Cultivation

In the spring of 1993 Bronnen started the cultivation of a number of rare species in relatively small quantities of up to 2.000 each. The different sorts included Crab apple (Malus sylvestris) , Wild pear (Pyrus pyraster), Cornelian cherry (Cornus mas), Red honeysuckle (Lonicera xylosteum), Stem elm (Ulmus laevis), Wych elm (Ulmus glabra), Buckthorn (Rhamnus catharcticus) and Barberry (Berberis vulgaris), which were cultivated as biennial plants. The largest proportion of harvested seeds and cuttings were cultivated by other nurseries.

Commissioned cultivations

Reliable nurseries are commissioned to cultivate large numbers (10.000 and more) of over fifty species, including Hornbeam (Carpinus betulus), Small-leaved and Large-leaved lime (Tilia cordata and platyphyllos), Hedgerow and Woodland hawthorn (Crataegus monogyna and laevigata), Common and Sessile oak (Quercus robur and paetraea), Spindle tree (Evonymus europaeus), Rowan ash (Sorbus aucuparia), Alder blackthorn (Rhamnus frangula), Alder (Alnus glutinosa), roses and willows on a contract basis. At the moment Bronnen has cultivation contracts with six nurseries.

Cultivation methods

The woody plants are cultivated generatively (by means of seeds) and vegetively (by means of cuttings).
Sowing is the most usual work method. It is an effective and low-cost way of multiplying stock. Some plant types can be cultivated in large numbers, providing natural seed from reliable origins can be harvested in sufficient quantities. The site of origin, time of harvest, quantity and vitality quality of the seed are registered.
Next to sowing, cuttings are the most attractive method. Multiplying by means of summer cuttings takes place in a greenhouse under moist conditions. Cuttings can provide opportunities for reproduction in situations where little seed is available. Not all woody plants are suitable for this method, however. Winter and/or summer cuttings are taken according to the type of plant.
At the nursery a number of different 'breeding corners' are set up. These can be used at a later date as seed banks and sources for cuttings.

Reliability

The reliability of the product is of prime importance in the cultivation of native woody plants. In order to provide the consumer with guaranteed reliability the following steps are undertaken:
- In order to collect reliable native plant material, high consideration is given to research and documentation in the harvesting process. Monitoring of (research) data, such as the harvest location (with the use of topographical maps), the native character of the harvested species (history of the site, age, inventory of other species present, collection of herbarium material) make it possible to trace the origins of the cultivated plant material or conduct further research;
- Bronnen harvests on these sites personally;
- Cultivation is carried out by Bronnen or by reliable nurseries.

List of native trees and shrubs