It’s not always easy to provide your plants with enough soil depth and space, especially if you have a small area to plant them. That’s why plants that have shallow roots are beneficial.
But there are things to know about them before you plant them in your garden. This article explores why they’re practical and provides a list of shallow-root plants that you can grow in the city.
Why Are Shallow Root Plants So Practical?
Growing shallow root plants in your home is great because they don’t require a lot of resources, such as soil and space. These plants have adapted to their environment. Their shallow root systems enable them to make the most of rainfall because they’re closer to the ground’s surface.
Similarly, if they grow in areas where the soil isn’t nourishing or it’s too dense, they can still access as much nutrition as is in the soil without having to spread their roots deeper into the ground. If they grow in rocky areas, their roots will be obstructed, but because the roots are shallow, they will be able to survive.
Advantages and Disadvantages of Shallow Root Plants
There are pros and cons of growing shallow root plants, both outdoors and indoors. Here are some to consider.
Pros
- They can be grown in containers or pots with shallow soil because their root systems grow laterally.
- The roots absorb water and nutrients faster from the soil, which helps the plants to thrive.
- Shallow roots make it easier to water your plants as they’re closer to the surface, and therefore water is more accessible to them.
Cons
- The plant’s roots are closer to the soil surface, which can be problematic for nearby structures, such as driveways.
- These plants don’t have a lot of stability, such as during harsh winds or rain.
Growing Shallow-Root Plants in Hydroponics: Does It Work?
Growing plants in a hydroponics system that makes use of water instead of soil as the growing medium is a great way to use fewer resources and make the most of your limited space.
Shallow-root plant systems are ideal for hydroponics because they don’t require a lot of maintenance. As long as you regularly change the nutrient solution in the water, you’ll ensure your plants get what they need to grow.
These plants can also grow shorter than deeper-root plants, which makes them space-savers, but this isn’t always the case. So, you have to think carefully when choosing plants for your hydroponics system.
Although plants with shallow root systems can grow to a shorter height than plants containing deeper roots, this isn’t always true because the size of a plant’s roots isn’t the only factor that affects the height of a plant. Other contributing factors include how many nutrients it can access in its environment and its genetics.
6 Shallow Root Plants For Urban Environments
Growing shallow root plants outdoors is beneficial because they make the most of the water and nutrients they have without needing too much of either.
With this in mind, here are some of the best shallow root plants to grow in your urban garden.
1. Arugula
Sometimes referred to as ‘Rocket,’ Arugula is a cruciferous vegetable that’s in the same family as broccoli. Its roots grow to around 14 inches (35.56cm) in length.
Although it’s easy to grow, it needs to be planted in well-draining soil, but you shouldn’t let the soil dry out between waterings. Its shallow roots dry out quickly, so you want to keep topping up its water.
Arugula needs evenly moist soil in the summer as this prevents the plant from bolting. “Bolting” is when the plant rushes through its growth stages and produces seeds and flowers without first growing leaves.
2. Broccoli
Broccoli is a vegetable that has shallow roots as they only reach a depth in the soil of between 12 to 18 inches (30.48-45.72cm). Broccoli grows vertically, and when it reaches maturity, it can grow up to about 36 inches (91.44cm) in height.
Make sure you plant broccoli in an area of the garden where it will get lots of sunlight and have well-draining soil.
If you’re growing broccoli in containers in the garden, you should be careful not to overcrowd your veggies. They can suffer from being planted too closely together, as overcrowding can cause growth issues.
3. Cabbage
Cabbage plants require about one inch (2.54cm) of water every week unless your region has experienced recent rainfall. Cabbage roots are shallow, so you don’t want them to dry out. Make sure you grow cabbage in an area of the garden that has well-draining soil.
Cabbage grows roots to a soil depth of approximately 18-36 inches (45.72-91.44cm). This is quite a lot shorter than other types of produce that can reach a depth of 48 inches (121.92cm).
You should provide your cabbage with greater nourishment by adding mulch around its base. This maintains a moist, cool soil for the cabbage to grow. Mulch also prevents pests from attacking the cabbage.
4. Hydrangeas
Hydrangeas are beautiful flowering plants that bloom in pink or blue flowers. These plants want lots of regular water and sun, although they should be protected from the harsh afternoon sun that can burn their leaves and dehydrate them.
Hydrangeas have shallow roots that grow a few inches (approximately 7cm) into the soil, so you should apply mulch around them to ensure they can maintain the moisture they need to grow and bloom.
Although they have a shallow root system, hydrangeas don’t typically require fertilizer as they grow well in a range of soils.
5. Hostas
Hostas are flowering plants with a wide variety of leaf colors and shapes. They have roots that spread out horizontally, generally within the top seven or eight inches (17.78-20.32cm) of soil. You want to ensure you plant hostas in well-draining soil filled with nutrients.
