Dianthus in Pots – A Comprehensive Guide
All Dianthus varieties (also known as Pinks or Carnations) thrive in pots when given the right conditions. Their drought tolerance and preference for well-draining soil make container gardening easy.
With their compact size and low-maintenance needs, Dianthus are perfect for small-space gardening in a patio or balcony.
You can create a delightful focal point by combining different Dianthus varieties in various pots, showcasing a tapestry of blooms.
Dianthus are an ideal choice for outdoor pots, offering cold-hardy options and easy mobility for more tender varieties during winter. With my Dianthus hardiness chart, find the perfect match for your climate.
Explore the possibilities of different varieties like Rock Carnation, Shrubby Pink, Anatolian Pink, and Corsican Pink, combining their unique colours and textures for a personalized and stunning arrangement. Use your creativity to create a container garden that reflects your style.
The article will guide you through the steps you need to take to grow Dianthus in pots successfully.
How to plant Dianthus in pots
In this section, we will discuss the key points you need to consider when planting a Dianthus in a pot.
Choosing a pot for a Dianthus
When you choose a pot for your dianthus, you should consider other important things besides aesthetics.
Any container that holds soil and allows water drainage at the bottom can function as a plant pot. Nonetheless, the container’s size, shape, and material are crucial in determining your potted plants’ success. These factors significantly impact water availability and insulation, influencing the overall health and growth of your plants.
The container size
The general rule is the larger the plant, the larger the container. However, Dianthus are not very large (up to 50 cm / 1.6 ft), so you do not need a big container. You can choose a vertical or horizontal container, but note that the watering needs will differ due to the different water retention associated with different container shapes.
However, growing plants in containers will not reach the same size as when grown in the ground. Pots limit the growth of roots and, therefore, the size of plants.
Basically, the container needs to be big enough to provide room for the roots, hold the necessary water for the plant, protect from winter temperatures, and be stable not to tip over.
If your pot is too small:
- The Dianthus will become rootbound, and growth will be stunted.
- The soil will dry out quickly.
- It will be more exposed to winter temperatures.
- It may fall over easily because the pot is unstable for too big of a plant.
If your pot is too large:
- The soil will stay wet for too long because the roots will not be able to absorb water from all the soil. This will cause the roots to stay damp and possibly rot.
Aesthetically the size is also important. There needs to be a balance. A common design rule is the container should be about half the height of the plant. But in the end, it is really up to your taste, of what looks more pleasing to you.
Upsizing
I suggest you choose the size of your pot based on the size of the pot where the Dianthus is currently in. As a general rule of thumb, you should upsize 5 – 10 cm (2 – 4 inches) in diameter. This will allow extra room for growth as the Dianthus matures.
The plant will be better off if you change the size of the pot as it grows, instead of planting it in a large pot right away.
Your Dianthus will give you 2 important signs that it needs to be repotted, such as:
- It needs to be watered more frequently
- The roots start growing out of the drainage holes.
Generally, the Dianthus will need to be transplanted once every two years until it grows to mature size. Nevertheless, keep an eye on it for the signs.
Repotting
The best time to change your Dianthus to a new pot is during the spring.
Make sure the container is larger than the current one, has sufficient drainage holes and has good-quality soil.
Remove the Dianthus from the current pot, loosen its roots and then place it into the new container. Cover the roots leaving some space below the rim to allow room for watering. Finally, water it thoroughly.
The Container Shape
When choosing the shape of your container, you should consider not only its ornamental characteristics but also its stability and water retention.
Stability
The shape of the container determines if it´s stable enough to keep the plant from falling over with the wind. This becomes particularly crucial when dealing with tall and dense plants.
Square and rectangular pots are the most stable. Then come the cylinder pots. Finally, the least stable ones are the more traditional inverted cones which tend to tip over easily.
Water Retention
The shape of the container affects the water retention capacity. Even when containers have the same volume and potting mix, water will dry out faster in a tall, narrow container than in a short, wide one.
This is due to the perched water table, which will be at the same height regardless of the shape and size of the pot.
The image shows two pots with the same volume and potting mix and, therefore, the same perched water table height.
As you may see, the tall, narrow pot holds less water than the short, wider pot. Also, the water is further away from the roots in the taller pot.
So with this in mind, and knowing that Dianthus plants have quite deep roots (they are found growing in rock crevices which require deep roots to reach the underlying soil) and need good drainage, you will choose a pot that is preferably tall and narrow. If you prefer a more horizontal pot, you need to water it less and more frequently to avoid too much water retention near the roots.
The container material
The material that the pot is made of should also be considered when selecting a pot for your Dianthus. Different materials include Plastic, Metal, Cast cement, Terracotta, Glazed clay, Wood, and many more.
The material has a significant impact on the drainage of the soil and the insulation of the roots.
Soil Drainage
Pots made of plastic, metal and glazed pots will resist water loss and keep the soil moist for longer.
Pots made of porous material such as terracotta or wood will soak water from the soil and release it easily, enabling quick soil drainage.
For your Dianthus, which prefers dry and well-aerated soil, you will want to choose a pot with a more porous material such as terracotta or wood.
Insulation
The temperature of pots with a porous material such as terracotta and wood will not fluctuate as much as plastic or metal materials. Therefore the porous material is a better option to insulate the roots from extreme temperature fluctuations.
