Growmore?

Osmocote ?

Hi,
Slow release has tobe bone, its made tobe a slow acting fertilizer,
If you want to make your own liquid all round feed!
go for comfrey, its a plant thats grow for its large leaves

simple to make and really is very good,
nettle's can also be made into a liquid feed,

METHOD;
items needed = 1x drum (I have a 45 gal plastic drum bought from the gardencentre)
fill the drum with clean cold water, get a sack or mesh bag
(the sort of onion bag you buy your onions in from the super market, you'll need about 4 of the onion bags or 1 larger sack,
Fill the bags with as much comfrey or nettle weeds as you can cram in and also include half a house brick or some other weight to help sink the filled bag to the bottom of your container,
put a loose cover over the drum and leave for approx 3/4 weeks it will have a strong smell at first,
once these nettles or comfrey have rotted down the water with darken,
You've now enough good pure gardeners liquid gold to last you all summer, as the drum contents get lower just top it up the liquid will still be strong enough to keep feeding your veg/flowers/& shrubs,
the mix rate is 10 parts water and then 1 part of this mixed nettle or comfrey.
You can see from the 10to1 mix how strong this liquid is.

Ive used this and still do for many years and so i can say tried & well tested,
And you'll save a fortune on liquid feed.

I use osmocote in baskets and tubs, it works on temperature I understand and releases its nutrients slowly over the season as it warms up
Growmore is what Iuse as a general fertiliser in spring

The trouble with the artificial slow release fertilisers is that they rely on temperature to release nutrients. You can get the situation where there is a two week hot spell in April/May and the fertiliser starts to release nutriens whilst the plants/seedlings are still small and can't cope with it. Then, the weather turns wet and cold and the fertiliser doesn't release any nutrients when the plants need it most. I use bonemeal (some would prefer fish, blood and bone) which give a steady and slow release of nutriens through the season, and they are organic.

I understand what you're saying bulbaholic but if it's cold and wet, the plants don't grow, end of.

Feed such as osmocote are designed to release fertilizer at a temperature that coincides with a plant's growth eg if a marigold is in a tub and it's 10 deg C, the marigold won't be growing that much and the osmocote wont be releasing the feed.

Up that to 15 or 20 deg C and the marigold grows and the osmocote releases more nutrients.

Vitax Q4 pellets.