When planting hostas, you should dig a hole in the garden to double the depth and width of the plant’s root ball. You should loosen the soil around the plant as this will encourage its roots to move outward from the plant.
Although hostas do well in the sunshine, they thrive in filtered sun. This helps their variegated leaves to display their beautiful colors.
Layering a few inches (approximately 7cm) of compost around the hostas every spring encourages their healthy growth.
6. Azaleas
These flowering plants have shallow roots, so when you plant them in a pot, you don’t want to choose one, that’s too deep. The soil should be about 12-18 inches (30.48-45.72cm) deep to give your azaleas enough nutrients and water.
Even though azaleas have shallow roots, when digging a hole for your azaleas, you want to ensure that it’s twice the depth and width of their root balls.
6 Indoor Shallow Root Plants For Small Spaces
If you live in a small house or apartment, you can make use of indoor gardening, even if that means growing produce and flowers on a balcony or a small area of the home. Some of the best shallow root plants include the following.
1. Spinach
This annual crop grows shallow roots because of its short harvesting time. This is why it’s uncommon for homegrown spinach to develop its long taproot, evident in plants grown naturally. Since its roots move closer to the soil surface to reach for water, you should water your spinach regularly.
Spinach is excellent for outdoor and container gardening because it only requires approximately four to six inches (10.16-15.24cm) of soil in order to grow healthy. You can even grow its seeds in mason jars!
2. Kale
This is a fantastic green veggie to grow in containers and will provide tasty kale throughout the year. It’s low-maintenance, so it’s great for gardening beginners.
Kale has a medium root system, so you should plant it in soil that’s about 12 inches (30.48cm) deep.
However, make sure that you give your kale a lot of sun. Position it in front of the sunniest window of the home. If the temperature in your home gets hotter than 70°F (21°C), you should give your kale plants a bit of shade so that it doesn’t burn.
If your home doesn’t have enough sunlight, you should invest in grow lights to supplement it.
3. Lettuce
Lettuce grows roots to different lengths depending on where it’s grown. For example, if you grow lettuce in compacted soil, it will reach about six inches (15.24cm), whereas growing lettuce in loose, aerated soil will allow its roots to grow up to around 20 inches (50.8cm).
When growing lettuce in pots indoors, you should ensure you give it about six hours of sunlight every day. It only needs about six inches (15.24cm) of soil in its pot so that you can grow it in a shallower and longer pot. This also gives you the opportunity to increase your planting surface area when growing produce indoors.
4. Petunias
Petunias are ideal for growing indoors and outdoors, but they need full-sun conditions. You should water them regularly because their roots are shallow and only reach a depth of about five inches (12.7cm).
Watering petunias is especially important if you’re growing them outdoors in containers, such as on a patio or balcony. Depending on how much sun your petunias get, you might have to water them daily.
Instead of watering petunias sparingly, give them a thorough watering so that their roots can soak up the water. If you don’t water them enough, the roots will become shorter, and this can cause the plant to fail to grow.
To encourage their growth, you should feed your petunias with a balanced fertilizer that has a N-P-K (Nitrogen, Phosphorus, Potassium) ratio of 1-1-1.
5. Zinnias
Zinnias are flowering plants with varying root growth depending on their variety. These flowers have shallow roots that grow to between 12 and 24 inches (30.48-60.96cm) because they only live for one year, so they don’t have time to produce larger roots.
Zinnias, which look a bit like daisies, need one inch (2.54cm) of water every week to encourage them to bloom. Be sure that you don’t overcrowd them because then their roots won’t be able to spread through the soil.
You should fertilize zinnias so that you increase their flower production and overall growth. Use an all-purpose fertilizer that has the exact amounts of nitrogen, potassium, and phosphorus when first planting the zinnias.
Afterward, feed your flowers fertilizer once a month and choose one that’s higher in phosphorus so that it will promote the growth of zinnia flowers.
6. Rhododendrons
These plants that bloom in bright, cup-shaped flowers have shallow roots, so you don’t want to plant them in soil that’s too deep. Ideally, it should be less than three inches (7.62cm) deep. This allows the plants to draw enough nutrients and water from the surrounding soil.
To care for rhododendrons, make sure you water them during the hot months when there hasn’t been rainfall in your region. To maintain enough moisture, apply a two-inch (5.08cm) layer of mulch to their soil, such as pine needles or shredded pine bark.
Since these plants want well-draining soil, you can add some hydroton pebbles to your potted soil so that your flowers won’t be sitting in soggy soil.
Conclusion
You don’t need a lot of space to grow some of your favorite produce and flowering plants. Urban gardening allows you to make the most of your green fingers, but you have to know what types of plants to grow. Shallow-rooted plants that thrive in small spaces include the following:
- Lettuce
- Spinach
- Cabbage
- Hydrangeas
- Zinnias
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