However, during winter, terracotta pots can break easily in freezing temperatures. This is because water can get into the pores and expand when it freezes, causing the pot to crack. To prevent this, you can wrap the terracotta pot with plastic to keep it dry and avoid potential damage.
The best soil for Dianthus in pots
Drought tolerant plants, such as Dianthus, need well-aerated soil with good drainage. Soggy soil is a real problem for them.
If you want a happy Pink (Dianthus), you must imitate its natural environment as well as possible, starting with the soil.
The potting medium for your Dianthus should have the following characteristics:
- Well aerated
- Good drainage
- Hold on to nutrients
- Retain some moisture
Various recipes exist for potting mixes, but when caring for drought-tolerant plants like Dianthus, it’s essential to increase the amount of large-particle ingredients, such as coarse sand, vermiculite, or perlite. This step ensures the potting mix maintains excellent drainage and aeration, supporting the health of your Dianthus plants.
The image shows how the amendment with a large particle-sized ingredient (ex: coarse sand, vermiculite or perlite) affects the soil’s drainage.
How to care for Dianthus in pots
If we plan to grow Dianthus in containers, we must not forget that plants in containers are more susceptible to the dryness of the soil, the effect of extreme temperatures and the inaccessibility to nutrients.
Dianthus are tough plants and tolerate harsh environments. However, they still need special attention when grown in containers.
Because containers have a limited quantity of soil, watering and fertilizing become necessary, even for established Dianthus. Additionally, the roots in a container are more exposed to temperature fluctuations, so care must be taken to protect the roots.
How often to water Dianthus in pots
Even though Dianthus plants are drought-tolerant and do not need to be watered once they are established, this is not the case when they are grown in containers.
How often you need to water your Dianthus will vary depending on the weather, the potting soil, the type of container, and the exposure of the container to sun and wind.
- Weather: During the winter, the plant will need much less water because it is not actively growing and is not as hot.
- Soil: If your potting soil does not drain easily, you must water it less frequently than if it has excellent drainage.
- Pot material: If your pot is made of a porous material, you will need to water it more frequently than if it’s made of plastic or a glazed material.
- Pot size: If the pot is smaller, it will need more watering than if it´s larger.
- Exposure: If your plant is exposed to many hours of sun and winds, it will need more frequent watering than if it has some shade and is sheltered.
This means there is no universal watering schedule for your plant. So you will need to observe your Dianthus regularly to determine when it requires watering.
How to check if your Dianthus needs water
You should not wait for the plant to show severe signs of wilting due to insufficient water or die from excess moisture.
The easiest way to know if the plant needs water or has excessive moisture is to stick your finger in the soil and feel how dry or moist it is.
In the case of sandy soils, which are the best for these plants, I do not recommend using a moisture meter because even when the soil is moist, the probe cannot detect the moisture accurately due to the air pockets in this large particle soil. So the reading will always be “dry soil”, and you will inevitably overwater your plant.
How to water your potted Dianthus
In the case of drought-tolerant plants like Dianthus, you will need to let the soil dry out completely before watering again. The rule is to water deeply and infrequently.
When you notice the soil is dry, it is time to give it a deep watering. You must wet the soil thoroughly until water drips out of the drainage holes.
After this, let it be until the soil has dried out again. You may be surprised by how long your Dianthus can go without water. You are better off giving it less water than overwatering.
If you notice a gap between the soil and the pot, then you should press the soil against the pot’s wall to close this gap. Otherwise, the water will flow right out through the gap. This is more common when you have just potted your plant, and the soil is not yet tightly pressed.
Finally, you may want to cover the soil with some mulch, ideally gravel, to help conserve moisture. This will also give some extra protection from the cold temperatures of the winter months.
Overwintering Dianthus in Pots
Plants in pots are less hardy compared to those in the ground. The plant’s above-ground parts are hardier than the roots. When the roots are inside a container, they become more vulnerable to cold temperatures because they are more exposed to the cold air.
Plants in pots are also more prone to freezing and thaw cycles. If your plant is in a sunny spot, as Dianthus should be, it can warm up considerably during the day and freeze at night, which is very hard on the root system.
So to minimize the problems, I have the following tips:
- Choose a Dianthus that is more cold-hardy than your zone ( generally 2 zones under).
- Plant in a large container (but always matching the size of the plant). The larger the pot, the more insulation it will have around the root system.
- If the pots are not too heavy, move them into a cold frame, a shed or a more sheltered location outside and cuddle several pots together.
- Dig a hole in the ground, place the pot inside and cover it to the brim.
- Wrap the pot with a thick burlap, bubble wrap or straw layer.
Don´t forget to give your plant a deep watering at the end of the season and then keep an eye on it during the winter and water it when needed.
Usually, Dianthus will not need watering in the winter. Still, when they are in containers, they may need to be watered not to let the roots dry out which can easily happen in a container because of the limited quantity of soil.
Fertilizing Dianthus in pots
Dianthus plants prefer poor soils. However, when they are in pots with a limited amount of soil, they consume all the available nutrients after a certain period.
So it is necessary to give them some fertilizer from time to time, to replace the nutrients.
Companion plants for Dianthus in pots
You can plant Dianthus in their own container or mix them with other plants that have the same hardiness, sunlight and water needs.
Cistus, Rosemary, Thyme, Lavender, Santolinas and Helichrysum will all go well with Dianthus plants
Considering plants that require the same conditions, you can freely choose the size, shape and colour combinations of your preference.
