Page 67 - Simply Vegetables Spring 2021

Watering systems are great for eliminating the manual labour and the physical presence required by hand watering. The time you free up can be put to good use in advancing your growing techniques. With unfamiliar varieties watering systems can work in harmony with plant requirements - making it easy to get the irrigation regime right first time. If you’re ready to take the plunge with a watering system the next question is what media do you grow in?
Recent enquiries from N.V.S. members got us thinking; it’s high- time we talked about grow mediums suitable for use in AutoPot Watering Systems. What are the ideal qualities? What are the popular favourites? And how can you create your own - either by blending or improvising?
The first thing to be aware of is that soil or peat-based media can’t do it alone. Yes, it’s an excellent ingredient for supporting bio-activity, but on its own it’ll compact into a virtual solid leaving your roots, water, and nutrients with nowhere to call home. Don’t let this put you off.
Mixing in another medium is an incredibly cheap and simple way of ensuring that the perfect balance of aeration, water-retention, and wicking is maintained. Inexpensive and easily available, perlite or clay pebbles represent excellent additions. Irregular, porous, and rough surface textures such as those found on perlite granules are ideal for use in watering systems. They help produce a mix that is absorbent, light, and facilitates good capillary action - the drawing of water and nutrient solution up through the pot. This is vital in watering systems such as AutoPot where the supply arrives in a module tray below the pot. Clay pebbles are great too - the one caveat with these is that they must be pH stabilised for 48 hours before use.
What else works? Pebbles or perlite perform equally well with coco coir. The coir represents a natural, free-draining substrate that, if desired, can be enhanced with beneficial bacteria and fungi to strengthen the root-zone and accelerate plant growth. Look
for coco that has been buffered and stabilised. If unsure, pot up
Perlite adds aeration, water retention, and drainage to the soil in which this Khol Rabi is being grown – in 1Pot XL at Plantasia
Aubergines in a 70/30 Coco/Perlite mix – thriving in AutoPot 1Pot Modules at Plantasia
and pour approx 10 litres of pH 5.5 water and 1/4 strength feed through each pot - this will instantly stabilise the coco. Allow to drain thoroughly before use. Soil or coir can also be used with rock wool or Growstones. As with pebbles these are alkaline out-of-the-bag but are easy to pH stabilise before use. Then there are ‘improvised’ substrates.
Amongst our more intriguing improvised successes to date have been broad beans in plant reeds, chickpeas and lentils in recycled glass, and coriander in rice husks - some of which we’ve showcased at RHS Chelsea. We’ve tried bracken, denim, calico, pumice, and sheep’s wool to name but a few others. In Thailand we even tried dead coral, boiled to relieve the material of salt before being smashed up. It subsequently played home to a 20ft tomato plant in one of
our 1Pot modules. Currently we’re testing substrates to the point of exhaustion with tomatoes to assess just how effective they remain year-on-year.
Why should more obscure, improvised growing media be of interest to everyday gardeners? The short answer is; they might not be obscure for long. As with the wider world, horticulture is under pressure to function sustainably and find alternatives to traditional practices. At at time when the RHS and Woodland Trust are petitioning the government to ban peat-based composts it’s surely prudent to take a look at recycled or reusable options.
It’s not all worthy work though. A great deal of fun can be had experimenting with homemade media on a shoestring. Alternatively, for the connoisseurs, a watering system can play home to some
of the most exotic concoctions of high-end substrates imaginable. Trying out new and exciting grow media can easily become addictive! The variety of blends, the use of surprising materials, and the choice of ‘charges’ available adds whole new dimensions to growing. It’s easily as intriguing as seed choice, cross-breeding, or the honing of a perfect feeding regime.
ADVERTISEMENT FEATURE
What Lies Beneath – Choosing The Ideal Growing Media For Watering Systems
Simply Vegetables 67