Lomandra, a hardy and versatile Australian native plant, has gained popularity in home gardens and professional landscapes due to its robust nature and aesthetic appeal.
Landscaping around trees is both an art and a science, merging aesthetics with botany and ecology to create spaces that not only enhance property value but also promote biodiversity and improve soil health.
This guide will provide you with the knowledge and techniques to successfully navigate this process, without harming your beautiful established trees.
Landscaping Around and Under Trees
One of the most important aspects of landscaping around and under a tree is the preservation of its health. Trees, like any other living organism, require certain conditions to thrive. Disruption to their environment, such as the introduction of new plants or changes to the soil, can potentially harm them.
Therefore, it’s crucial to understand the specific needs and characteristics of your tree before starting.
Understanding the tree’s root system is a big part of this. The tree’s roots can extend a considerable distance from the trunk, often well beyond the tree’s canopy, contrary to popular opinion. These roots are crucial for the tree’s survival, providing stability, water, and nutrients. Any landscaping work must take into account the extent and depth of these roots to avoid causing damage.
It’s also important to understand that different tree species have different requirements and tolerances. Some trees may be more resilient and able to cope with changes to their environment, while others may be more sensitive. Knowing the species of your tree will help guide your plant selection and landscaping techniques.
Preparing for Landscaping Around Trees
Before starting any landscaping project, preparation is key. This involves assessing the tree’s health, choosing suitable plants, and creating the perfect soil environment.
Assessing the Tree’s Health
Before you begin landscaping, you need to ensure that your tree’s healthy. This is because a weak or diseased tree may not withstand the changes in its environment that landscaping can bring.
Signs of a healthy tree include vibrant leaf colour, firm and undamaged bark, plenty of foliage (unless it’s a deciduous tree in winter), and no signs of pests or diseases. If your tree shows signs of poor health, it may be best to consult with an arborist before proceeding.
Creating the Perfect Soil Environment
Promoting the perfect soil environment is critical for the successful establishment of new plants under your tree. This involves testing the soil pH to ensure it falls within the optimal range for your chosen plants.
Depending on your soil structure, it may need improving. Heavy and compacted clays may require gypsum and compost to break apart and improve drainage. Meanwhile, loose sandy soils may benefit from compost as well as a quality hydrogel like TerraCottem.
This will help keep moisture in the soil and prevent hydrophobicity, which is when water can’t penetrate the top layer of soil, a condition that sand-dominant soils often suffer from. However, it’s essential to do this carefully to avoid damaging the tree’s roots. Using a hand trowel or air spade can help minimise disturbance to the tree’s root system.
Choosing Suitable Plants
Choosing the right plants to accompany your tree involves considering the soil type, shade and root competition under trees. Not all plants can thrive in these conditions. Another consideration is the plant’s “genetic destiny.” How big is your plant going to get once it matures?
The following plants all have a defined height that they’ll grow to, so you don’t have to worry about the two plants rubbing on each other’s branches.
- Tanika® Lomandra longifolia ‘LM300’ PBR: This hardy plant is a low maintenance option that’s drought resistant and able to grow in a variety of soil types, making it ideal for areas under trees where soil conditions can vary.
- Little Jess™ Dianella caerulea ‘DCMP01’ PBR: A compact plant with striking blue-purple flowers that thrives in shaded environments, making it a great choice for under-tree planting.
- Blush™ Nandina domestica ‘AKA’ PBR: This dwarf Nandina is a compact, low growing plant that provides year-round interest with its changing foliage colours. It’s tolerant of a wide range of conditions, including shade, and it’s 20% smaller than Nandina domestica ‘Nana’, making it suitable for planting under trees.
- Isabella® Liriope muscari ‘LIRF’ PBR: An excellent ground cover plant, Isabella Liriope has compact, dark green leaves and produces pink flower spikes. It’s able to tolerate from full sun to 90% shade and is an ideal choice for adding texture and interest to the area under trees. It only grows to 40cm in full flower, so it’s perfect under the smallest of trees.
- ‘Gold Velvet’ Anigozanthos hybrid PBR: Although this kangaroo paw prefers full sun, it can tolerate partial shade, making it a potential choice for areas under trees that receive some sunlight. Its unique, gold velvet flowers can add an interesting visual element to your landscape.
Techniques on How to Landscape Under Trees
Mulching around trees offers numerous benefits, including conserving soil moisture, suppressing weeds, and protecting tree roots. To mulch properly, start by clearing the area around the tree of grass and weeds. Spread a layer of mulch 5-10cm thick, ensuring you leave a mulch-free area around the tree trunk to prevent rot and disease.
Remember, too much mulch can cause fungal issues, especially when piled against the tree’s base. We want stems in the air, and roots in the ground. Your tree should show a “root flare” at the base, instead of looking like a telephone pole which is consistently straight from the ground.
When planting under trees, care must be taken not to damage the tree roots. Begin by gently digging a hole as deep as the root ball of your new plant and twice as wide. Position the plant in the hole, ensuring the top of the root ball is level with the ground surface. Backfill the hole with soil and water thoroughly.
Watering and Maintenance
Watering plants under trees requires consideration of both the trees’ and the plants’ water needs. While the new plants are freshly planted, they’ll need consistent watering to establish. Once they’re established, water deeply but infrequently, allowing the water to reach the tree roots and encouraging deep root growth.
Regular maintenance tasks like pruning and feeding are also crucial to keep your plants healthy. Mulch should be checked every few years and replaced when it’s started to decompose to maintain its benefits.
Common Mistakes to Avoid When Landscaping Around Trees
Common mistakes in tree landscaping include planting too close to the tree trunk, choosing incompatible plants, and neglecting ongoing care. Planting too close to the tree trunk can cause damage to the tree and the plants, while incompatible plants may struggle to thrive due to differing light and water needs.
Regular care of your landscaped area is necessary for the health and beauty of your garden. A common oversight in tree landscaping is failing to separate the grass from the tree trunk. This makes it easy to inadvertently damage the bark with whipper snippers or brush cutters.
Damaging the bark, especially ring barking, can severely harm or even kill a tree because it disrupts the tree’s ability to transport nutrients.
Successful tree landscaping requires careful planning and execution, taking into account the health of the tree and the choice of suitable plants. Proper techniques for mulching, planting, and maintenance are crucial to create a thriving and beautiful landscape around your trees.
While it may seem challenging, remember to enjoy the process and look forward to the rewards of a beautifully, healthy tree that will thrive well into the future.