How to Care for Aubrieta Deltoidea (Rock Cress)

Aubrieta Deltoidea plants are also known as the Rose Rock Cress, Rock Wall Cress, or simply the Rock Cress, belong to the Mustard family of the flowering plants. The Rock Cress plants are native to Europe but now they are grown worldwide as an ornamental plant. Their beautiful flowers create ground covers during the blooming season, making them a perfect choice to create a scenic view in your gardens or landscapes.

The Rock Cress has many varieties and 3 of them have also won the prestigious Award of Garden Merits from the Royal Society of Horticulture. They cover the whole place where they are planted. Most of the time, they are planted as the ground covers, and as a boundary of the garden. They grow fast and form a carpet of flowers in a place where they are grown.

The Rock Cress plants have oval-shaped leaves that surround the whole stem and branches. The flowers range in different colors including purple, white, and pink. The color of the flower depends on the variety that you are growing. Most of the time, experts advise growing more than one variety at the same place and time, this helps you create a multi-color ground cover. Each flower of the Rock Cress has four lavender-like petals, that spread around the central core of the flowers.

Flowers mostly appear during the spring and last till the summer, these small and beautiful flowers turn into a fruit after the flowering season. They can stick to the ground rock and grow masses of brightly colored flowers. The whole plant can only get 6 inches to 9 inches in height and 18 inches of spread. Below are the details about a few best varieties to grow.

Varieties:

Argenteovariegata:

This is one of the most grown varieties of the Rock Cress plants in the rocky areas. This variety has won many awards including the Award of Garden Merits from the Royal Horticultural Society. They are very small in size and create flowery carpets on the surface where they are planted. Their small size, easy to plant and care for nature, and beautiful flowers make them a perfect choice for your outdoor garden, landscape. You can also grow them indoors in the planters as well. They need well-draining soil, proper water supply, and nutrients to grow and thrive.

Doctor Mules: This is also an award-winning variety of the Rock Cress plants. They only grow a few inches high, but cover more area. The spread around the place quickly where they are planted. They need a full sunlight environment to thrive, but they also grow very well in bright indoor settings. They produce many flowers during the blooming season, creating a thick carpet of flowers that covers the whole space where they are grown. Keep them in bright light, provide them water and fertilizers regularly.

Red Cascade: This variety has also won the Award of Garden Merits from the Royal Horticultural Society. The flowers of this variety are red, that’s why they are named the red cascade. They also produce a cascading, or carpet-like cluster of flowers that covers the whole place where they are planted. You can plant them in any well-draining soil that contains organic matter and nutrients. Provide them bright sunlight and keep them well-fed with the fertilizers to see extraordinary flowers.

Growing Conditions and Requirements

The Rock Cress plants like to be grown under the full sun environment, they need plenty of light to properly grow and thrive. Their growth is affected when they are not receiving the proper amount of direct or indirect sunlight. Apart from the sunlight they also need plenty of water. Keep them well-watered, by regularly irrigating them. Control the speed, flow, and amount of water as they are small and fragile plants, this will protect them from overwatering and root rot.

They also need plenty of fertilizers if the soil is not good enough. You need to regularly feed them the required amount of fertilizer at regular intervals, this will help them grow and thrive and will allow them to produce more flowers during the blooming season. You can prune them as well. If you want, you can also grow them indoors in the containers. All you need to do is to keep them in a bright place where they receive plenty of direct or indirect sunlight.

Below are the details about the growing conditions and requirements:

Water Requirements

Their water needs are low, but they need water at a regular interval. You should not keep the soil moist all the time and also should not allow it to completely dry. Watering depends on many other factors as well, such as the plant’s age, height, spread, season, soil, and temperature. Keep these factors in mind while preparing the watering schedule for your Rock Cress. The small plants need water more frequently than the mature plants, also they need more water during the summer than the winter. Below are proper guidelines related to watering the Rock Cress plants based on different scenarios.

