Aroma-roots

Why this project?

Flemish farmers are actively seeking crops to broaden their crop diversification and rotation schemes in response to greening measures imposed by the EU. Rotating different crops helps prevent soil depletion and keeps diseases and pests under control.

Horseradish (Armoracia rusticana), lovage (Levisticum officinale) and angelica (Angelica archangelica) are three aromatic root crops that can be introduced as new crops within a crop rotation system. Belgium has a long-standing tradition of cultivating medicinal herbs. In the Flemish Ardennes and the Pays des Collines, a small number of growers are still active in cultivating horseradish, lovage and angelica. However, the total cultivation area of these herbs remains very limited, particularly in the Flemish Region.

Nevertheless, contract cultivation of these root crops can provide income security for growers. Both fresh plant material and extracted aromas are used in a wide range of food and non-food products. There are numerous market opportunities, and Belgian flavour and extraction companies are actively seeking high-quality, locally grown herbs.

In short, the cultivation of root crops can make an important contribution to the profitability of Flemish agricultural holdings.

However, as these are niche crops, agronomic knowledge among farmers and the availability of suitable varieties are still fairly limited. As a result, a need has been identified for both knowledge exchange among farmers and new input from international expertise and research, which can be tested on trial fields.

Target audience

Aroma-roots primarily targets the primary sector, more specifically outdoor crop growers. Both conventional, and organic farms are eligible for this regardless of farm size.

Secondly, Aroma-roots wants to address extraction companies that process the aromas from root crops into stable semi-finished products, such as essential oils.

The third category of target market is industries that process the fresh material or the aromas into a finished product. The 3 root crops can find their application in the food industry, animal feed industry, food supplement industry, beverage industry, pharmaceutical and cosmetic industry and bio crop protection industry.

With Aroma-roots, we aim to increase yield stability and profitability for the primary producer while delivering a stable quality product to processors. Through matchmaking, we connect farmers with companies so that the farmer is assured of his marketing channel with this innovative root crop and the processing companies can count on the necessary supply of quality raw materials.

Research approach and results

Aroma-roots was an agricultural (LA) project that built knowledge on the cultivation, quality and harvestability of horseradish, lovage and garden angelica, with the aim of better supporting agricultural practice in Flanders. The results demonstrate that these root crops have clear potential, but also show that further optimisation and repeated trials are required to develop robust cultivation guidelines. In addition, the project explored the potential for valorising all (by-)biomass streams generated by these crops. Knowledge sharing and exchange between researchers, growers and processors were central throughout the project.

Varieties and cultivation potential
For garden angelica, suitable seed proved to be scarce and often of variable quality. Seed viability is limited over time, meaning that growers are best advised to multiply seed themselves once a high-quality seed stock becomes available. Horseradish, which is propagated vegetatively, is mainly grown using on-farm planting material or, within the project, through exchange within the grower group. Variety and ecotype trials revealed clear differences in yield, with horseradish ranging from 10 to 20 t/ha and garden angelica from 10 to 15 t/ha. For lovage, yields between 17 and 21 t/ha were recorded. For all crops, the available dataset remains limited, and repetition over multiple seasons is required to support reliable variety selection, particularly in relation to essential oil content.

Mechanisation and cultivation technique
One of the main challenges in garden angelica cultivation is achieving uniform crop emergence. Slow and staggered germination, combined with high weed pressure, complicates direct drilling. Transplanting from a nursery bed resulted in a more uniform crop but requires additional labour. In horseradish, planting using different root sizes proved feasible: larger root pieces resulted in faster emergence, but did not lead to significantly higher yields. The choice of planting method is therefore closely linked to the available mechanisation.

Earthing up shortly after sowing or planting proved important for both horseradish and garden angelica, particularly for weed suppression and harvestability. Ridge cultivation facilitated harvesting in horseradish and resulted in higher yields in wet years, whereas for garden angelica, flat cultivation performed better under dry conditions. This highlights a clear interaction between the cultivation system and weather conditions.

