Driven by demand for year-round production-controlled environment agriculture (CEA) is increasingly the preferred method for strawberry growers worldwide. “While we see high-tech production of strawberry scaling up in North America, Middle East, Asia Pacific and here in Europe; propagation remains centered on using cuttings grown from mother plants, in most cases in open field situations”, says Thomas Peters, Business Development Manager at Grodan. According to him the strawberry market needs to adopt a high-tech mindset also in propagation to fully maximise yield of high-quality fruits.
Groundbreaking research
”As part of our commitment to advancing the whole industry through groundbreaking research, Grodan has conducted strawberry propagation and cultivation trials for several years,” he continues. “We now have detailed growing protocols and fertiliser recipes for strawberry propagation and cultivation, and we really see impact on production when high quality young plants are used. These protocols are being updated with new knowledge we generate together with our partners.”
Most strawberry plants are still propagated outdoors from cuttings or ‘tips’, but this increases the risk of pests and diseases being brought into the greenhouse, he explains: “That doesn’t align with a high-tech approach and with the ‘clean start’ offered by our stone wool growing media. We have worked with Limgroup for some time and have noticed some interesting developments in seeds, so we decided to set up a joint trial to explore the opportunities together.”
Disease-free from the start
“We discovered we share a similar vision of the future. Both companies are forward-looking with highly innovative products, making this collaboration a perfect fit,” comments Roland Sweijen, Product Lead for Strawberries at Limgroup. “Just like Grodan’s stone wool growing media, our F1 hybrid seeds are disease-free. This helps growers avoid diseases linked to low-tech propagation, such as Neopestalotiopsis which cause major issues for high-tech strawberry growers.”
A clean, healthy and uniform start for young plants improves efficiency throughout the production cycle, explains Sweijen: “Clones from cuttings develop at different speeds, so steering based on averages means it’s sub-optimal for 40% of the crop. In contrast, F1 hybrid seeds are identical, resulting in the best uniform plants. This allows the greenhouse climate and irrigation control systems to be optimised for all plants. This makes it easier to manage the flowering, production and harvesting stages and enables growers to share more accurate supply forecasts with their retail customers.”
Data-driven steering
Stone wool’s suitability for precision growing further enhances crop performance, according to Peters: “By monitoring real-time data using GroSens sensors, we know exactly what’s happening in the root zone with water content (WC%) and electrical conductivity (EC). We can steer the irrigation strategy according, adjusting start and stop times as well as volume and frequency based on the incumbent weather conditions. In doing so we maintain root health. This data-driven approach to steering gives you precise control over your crop, leading to more consistent quality, high Brix, and better production efficiency compared to traditional growing.”
Sweijen agrees, adding: “Unlike traditional substrates, stone wool starts with a neutral baseline. This makes it easier to give the plant exactly what it needs at each stage, without having to account for the buffer in organic material.”
Year-round planting and harvesting
Using seeds also offers propagators and growers more flexibility when planning crop cycles. “Fresh plants propagated from cuttings are usually only available for a few months each year, making it difficult for growers to optimise their production window. In contrast, everbearer F1 hybrid strawberry seeds can be sown at any time, of the year giving propagators and growers the freedom to sow, transplant and harvest all year round,” explains Sweijen.
He adds: “As costs continue to rise, it is vital for growers to optimise their efficiency and protect profit margins. Labour is a big part of this. A high-tech approach makes labour and other production-related costs easier to control.”
First findings
A comparison trial was conducted at Delphy ISFC to evaluate strawberry cultivation using Limgroup’s Limore One hybrid strawberry seed on Grodan stone wool growing media compared to traditional growing media. The trial began in January 2025, using plants seeded in early September 2024 in Grodan stone wool 240-cell trays. Two types of propagators were involved: a high-tech vegetable propagator and a strawberry propagator. The vegetable propagator used Grodan’s blocks for propagation, while the strawberry propagator used traditional growing media. During the cultivation phase stone wool and traditional media were used respectively. The objective of this trial is to directly compare plant performance between the two growing media, assessing the impact of Grodan stone wool on strawberry growth and yield relative to traditional methods.
“The initial findings show our seeds have a better germination percentage and produce a higher percentage of usable plants on stone wool compared to traditional substrates,” states Sweijen. “This indicates hybrid seeds such as our Limore One are an excellent match for high-tech propagation and cultivation on stone wool.
“Everyone who has visited the trial greenhouse has been impressed by how well the Limore One plants are performing on our stone wool. We’re seeing a very uniform crop, above-average kg/m2 production figures and high-quality fruits,” says Peters. “The trial continues for a few more months, but we expect very encouraging outcomes at the end of the season that we will share with the industry.”
A higher-value future
The conclusion is clear, according to Sweijen. “When you combine F1 hybrid seeds with stone wool, it really is a case of ‘one plus one equals three’. The best genetics on the best substrate gives the best result,” he states.
Uniformity and stability hold the key, adds Peters: “Our companies’ products are optimally designed for high-tech environments. Limgroup’s uniform starting material combined with Grodan’s uniform growing media produces strong, uniform, stable and healthy plants – especially when supported by data-driven insights and our expert advice.”
The research partners believe this is just the beginning. “In the longer term, I believe we could more than double today’s typical yields by combining seeds with stone wool,” comments Sweijen.
“It will require the industry to adapt to a new approach to propagation,” adds Peters. “But the biggest gains always come from thinking out of the box. We’ve seen how high-tech methods have transformed crops like tomatoes. There’s no reason why strawberries can’t follow, opening up a higher-value future,” he concludes.