  1. As soon as you sow the seeds in the soil or plant them with division or cutting, provide them water. This water helps the seeds sprout and allows the cuttings and divisions to form roots in the soil. Keep the soil moist for most of the time unless you see the seedlings appear or cutting start forming new leaves. Once this happens, you can shift to water them according to the season.
  2. Watering the small plants once a day or two is enough, they need frequent watering but only a small amount of water should be provided to the young plants every time you give them water. This is because they only need a small amount of water and all the excess water will either drain out or cause root rot. Keep following this pattern of watering until the plants start gaining height.
  3. Once the plant is 2 to 3 inches tall and starts growing small branches and more leaves, you can start watering them once every two to three days. But every time you water the Rock Cress, you must increase the amount of water you were providing them. This increase in water will help the plant grow even faster.
  4. Watering during the summer and in the hot regions should be more frequent, you should provide them a small amount of water once every two to three days. This will help them avoid the effects of drought, and will also protect them from the root rot.
  5. While during the Winter and in the cold areas, you can reduce the watering frequency and increase the amount of water for each cycle. You should only water them once or twice every week. This frequent watering is enough for them to survive through the harsh winters.

Lighting Requirements

The Rock Cress plants like to be grown in a bright environment. They thrive under full sun environments. They also produce more flowers when they receive more sunlight. Due to this need for sunlight, and brightness, they are mostly planted in the outdoors and in the places where they receive plenty of light such as the landscapes, open gardens, and lawns, etc.

You can also grow them indoors, but you will have to keep them somewhere bright. If you have a window that opens towards the east side, that is the best place to keep them. They thrive when they receive sunlight for almost 6 hours a day. In hot areas and during the summer, you can do something to protect them, if the temperatures are extremely high.

Low light exposure creates many additional problems, most of the pests and plant diseases attack when the Rock Cress is placed indoors or under the shade for the long term.

Temperature Requirements

According to the USDA, they are hardy in regions from 4 to 8. They can survive the winter in these areas without the need for external protection. They also grow very well in the slight cold to slightly hot regions. The Rock Cress plants thrive when the temperature is between 10 F to 40 F.

The Rock Cress plants cannot survive the frost for the long term. The prolonged winter can cause them to lose all their leaves, this will result in the death of the plant. If you want to grow them in extremely cold regions, you must plant them indoors or in the greenhouses. 

Soil Requirements

The Rock Cress plants need well-draining soil to properly grow, thrive and produce more flowers. They can grow very well in clay, sandy, and loam soils. You can also grow them in slightly acidic or alkaline soils as well. The soil must be well-draining and allow the water to quickly move away from the roots. This will protect the roots of the plant.

To prepare such a soil, you can use cocopeat, organic matter, pumice, perlite, fertilizer, and sandy soil. Make sure that your soil is not contaminated. Use this type of soil to sow the seeds or plant through the cuttings. This type of soil will help the seeds quickly sprout and produce seedlings and will also enhance the growth of the plant as well.

Fertilizer Requirements

Feeding fertilizer to the Rock Cress plants is important. The soil in the rocky areas contains a limited amount of the nutrients that deplete as the plant starts growing, once these deplete, the growth of the plant halts, and you need fertilizers to boost the growth once again.

Fertilizers contain all the nutrients that are required for the proper growth of the Rock Cress, once the plants need fertilizer, they will start showing signs such as slow growth, leaves turning yellow, or flowers quickly fading away.

To overcome these problems related to nutrients and growth, you can use the fertilizers. You should be careful before applying the fertilizers. Every plant has a different type of nutrient requirement and it also depends on the soil. You should get the soil test to know which nutrients have been depleted and use the fertilizers according to the test. A soil test helps you better fertilize your plants.

There are a lot of fertilizers available to use, these include nitrogen-based fertilizers, phosphorus-based fertilizers, Calcium-based fertilizers. There are many other options as well. You should choose your fertilizer according to the soil test.

Here is how to fertilize your plants:

Three methods are recommended by the experts to fertilize your plants. Below are the details about these.

  1. The first and most used method involves spreading and mixing the fertilizer in the potting soil, or ground before the actual planting or sowing the seeds. You should do this as this helps the plant’s seeds sprout and grow quickly. It also helps the plants grow very fast at a young age. In this method, a balanced amount of all required fertilizers is taken and mixed in the soil, after that seeds are sown and water is provided to the plant. This method is useful for both indoor and out Rock Cress plants.
  2. The second method is also similar to the first one but it involves spreading the fertilizer near the stems of the plants after planting them. This method is very effective and works for both indoor and outdoor plants. All you need is to take a required amount of fertilizer that is recommended and spread this around the stem. After that, provide your plant some water. This water will help the fertilizer dissolve and become available to the plant quickly.
  3. The third method is one of the easiest ways to fertilize your plants. This requires creating a mixture of plant fertilizer and water and feeding this mixture to your plants regularly. This is an extremely useful method for small plants such as Rock Cress. The plant needs fertilizers once every month, so you can just take the mixture and pour it directly into the soil or the pot.

