The season decides most fertiliser choices before you even get to the NPK numbers. Work out what stage the turf, tree or shrub bed is at, spring growth, the run into winter, or newly seeded, and the shortlist narrows fast. After that, it is really a question of how many times a year you want to be back out with the spreader.

Match the feed to the season and the job

Spring and summer feeds carry more nitrogen, because that is when grass is actively growing and can use it. Velscape Spring & Summer Fertiliser (12-6-6) is a straightforward 2-3mm granule for lawns and parks cut above 10mm, built for the March to August window. On turf cut shorter, Command Spring & Summer Fine Turf Fertiliser (14-3-8) uses a homogeneous 1-2mm granule that settles below the leaf instead of sitting on top of it, which starts to matter once you are mowing every day or two.

Autumn and winter feeds flip the ratio: less nitrogen, more potassium. Soft growth going into the cold months is exactly what you do not want, since it is the growth most likely to succumb to disease over winter. Velscape Autumn/Winter Fertiliser (4-12-12) and Command Autumn Fertiliser with Seaweed & Zeolite (7-0-14) both work this way; the Command version adds seaweed and zeolite to improve nutrient uptake, worth considering if a site has struggled to hold onto feed in past years.

Between the two, Velscape All Season (Growmore) Fertiliser (7-7-7) is a balanced general feed for borders, parks and turf that does not need pushing in either direction. And where the turf is not turf yet, freshly seeded or newly laid, phosphate does the early work: Velscape Pre-Seed Fertiliser (6-9-6) is weighted towards root development rather than top growth, which is what a new sward needs before it needs mowing.

Decide how many times you want to feed it

Standard release grades, most of the Velscape range included, give up their nitrogen within a few weeks, so you are back with the spreader every 6 to 8 weeks through the growing season. Slow release grades spread the same feed further: Command Slow Release All Season Fertiliser (13-0-26) uses methylene urea for around half its nitrogen, and holds for roughly 12 weeks rather than 6.

That is not automatically the better choice. A cheaper standard release bag applied more often gives you more control over how hard you are pushing growth, and it is easier to skip a round if the weather turns against you. Slow release earns its higher price where labour is the real cost: large sites, contract rounds, ground that is awkward to get a spreader onto, anywhere fewer visits matter more than the price per bag.

Trees, shrubs and biological turf care need a different approach

Tree and shrub beds want a different formulation to turf altogether, weighted towards phosphate and magnesium rather than nitrogen. Velscape Slow Release Tree & Shrub Fertiliser (4-19-10 + 8% MgO) feeds for 5 to 6 months from one application, and pairing it with Rootgrow Professional Mycorrhizal Fungi at planting gives the roots a fungal partner that lasts the life of the plant rather than one season.

On established turf, biological feeds sit alongside a conventional NPK programme rather than replacing it. Phoenix Pro-Bacter combines a granular feed with live Bacillus and Trichoderma, which break down thatch and dead moss as they work, without the black staining a traditional iron treatment leaves behind. That matters most on sites where the public walks straight across the turf after treatment.

Which fertiliser for which job

For most lawns and parks, pick the seasonal Velscape or Velvit grade that matches the time of year, and move to the slow release Command range once fewer visits matter more than cost per bag. Fine turf cut short does better staying in the Command range year round, since the granule size is built for that cut height. New turf and seed beds want a pre-seed, phosphate-led feed before anything else goes down. Trees and shrubs need their own formulation, and established amenity turf can take a biological feed alongside its normal programme rather than in place of it.

If you are still not sure which analysis suits a specific site, have the turf type, cut height and your realistic feeding schedule to hand and speak to the Phoenix Amenity team, or work through the fertiliser range by season to narrow it down yourself.

Frequently asked questions

Can I mix a standard release and a slow release fertiliser on the same site?

Yes. Many sites use a slow release grade for the main spring or summer feed and switch to a standard release, lower nitrogen product for autumn, when a fast green-up matters less than firm growth going into winter.

How do I know which granule size my site needs?

Granule size is mostly about cut height rather than spreader type. Homogeneous 1-2mm grades, like the Command range, are sized to settle below turf cut short, greens, tees, fine lawns. Coarser 2-3mm grades, like Velscape and Velvit, suit lawns and parks cut above 10mm.

Does a slow release fertiliser mean I can skip a feed altogether?

No, it means a longer gap between feeds, not none at all. A 12-week slow release grade still needs replacing once its nitrogen is used up, so check the longevity figure on the product page and diarise the next round rather than waiting for the turf to tell you.