Weed management
The slow early growth of these crops makes effective weed control essential. For all crops, a combination of chemical and mechanical weed management was required to achieve satisfactory results.

Harvest and quality
Different harvesting techniques were tested for garden angelica. Bed harvesters ensured complete lifting of the roots but resulted in heavily contaminated produce, while chicory harvesters delivered a cleaner product but operated at a shallower depth. With technical adaptations, further optimisation appears feasible. For horseradish, regrowth in subsequent crops remains an important point of attention.

Industry surveys indicated that, in terms of root and oil quality, purity, the absence of residues and product consistency are essential. For aromatic applications, essential oil content is the decisive quality parameter. Variety, harvest timing and storage all have a clear impact on oil content. In horseradish, the highest oil content was measured in the autumn of the first cultivation year, offering scope to reconsider crop duration. Storage leads to moisture loss and fungal development, but also to an increase in oil content, which warrants further investigation.

Economic feasibility
Based on the collected cultivation data, an economic analysis was carried out for horseradish and garden angelica. Overall, the degree of mechanisation and the final yield were found to be the main determinants of economic performance. Growers with sufficient own mechanisation can limit certain costs, while higher and more stable yields directly contribute to improved labour income. Disease and weed pressure, weather conditions and a cultivation technique that is not yet fully optimised represent significant risk factors. The analyses confirm that these crops are economically vulnerable when yields are low, but also show that they can become profitable if further optimisation succeeds in increasing and stabilising yields.

Multivalorisation
In addition to optimising cultivation and quality, the project clearly demonstrated that the production of aromatic root crops generates a wide range of biomass streams that are currently underutilised. A multivalorisation guide was developed, systematically mapping these streams for horseradish, garden angelica and lovage, and demonstrating that both main products and by-products (such as leaves, stems and non-marketable root fractions) contain valuable aromatic and bioactive components. By identifying potential applications and processing routes, the guide provides practical tools to improve the valorisation of residual streams. This creates opportunities for more circular and economically viable production systems and supports growers and processors in developing new markets and revenue models.

Processing and inspiration
Frank Fol and Dagny Ros, two chefs developed 13 inspiring recipes with the aroma-roots. These recipes were collected in a recipe book which can be requested at Flanders’ FOOD.

In summary, the results show that horseradish, lovage and garden angelica offer clear opportunities for growers and processors in Flanders. However, cultivation reliability strongly depends on seed and planting material, cultivation technique, weed management and harvesting method. Further trials and upscaling are needed to integrate these crops into Flemish agricultural practice in a sustainable and economically viable way.

Access to the project results

The project ended on December 31, 2025. The project results are available at the aroma aroma-roots platform.

Follow-up actions

During the Aroma-roots project, the first steps were taken towards developing a profitable cultivation and processing chain. However, several challenges remain that require further insight. For this reason, a follow-up project, Sapiroot, was launched. The ultimate aim of Sapiroot is to further optimise the cultivation of horseradish and garden angelica, so that these crops become sufficiently robust and agronomically reliable for practical application. From a cultivation perspective, several aspects still need to be clarified, including yield stability, quality parameters, and harvesting and storage strategies.

In addition, it is necessary to develop additional application domains in order to create a sufficiently broad and stable market for the crops and any associated by-products. The food industry in particular has expressed strong interest in the content and quality of the aromatic oil

Projectpartners

Flanders' FOOD managed and coordinated the project. The implementation was in the hands of:

• ILVO Plant (Merelbeke) under the direction of Gerda Cnops (gerda.cnops@ilvo.vlaanderen.be)
• Boerenbond (Leuven) under the direction of Stijn Bossin (stijn.bossin@boerenbond.be)
• Praktijkpunt Landbouw (Vlaams-Brabant) under the direction of Rutger Tallieu (Rutger.Tallieu@vlaamsbrabant.be)