Over-seeding is a common element of autumn renovations. Costs for having the work done will be around £300-£500 depending on seed type, application rate and method used, but is this value for money?
In the vast majority of cases the answer is sadly…no! Why?
There are many reasons why over-seeding can turn into an expensive and in-effective luxury. First of all it’s an easy sell for contractors; after all what’s not to like about it? It’s non-disruptive, relatively cheap and promises a surface free of bare patches and populated with fresh new vigorous grass next year.
Unfortunately it doesn’t work like that.
First of all the new seedlings are up against very stiff competition from the existing, mature sward. Sure, you will see an almost 100% success rate at around 14 days after seeding in a lot of cases and your contractor will be quick to point this out to you. However, at this point the seedlings are still living off mum as it were. The seedlings rely on reserves of energy held within the seed husk to provide them with nutrition while they get their act together. Very soon though they need to stand on their own two feet and compete for food, moisture, air and light with the locals and at this point it isn’t uncommon for the survival rate to reduce to as little as zero.
Current turf/soil condition, seed selection, over seeding method, timing of the operation, soil preparation and operator skill in that order are all key aspects of the success or failure of over seeding operations.
A very useful fact sheet! Can you just clarify…. you say severe scarification…. are you referring to the depth of the scarification or scarifying more than once prior to seeding?
Hi Robert
This will depend on the current conditions on the green.
The idea is essentially to weaken the indigenous sward enough to give the new seedlings time and space to get established.
This normally means scarifying quite hard in at least two directions. If the turf doesn’t look like it would take this then the green probably isn’t ready for overseeding anyway.
You should only ever use mechanical (e.g. scarifying) means to weaken the sward and only weaken it when it can reasonaby be expected to recover fully, so not too late in the year.
There are some crazy people out there who advocate messing around with week dosages of glyphosate, which is of course a dangerous game to play and shouldn’t be attempted at any cost.