Soilless Cultivation For Ornamentals

Growing plants without soil is a precise method to deliver water and nutrients to match crop demand; because of the enhanced availability of resource to the root-zone, crops can be grown at a higher density than would be possible in the field.

Ornamental crop production requires robust plants that can be grown to a tight schedule and specification which are sufficiently tough to show vigour before and after sale. The ornamentals sector is also seeking to optimise resource use efficiency, particularly in terms of substrate use, to enhance both its environmental and economic sustainability.

Hydroponic growing techniques can be used to achieve these aims in a variety of ways. Rather than relying on soil to provide water and nutrients (supplemented with fertilisation/irrigation as required), hydroponics use an inert substance to provide structure and support for the roots, while carefully controlled nutrient solution applications provide all the water and nutrients that the plants need throughout their lifecycle. This can be used on a wide variety of scales from a shrub in a 2L pot to a six-pack of varied bedding plants, but in each case a plant is grown with a well-developed, compact root structure in minimal amounts of substrate.

The technology can also be applied in the cut-flowers sector, where longer grown plants such as rose can be maintained in a productive state throughout the season. Hydroponic production can be extended to a wide range of plant types grown in the same system.

For Welsh growers focusing on local supply, the ability to provide a range of plant types to their customers will increase customer access. Precision application can shorten cropping times, enhancing the ability of growers to match customer orders and periods of peak demand. The systems can also be extended to cover edible crops (especially herbs) which growers can use to further expand their product range.

Through this route, hydroponic product aligns with the long-term vision of the Welsh Government for horticulture, both by promotion diversification away from traditional horticultural outputs and by enhancing the efficiency of production from raw resource inputs to short, more compact local supply chains.

High planting densities also increase the efficacy of biological controls for pests and diseases, and better control of the root-zone allows for reductions in persistent root diseases. Low labour costs result from stacked or table-height production, and the ability to control the growing environment means that optimum resource efficiency can be achieved while offering a highly uniform and consistent product that has the potential to be grown year-round.

Cultivation without soil also means that the crop won’t become contaminated with soil enhancing marketability. The recirculation of water and nutrients means that water wastage is 20 times less than that typically seen in soil grown systems, enhancing the sustainability of the cultivation process. While soilless cultivation methods can be started on the small scale using simple technologies, it also blends well with innovative growing technology such as lightemitting diode (LED) lighting, crop sensing technology and carbon dioxide enrichment; providing excellent scope for expansion and growth.

This document has been written as a practical guide for growers who are seeking to diversify their business using hydroponic techniques.