
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Sunlight:Ensure the pots receive adequate sunlight, as irises generally need at least 6 hours of sunlight per day.
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Division:Irises can become overcrowded in pots, so you may need to divide them every few years to maintain their health.
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Deadheading:Remove spent flower stalks to encourage new growth and prevent the plant from wasting energy on seed production.
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Mulching:Mulch around the pots to help retain moisture and regulate soil temperature, especially during hot or cold spells.
How do you keep potted iris alive?
Irises should be situated in a location that receives full sun. Container iris plants also require a well-draining potting mix, as the plants can easily become waterlogged. This will help to reduce the likelihood of other common issues, such as root rot.
What do you do with potted iris in the winter?
Protecting Iris in Winter
Leave the rhizome to dry overnight in a plastic crate or on a rack so that air can circulate fully around the roots. Loosely wrap the roots in newspaper and pack them in a shallow layer. Place the box in a dark, frost-free spot over the winter.
Can irises grow in a pot?
Though not traditionally considered to be a container plant, irises can grow well in a pot, provided it is large enough. Bigger pots are ideal, as many irises quickly establish robust root systems. Growing iris in a container will require special attention to the needs of the plant, specifically sunlight and watering.
When should I plant irises in pots?
The best time of year to plant iris in pots depends on the type of roots your plant has. Bulbous types bloom from late February until June in most growing zones. These irises require a period of chilling before blooming and need to be planted anytime from late September to November.
How many Irises can you plant in a pot?
“Choose a pot that is wide and shallow, rather than one which is narrow and deep,” says Simon. “Depending on how many irises you want to grow, I would recommend starting with one that is 38-44cm across and 20-26cm deep. This will allow you to plant at least five irises.
How do you grow irises in pots?
Follow these tips for successfully growing irises in pots: Plant rhizomes 1-2 inches below the soil surface with the fans visible. Place 1 rhizome per 6-8 inch pot or 3 per 12-14 inch container. Water when the top inch of soil is dry. Avoid soggy mix that can rot rhizomes.
Can I plant tall iris in a container?
Container iris plants also require a well-draining potting mix, as the plants can easily become waterlogged. This will help to reduce the likelihood of other common issues, such as root rot. Planting tall iris in a container is possible, however, making sure to properly secure or stake the plant.
Can irises grow indoors?
While irises prefer outdoor conditions, some varieties, like dwarf irises, can be grown indoors if provided with ample sunlight or grow lights and good airflow. Can iris take full sun? Yes, irises thrive in full sun and typically require at least 6 hours of direct sunlight daily to bloom their best.