Please could I have some advice re: When I should be re seeding/ scarifying my lawn in preparation for this year.
Labradouble, you can really start around mid March onwards. This could vary according to your local weather. Give the lawn a light rake to lift the blades upwards and mow your lawn on highest setting. Scarifying is mainly done in autumn time or once your lawn has extablished more.
Re-seed after you have done that, just lightly rake the bare patches and sprinkle the seed according to instructions and rub some finely sieved topsoil or surrounding soil on top and water in if no rain is forecast.
If you have an electric scarifier it can be pretty rough on the grass, so you want your lawn to be at its most resilient when you do scarify, i.e. long enough after winter so it's growing well, but before any droughts kick in. Personally I wouldn't scarify before April in a typical year, possibly late April if you're up North.
I plan to fertilise the lawn 3-4 weeks before scarifying to give it an extra boost. I favour pelleted chicken manure. When you scarify, first mow the lawn tight (but don't scalp it) and make sure it's dry - this will minimise the impact. Afterwards you can top dress and seed. If you plan to apply any lawn weedkillers, read the packet first - some suggest waiting 3 months after seeding.