Firstly, what is a Root Trainer? The term ‘root trainer’ says it all. Essentially, it’s a container that is designed to encourage a healthy root structure at the propagation stage.
To ensure plants grow a vigorous root system before they are transplanted into the ground, growers use a variety of nursery products depending on the crop. Our best sellers are the 28 Deep Square Cell Tray and 50 Cell Tray, Root Pouch Grow Bags and sometimes, the traditional plastic root trainers – Hilson and Tinus.
There are many different sizes and materials, but essentially their role is the same – to encourage a good strong root structure.
Plastic root trainers have large air holes at the bottom to drain off excess water and stop the roots from growing when they extend outside of the pot. This is called “air-pruning” and is nature’s way of signalling to the roots that there is no more soil to grow into – the plant then creates new root growth elsewhere (leading to a thicker root system inside the pot) and means it can absorb more water and nutrients from the soil.
If a plant is in good shape with deep roots before it gets transplanted into the ground, it has a far better chance of reaching the nutrients in the soil to survive and thrive.
When we train a plant’s roots to grow downwards, they are less likely to get tangled up with the roots of neighbouring plants or compete for water and soil nutrients. There is also less chance of cutting the roots when removing a plant from its pot. Roots that are cut have a higher chance of disease.
What products do we recommend?
We understand the importance of cost-effective nursery bags, pots and trays – products that are long-lasting, can be reused and wherever possible are automation friendly. We advise customers to use the 28 Cell Deep Square Tray and 50 Cell Seedling Trays instead of the traditional plastic root trainers, Hilson and Tinus. It makes economic sense, e.g. when you compare the cost per cell of the 28 Cell versus the Tinus (both have .5L capacity) the 28 Cell works out at approx. 14c per cell versus the Tinus which is about 47c/cell. Spinifex grass is the exception to the rule here. Spinifex have a delicate root system and will respond well to the Hilson or Tinus root trainer due to the easy opening “book” feature which reduces damage to the root system at the point of planting – encouraging better survival rate.
Finally, the Hilson and Tinus require a mount or rack to hold them off the ground to allow for air pruning to occur. Their tapered shape prevents them from standing on their own.
50 & 28 Cell are perfect for natives like Manuka and Kanuka.
Like traditional root trainers, the 50 & 28 Cell have grooves inside of each punnet which prevents the roots from spiralling around the pot. They’re also automation-friendly.
Councils across NZ are very particular about the condition of roots, because if they are tightly bound the plants have a tendency to blow over in the wind due to inadequate lateral roots. Our propagation trays will encourage high success rate.
Don’t forget, frequent watering will be important. The hole at the bottom of the propagation tray means water drains quickly, which is good because it prevents over-watering, but it does mean regular irrigation is essential to avoid soil drying out and damaging the root system. Talk to us about automating your irrigation efforts – it can be simpler than you think.
For bigger trees, an industry best-seller is the Smartgro Fabric Pots. With two handles for easy transporting, the breathable fabric of these pots provides a healthier root environment – allowing oxygen to easily reach the roots. This material also generates superior insulation qualities, protecting roots from hot and cold conditions, while trapping the root tips to prevent them circling and girdling – in turn helping the plant to produce a dense lateral root structure.
What other products are useful when purchasing root trainers?
Our Polyon Fertiliser is an easy way to provide a consistent feed throughout the growing season. We can sell direct, or via your potting mix supplier.
If you would like further advice about propagation in general, or the best products for your project or nursery – please get in touch with our sales team.