Pot Mulch

There is an increasing trend among growers to reduce chemical inputs not only because it is hugely time demanding and costly but also because of the environmental side effects. Many growers are turning to pot mulching as a way of reducing these effects. A layer of bark mulch on the pot surface is an excellent way to reduce moss, liverwort and weeds and offers a host of other benefits. Melcourt Potting Bark and Melcourt Propagating Bark make ideal pot mulches. They are: coarse enough to present a dry surface and allow free passage of irrigation free-flowing, easily covering the entire surface of the pot with no gaps evenly graded so ready to knit into a resilient, wind-resistant surface resistant to shrinkage on drying so no gaps appear very easy to apply either by hand or by machine, with minimal requirement for protective clothing and no formal training required non-damaging to stock – non-phytotoxic and no restriction on protected crops competitively priced against herbicide use long lasting enough to maintain an attractive appearance until the time of despatch – a single application is all that is required certified as restricted inputs by the Soil Association, so suitable for organic weed control Another benefit of pot mulching is a reduction in evaporation from the pot surface. In-house trials at Melcourt’s trial site near Cambridge have demonstrated the huge value of the extra moisture afforded by the use of a pot mulch. Here Choisya ternata Aztec Pearl is grown without a pot mulch on the left and with a 2 cm layer of Melcourt Potting Bark on the right. The plants were grown in a glasshouse and given identical watering. This picture was taken 7 months after potting / mulching. How to Use Melcourt Potting Bark and Melcourt Propagating Bark are very easy to apply whether by machine or by hand. It is essential that after potting a lip of at least 2 cm remains as a retainer for the mulch. Without this the mulch will not stay in place. Apply about 2cm of bark to the compost surface. Ideally water well prior to removal to the standing ground. Moss and liverwort are usually completely controlled provided that the mulch maintains 100% cover of the pot surface. Weed growth depends on the local potential and some growers find that a limited application of herbicide is also necessary to achieve 100% weed control. However, any weeds that do appear are weakened and more easy to remove when the pot mulch is used. Pot mulches with glue At Melcourt we have investigated incorporating a glue into our pot mulches to stop the bark getting displaced from the top of the pot. After a significant amount of work in this area we have come to the conclusion that the added costs are not outweighed by any true advantages. We found that the glue did not activate quickly enough to protect against movement of the mulch in the vulnerable period just after potting and that its effects wore off after a few months. We also found that it was difficult to keep the glue evenly distributed amongst the bark, whilst in the bag, giving inconsistent results. Using an evenly graded bark such as Melcourt Potting Bark and Melcourt Propagating Bark, both of which knit together very well and have a natural resistance to movement, in the end proved to be as effective as the glue-amended versions and we would recommend them without reservation. Contact Melcourt on 01666 502711 for any help you require regarding pot mulching.