How Deep Do You Plant Iris Bulbs?

Have you placed your iris bulbs in the ground? The iris bulb is an extremely important plant in your home if you want your garden to be beautiful. If you are planting your iris bulbs, you must keep them as they were planted. You will also have to plant and water them every few get the most from your iris plants, you need to replant the bulbs in a deep, moist area so that they can survive. The best time to plant your bulbs is in the fall – early autumn. It is better to plant in the fall because the plants can still survive through winter before they put out their beautiful blooms. In this article, you will find How deep you plant Iris Bulbs? and How to plant your Iris Bulbs.

Can you plant your iris bulb too deep?

Iris bulbs and rhizomes should be planted deep, so blooms don’t die. The soil’s low temperature and wetness to maximize blooming are vital concerns. When planted too deep, the soil temperature can be too cold and cause the rhizomes to grow very slowly or not as well as stunted, formless stems. The soil becomes waterlogged, and the bulbs wither and die. The rhizomes can survive outside the soil but do not come back to life, and plants from previous years are lost.

How Deep Do You Plant Iris Bulbs?

To plant your rhizomes:

  1. Dig a hole. Your plant should be in a good location for blooming.
  2. Plant the rhizome as deep as it was originally planted.
  3. Make sure you backfill the hole with soil and keep it moist. If your plants are still new in the ground, you can transplant them to a nearby place to get more sunlight if necessary.

Some people have even trimmed off their rhizomes when they have grown out of their allotted space. Dutch Iris bulbs bloom in spring in shades of lilac, bronze, royal blue, red and yellow. However, some varieties have different colors, such as yellow, orange, and white. Plant bulbs on 4- to 6-inch holes in 4- to 6-inch deep trenches.

Can you plant your iris bulb too shallowly?

Yes. If you plant it too shallowly, the rhizomes will never grow. So make sure to plant it as deep as you have. Soil should not be more than 1/4 inch thick for the bulb to grow properly.

Growing Irises

1. Soil Type

Irises need heavy soil for blooming and are successful with grit. Adding grit to the planting hole is a good idea if the soil is heavy.

2. Soil Moisture

 Studies have proven that the depth of soil water decreases with rising temperatures. In other words, the deeper the temperature, the less moisture is available to your plants. Soil moisture should be maintained at a level between 45 to 50% of field capacity.

3. Sunlight

It’s important to know that there is a direct relation between the intensity of sunlight and the number of flowers produced on your iris plants. They should be exposed to full sun for 18 to 24 hours daily. To prevent burning, use a trellis or a wire fence.

4. Irises Bulb Planting

It is best to start these irises directly in the garden. Irises bulbs are best planted in September and October. When the weather starts to cool and encourages maintenance, remember, the sooner you plant your bulb, the better their chance of blooming in your climate zone.

5. How To Plant Iris Bulbs

Bearded iris bulbs should be planted at least 1 ft. in deep soils with enough moisture. Apart from well-drained soil. Set your bulbs in a sunny spot and water them regularly until they bloom.

How deep do you plant divided irises?

Divided iris roots are shallow, so they adapt to various soil conditions. As long as the soil they are planted in is high in organic matter and relatively well-drained, divided irises will thrive. The best way to determine the depth to which you should plant divided irises is by working with your bulbs and keeping the root system in mind.

Where should I plant my iris bulbs?

The spot you plant will be determined by many factors, such as where you want to grow your Iris, the weather in your area, and even the climate in the region. But whatever the criteria are that you are looking for, the main thing is to find a place that is sunny and well-drained. Plants need at least 8 hours of sun per day to grow well. During the day, shade is beneficial for Iris.

Should I fertilize my iris bulbs when planting?

No, do not fertilize them at the time of planting. You can feed and water the iris bulbs when you plant them. Fertilization for divided iris is given in spring; again, fertilizer is better in fall and spring. Divide your fertilizer into two doses and spread them in the soil before planting.