Be careful while fertilizing your plants. Always follow the guidelines and instructions that are provided with the fertilizer. Avoid over-fertilizing as it is harmful as well.

Pruning Requirements

The plants need pruning once the flowering season ends and flowers fade away and turn into the fruits. You can remove these dead flowers at that time. By removing these flowers, you will create a space for the new parts of the plant to grow.

Pruning is mostly done during the summer, start by cutting off all the unnecessary parts and then cut off all the dead flowers. Once you are done with the flowers, start giving a required shape to your plants.

Pests and Problems

There are a lot of pests and problems that attack the Rock Cress. These include aphids, fleas, white blister, and root rot, below are the details about these.

Aphids:

Aphids are a very common pest that attacks the Rock Cress plants as well. They are small in size but they produce a large number of offspring that can eat the whole sap of the small Rock Cress plants. They mostly attack in the damp area and low light. You need to be careful and always should keep looking for these. If you see any signs of their attacks, you should use chemical spray to kill them and protect your plant.

Flea Beetles:

Flea Beetles attack the foliage of the Rock Cress plant. They create holes in the leaves as they start eating them. Their attacks can severely damage the foliage of the plants. They are black and have a red neck. You should use the chemical spray to kill them and protect your plant.

White Blister:

White Blister is a disease among the plants caused by a fungus. This fungus attacks the foliage of these plants and starts forming white blisters that appear mostly below the leaves. This is a very serious problem and sometimes leads to the death of the plant. You should keep your plants and their foliage warm and clean from the moisture. Once you see any signs of attack, use a recommended fungicide chemical spray on them.

Root Rot:

This is also a very common problem among the different varieties of the Rock Cress plants. The root rot is caused due to overwatering or overfeeding of plant fertilizer. Most of the time, this can cause the death of the plant, but if you take early control measures, you can save your plants. Control and regulate the water supply and fertilizer supply, this will help you avoid this problem.

How to Propagate?

There are three different methods of propagating Rock Cress plants. These include root ball division, stem cuttings, and seeds. To grow your plant from the root ball division, you should uproot the plant carefully and use a sharp knife to divide the root ball. After the division, you should plant them into different spots.

The cuttings method requires taking the stem cuttings from a mature plant and then keeping these cuttings in the rooting hormone for a few days. This will help the cuttings form roots, once this happens, you can start planting these cuttings into different spots. Provide them some water and allow them to grow.

Growing from Seeds:

You can also grow the Rock Cress plants from their seeds. All you need is to take a few healthy seeds, plant them in the soil, and provide them some water. Keep the soil moist until the seedlings appear. These seedlings will slowly turn into new plants over time.

Frequently Asked Questions:

Question: Can I grow the Aubrieta Deltoidea from seeds?

Answer: Yes, the Rock Cress plants can also be grown with the help of their seeds. You can grow them from the seeds by taking a few healthy seeds and sowing them in a well-draining and moist soil. Seeds will take a few days to sprout and will produce beautiful green seedlings that grow into the Rock Cress plant.

Question: Are the Rock Cress plants invasive?

Answer: In some cases, the Rock Cress plants grow on their own if they get enough space and time to grow and that’s why they are considered invasive. But in most cases, they don’t grow on their own and are not invasive. You can easily control and regulate their spread.

Question: What is the blooming season for the Rock Cress?

Answer: The Rock Cress plants bloom during the spring and produce beautiful flowers. Their bloom lasts until the arrival of the summer. In the summer these flowers turn into tiny fruits.

Question: How quickly does Aubrieta Deltoidea grow?

Answer: The Rock Cress plants or Aubrieta Deltoidea plants grow very quickly. They don’t grow in an upwards manner, but they tend to spread all around their delicate stem. They can reach up to two feet in the spread in just one year.