Nursery stock grown outside has to contend with varying winter weather. Temperatures often fluctuate from well below zero to spring like balmy days along with periods of virtually no rainfall to monsoon like conditions. After enduring all of that the crop should then grow away, perform and make a saleable plant.
Not only do the plants endure all of those ‘ups and downs’ but so to does the growing media and, importantly, any controlled release fertilizer (CRF) within the root environment in the pot. The principle of any CRF is that when temperatures rise and fall more or less fertilizer is released into the compost, with Osmocote being the safest and most reliable.
Between October 2015 and February 2016 the temperature across different parts of the UK ranged between the seasonal average and a significant 3.50C warmer. Rainfall was a little more variable with isolated pockets of the country having less than average monthly rainfall, while the vast majority experienced anything from average to in excess of twice the monthly average.
These climatic anomalies have the potential to flush through any available nutrition held within the root area. This could leave some stock impoverished until the CRF within the compost gets to a temperature where it is releasing sufficient for the plant to grow.
A simple conductivity test can be used to demonstrate the levels of any soluble salts within the compost, while a more extensive compost analysis will reveal levels of all major and trace elements.
One way to ensure there is enough fertilizer in the correct balance is to topdress pots with a shorter release product to ‘fill in the gap’. ICL has two products designed specifically for this purpose to ensure your crop grows better, looks better and sells better.
OsmoTop will give a quick green up, releasing NPK along with a full trace element package over a 2-3 month period.
Osmocote Topdress (FT) is similar to OsmoTop but with the advantages of a longer release period of 4-5 months and Fusion Technology (FT) which sticks the granules to the compost surface. This ensures there is no loss of fertilizer when the pots (inevitably) fall over in the wind.