Caring For Irises Bulbs:

Like any other plant, irises also require care and attention. This is precisely where the “trick” I refer to above comes into play. Irises will grow well in most regions of the United States. With proper care and watering. However, you should have no problem growing iris bulbs no matter which region you live in.


Mulch the bulbs each spring to prevent rot. Remove all drying foliage from the bulbs after winter.


Irises require a relatively large amount of water to sustain healthy growth. It is recommended to water your bulb every 2 to 3 weeks during the growing season as long as they are at least half-grown. During the dormant season, do not water.


It is important to deadhead your Iris bulbs to encourage adventitious buds and blooms. Remove all spent flowers and remove any shoots below the outermost leaves.

Lifting And Storing

You can lift your plants and store them in a cool, dry place at any point during the season. You may also bring them indoors after nightfall or in spring if temperatures are cool. Place your bulbs in a dark, well-ventilated space, as they require little air circulation.

Types of Irises:

1.Crested Iris (Iris cristata)

Crested irises are grown in the United States, Canada, and Europe. They have a very decorative flower shape. The flowers of these plants also tend to be more fragrant and colorful than other iris varieties. They come in various colors, such as white, yellow, orange, and red.

2. Bearded Iris

This variety of Iris is often used in gardens because it flowers earlier in the year than other varieties of Iris. It is also a very popular indoor plant. It is a perennial plant. It produces flowers that are white, purple, or blue. The flower shape of bearded irises is also very interesting.

3. Australian Iris (Iris australis)

The Australian iris species is a perennial plant that comes in shades of blue and rich green. The flowers of this plant are very close to the other species of Iris but feature a large flower head that is often called an ‘umbrella.’ These irises are also available in white, yellow, or orange.

4.Iris cristata (crested iris)

This Iris is a hybrid species but varies greatly from the other Iris species. The flowers of the iris look like little plumes and are very decorative. The flower head of this variety is made up of many small flowers that open at once. They also produce a strong smell.

5. Beardless of Iris

The Iris, commonly called “Beardless Iris,” has extremely variable flowers, which can be white, blue, or purple. The petals of the flower are very large and soft. This flower is an herbaceous perennial plant.

Planting companions for iris bulbs:

Planting companions for iris bulbs include plants of similar or shorter growing heights. Select plants that don’t spread. Iris bulbs are fairly easy to grow but do not require much attention or minimal care. Irises are relatively long-lived plants, so they can sit in the soil until they produce flowers. When planting a new iris bulb, dig a hole that is the same diameter or slightly smaller than the bulb itself. Use a pencil and gently push it into the ground, so it is upright and not curled. Water the planted iris bulb well, but only when you plan on planting it to allow good root development, and avoid overwatering, as this can kill a young iris plant.

Common Issues with Iris Bulbs:

  • 1. Aphids
  • 2. Root Rot
  • 3. Iris Borers


What month do you plant iris bulbs?

Iris are planted in the spring and flowers in September. Plant in warm soil in full sun; they like moist soil and water but don’t overwater. Iris bulbs should be planted at about one inch and barely covered by the earth. The pruning blade of an old spade works as well for this task as does a pencil.

How deep do iris bulbs need to be planted?

Iris bulbs should be planted 1 inch deep and water well. The soil around the bulb should be moist but not soggy. Keep the soil evenly moist until the bulbs bloom.

How long do iris bulbs take to grow?

Iris bulbs take 4 to 5 years to bloom and fully bloom for 3-4 weeks. They are a perennial in zones 7-9 and can be divided every 2 or 3 years. Plant in spring or fall, depending on your climate.


Iris and other members of the Iris family are a great addition to your garden. The unique beauty of the Iris will leave a lasting impression, both in your garden and on guests who visit. Growing iris bulbs can be quite easy; however, it is recommended that you consult a professional at least once before planting to make sure they are planted properly. I hope you like the article. If you have any questions, please feel free to comment below.