Andrea Heistinger for AgroBiogel and RETENTIS®

When soil reaches its limits—and what Andrea Heistinger recommends to address it

Drought stress, depleted soils, and insufficient root development are no longer issues limited to vineyards and arable farming—they are also clearly felt in private and professional horticulture. Even humus-rich soils lose their water-holding capacity during prolonged heat periods, young plants wilt faster, and more and more organic gardeners are forced to rely on regular supplemental irrigation.

The solution: storing water where plants actually need it

With RETENTIS, our biogenic water-retention granules made from lignin, we offer a way to keep moisture and nutrients in the root zone long-term—without synthetic polymers. The granules are mixed into the soil and act for several years as a natural storage and buffer zone. The effect is especially noticeable during the establishment phase and in permanent plantings (fruit trees, perennials, hedges, vegetable beds, young forest): more root growth, less watering effort, and higher establishment success.

Who officially supports RETENTIS? Andrea Heistinger

We’re delighted that Andrea Heistinger—widely known as the author of works on organic gardening, seed saving, and resilient agriculture—stands behind AgroBiogel as an official testimonial.

She is not only a voice for holistic soil fertility, but also a hands-on practitioner who has tested RETENTIS herself in her own garden and raised bed trials.

Why Andrea Heistinger recommends RETENTIS

Andrea says:

“RETENTIS is a quiet helper in the soil: it strengthens plants from the inside out, instead of supplying them from the outside. This allows them to grow continuously and productively.” She especially values:

• Its biogenic origin: wood instead of petroleum

• Long-term effect without microplastics

• Supporting root architecture instead of purely surface-level watering

• Compatibility with compost, mulch, and organic management.

Who does Andrea Heistinger specifically recommend RETENTIS for?

She particularly addresses the following groups:

Area	Application	Benefit
Organic gardens & vegetable beds	Vegetable beds, raised beds, self-sufficiency gardens, perennial areas	Less watering, higher yields
New plantings & hedges	Garden & landscaping, tree pits	Higher establishment success
Agriculture & organic farms	Vegetable crops, fruit growing, young plants	Water reserve during dry spells
Forestry & agroforestry	Reforestation, tree seedlings	Protecting root formation during heat periods
Community & teaching gardens	Teaching gardens, initiatives, experimental plots	Faster development of fertile soils

For Andrea, RETENTIS is not a product, but a tool for soil vitality and plant resilience.

If you’re working with regenerative soil management, humus-focused gardening, or climate-adapted planting, RETENTIS is worth considering!