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Guided Professional Tour of Bled’s Urban plantings report
On Thursday, October 17th 2024, 25 participants joined a professional tour of Bled’s urban green spaces. The group explored the area around Športni Park Bled, guided by dr. Jan Bizjak from Infrastruktura d.o.o., responsible for the town’s landscape management. Expert insights were provided by Bernarda Strgar (perennial plant specialist and garden designer), Matjaž Mastnak (director of Arboretum Volčji Potok, dendrologist, and author), and prof. dr. Gregor Osterc (ornamental and landscape horticulture, Biotechnical Faculty, University of Ljubljana).
Choosing the Right Companions for Woody Plants
During a discussion around a small bed with a field maple (Acer campestre) at its center and impatiens beneath, the importance of selecting suitable plants under woody species was highlighted. Perennials are far better companions than annuals, which require frequent watering. Excess water at the surface can cause tree roots to grow upward, weakening the plant. Perennials, with deeper roots, improve soil structure without competing for water, supporting healthy root development of woody plants.
The discussion also emphasized matching plant selection with the right substrates. Annuals need nutrient-rich soils for rapid growth, while woody plants thrive in engineered substrates with higher mineral content, typically used for perennials. Finally, the group noted that weed-control fabrics and synthetic mulches are unsuitable for public spaces, as minimizing plastic and artificial materials benefits the environment and plant health.
Seasonal Plants for Instant Impact
Bled, as a highly touristic destination, requires plantings that create quick visual appeal. Seasonal plants are ideal in these settings because they grow rapidly and bloom quickly, providing immediate decorative value. Their use must be carefully planned to ensure healthy development and aesthetic impact, ideally combined with woody plants and perennials. Plant selection should also consider local conditions—Mediterranean species, for example, are not suited to Bled’s climate and landscape.
Choosing Disease-Resistant in Public Plantings
At the new planting near Bled Health Center, discussions focused on choosing plant varieties resistant to pests and diseases. Trials with thyme (Thymus sp.) in Bled showed that some varieties are sensitive, leading to plant dieback and unsightly brown spots. Only resistant varieties should be used in public plantings to ensure lasting visual appeal, especially since chemical treatments are avoided.
Hostas (Hosta spp.) are often eaten by slugs, but varieties with tougher leaves are less attractive to these pests. This is a common example which illustrates the importance of selecting tougher varieties that are less problematic. The same principle applies to woody plants—for example, the white willow Salix alba ‘Tristis’ by Lake Bled is much less disease-prone than other willow varieties or the species itself.
Promoting Diversity in Urban Plantings
At a monoculture planting of fountain grass (Pennisetum alopecuroides), we admired its striking autumn colors. However, species like fountain grass and Chinese silver grass (Miscanthus sinensis ) can spread rapidly by seed, so careful management is needed, which increases maintenance costs.
Public plantings should prioritize diversity—mixing different species creates visually attractive displays year-round and supports biodiversity. Modern planting guidelines emphasize resilient plants that tolerate temperature fluctuations and variable water availability without compromising appearance. We also include low-maintenance species that thrive with minimal nutrients and care, reducing fertilization needs, cutting maintenance costs, and limiting weed growth.
Roses: Use Sparingly and Choose Resistant Varieties
Bled features several rose plantings, but managing weeds can be challenging as portrayed by Jan Bizjak. Matjaž Mastnak from Arboretum Volčji Potok highlighted the importance of preparing rose beds before planting—either by using a total herbicide or by replacing the soil with weed-free substrate.
Roses should be planted in smaller areas; if multiple rose beds are desired in a touristic town such as Bled, include plantings at several locations rather than only at one the site. This helps control pests and diseases more effectively and with fewer issues. The primary purpose of rose beds is to add color for a longer summer period.
The discussion also addressed mulches. Wood chips are not recommended for rose beds, as their nitrogen demand depletes the soil, limiting nutrients for the roses. Selecting resistant varieties and careful placement ensures healthier, low-maintenance rose plantings.
The discussion on the use of mulches in rose beds was lively, specifically regarding wood chips. These are not suitable for rose beds because their mineralization requires a large amount of nitrogen, which they draw from the soil, depleting it and leaving insufficient nitrogen for the roses. Wood chips therefore compete with roses for nitrogen and are avoided.
Equally important is planting modern, disease-resistant rose varieties. In Bled, for example, the ‘Ljubljana’ variety proved very suitable, while ‘Prešeren’ is not appropriate for large, open public areas. It would also be worth considering replacing some roses with hardy perennials and ornamental grasses, creating mixed beds where roses still play the leading role, but the perennials and grasses act as companions. This approach would extend the period during which the beds remain visually attractive—by carefully selecting perennials, flowering could span from early spring to late autumn. At the same time, it would increase biodiversity and reduce maintenance costs without compromising the aesthetic appeal of the flower beds.
Native Trees Play a Key Role
Bled is home to a wide variety of tree species, many of which date back to the era of Janez Petkoš, a forester who left a lasting legacy on the town’s landscape. Most of these older trees are carefully preserved, except in cases where they are dying or pose a safety risk along walking paths. Maintaining mature trees has proven highly successful in Bled.
Native species, in particular, thrive when their natural growing conditions are respected. The areas around many trees have been thoughtfully arranged—for example, several yews have had their lower branches lifted to prevent people from using the area as informal dumping sites.
New plantings are also sometimes needed, and selecting the right species is crucial. Poor species choice often leads to problems. For example, rowan trees (Sorbus aucuparia) are already being replaced with maples (Acer sp.) in some areas, as rowans generally do not tolerate drought well under local conditions. The discussion also highlighted the limited use of conifers in public plantings. Very few conifer species are suitable for urban areas in Slovenia, with Caucasian fir (Abies nordmanniana) and Spanish fir (Abies pinsapo) being among the few that are occasionally successful.
Finally, Bled’s approach to new tree plantings is generally high-quality. Trees are planted at the correct depth and receive appropriate care during their first years, ensuring healthy establishment and long-term success.
Text by Bernarda Strgar, Matjaž Mastnak and prof. dr. Gregor Osterc
