The use of plants on balconies in the city

As a popular and excellent place for plants, balconies enable people easy access to and close contact with nature, thus forming an integral part of the urban green infrastructure. The aim of the study was to assess the use of plants on balconies of detached houses and blocks of flats in the small Polish town of Sieraków. Plants were grown on about 33% of the balconies of detached houses and on 51% of the balconies of blocks of flats. Most of the balconies were decorated with one plant species only and the plants were most frequently placed on the railing. The most popular plant species were Pelargonium peltatum (L.) L’Hér., Pelargonium zonale (L.) L’Hér. and Petunia × atkinsiana D. Don. There were no large differences between both the building types as regards to the balcony decoration.

Rice Hulls and Anaerobic Digestion Residues as Substrate Components for Potted Production of Geranium and Rose

Economic and environmental concerns limit peat use for substrate production, promoting interest in alternative materials. Hence, in this study, 16 substrates were obtained by mixing, in a factorial combination, eight substrates with different ratios of peat, rice hulls (RH), and anaerobic digestion residues (ADR) and two types of RH: whole (WRH) or ground RH (GRH). Substrates were physically and chemically characterized and then tested as potting substrates for Pelargonium peltatum ‘Ville de Paris’ and Rosa × hybrida ‘La Sevillana’ production. Physical characteristics worsened the increasing RH content. This problem was partly solved using GRH and adding ADR to the substrates. As for chemical characteristics, RH increased P and K, reducing cation exchange capacity, NO3-N, and Ca, thus causing a possible nutritional imbalance. ADR addition increased all nutrients, restoring the nutritional balance. Geranium and rose plants were negatively affected by an increasing rate of RH. In both species, the use of GRH improved the considered parameters, whereas ADR improved some parameters but only in geranium. It was possible to partly substitute peat with 33% RH, but GRH plus ADR is necessary for geranium production, and facultative for rose. The multiple regression method and principal component analysis appear to be useful tools to understand which substrate parameters, and to what extent, influence the growth of ornamental plants.

Antibacterial Activity and Cytotoxic Effect of Pelargonium peltatum (Geranium) against Streptococcus mutans and Streptococcus sanguinis

Objective. To evaluate the in vitro antibacterial and cytotoxic properties of the methanolic extract of Pelargonium peltatum (geranium) against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556). Methods. Three extracts of P. peltatum were prepared using the leaf, stem, and root. Nine independent assays were prepared for each type of extract with chlorhexidine at 0.12% as the positive control. The agar diffusion method was performed to determine the antibacterial properties of each extract. The minimum inhibitory concentration (MIC) was determined using the microdilution method, and the cytotoxicity was analyzed by means of the MTT reduction test using a MDCK cell line. Results. The root extract had the highest antibacterial effect with a mean result of (27.68 ± 0.97) mm and (30.80 ± 0.55) mm against S. mutans and S. sanguinis, respectively. The minimum inhibitory concentration for the leaf and root extracts was 250 mg/mL for S. mutans and 125 mg/mL for S. sanguinis. Cytotoxicity assays showed that both extracts had a low cytotoxicity at high concentrations. The cellular viability was highest for the root extract at 95.3% followed by the stem extract at 80.8% and finally the leaf extract with 75.4%. Conclusions. These findings show the antibacterial properties of the methanolic extracts of P. pelargonium against S. mutans and S. sanguinis. These extracts were not cytotoxic at high concentrations.

Ivy pelargonium response to media containing sewage sludge and potato pulp

In a two-year pot experiment, the effect of five growing media on the growth, flowering, decorative value of Pelargonium peltatum cv. Maxime as well as on their uptake of the nutrients and heavy metals were studied. The media were prepared from four composts (made from: sewage sludge 70% or 35%, potato pulp 35%, straw 30% or sawdust 30%) and peat in 1:1, V:V ratio. In the 1^st year of research 7-month-old composts and in the 2^nd year 18-month-old composts were used. Plants cultivated in 7-month-old composts showed better growth-related parameters, created more inflorescences and were more decorative than those cultivated in 18-month-old ones. The medium with compost consisting of 70% sewage sludge and 30% straw gave the best results. Composts application increased nutrients and heavy metals content in pelargonium leaves. Heavy metals content was definitely lower than the value considered toxic to plants.