Slow Release Fertilizer NPK

Hi All.I do not know if you are like me but when I want to buy something like say a camera or phone I delve into the technical bits so much I get confused and may as well take a lucky dip at what I buy.

This has happened with the Slow Release Fertilizer for baskets & containers.Now I have never used it before but relied on mixing feed up in watering can and using about once a week.Now I was looking at Mirical Gro and also Wilkinson's own brand.However I was walking through the 99p shop and came across jars of 360mg Feed & Gro
Slow Release plant food for 99p so I purchased 2 jars.

On getting home I noticed on the label NPK 15-11-15,now I have never seen this before so done some research on google and as you know it refers to how much Nitrogen- Phosphorous-Potash it contains.
Now you buy fertilizer with the correct NPK for what you want to feed, be it roses ,lawns or general plants.

Where I got lost was what is the correct balance for baskets & containers and what they did not say was what quantity of each NPK is high or low if you see what I mean.All it tells me the plant need a quantity of each to flourish.
To make it more confusing when I checked a couple of different brands all the NPK numbers are different in fact for Miracle grow I read 2 sets of different numbers.
Miracle grow 17-9-11 or 18-9-11
Feed All 14-5-27

Now I rather not use my 99p shop food if the NPK is wrong or am I getting too deep into this for my own good??.As you know some 99p shop goods are okay and some just diabolical so any input would be grateful.

I also purchased 2 bags (1.25Kg each) of Doff Bonemeal at 99p each plus some compost maker also by Doffs.I looked on web and same Doffs sells for £4-5 for the same bag.Now I do not need a big tub so I thought this was a bargain.
Thanks again
P.S I see on Gardening Direct and no doubt elsewhere you can get plant food for almost any particular plant,be it Geraniums,Begonias,Petunias,Strawberries,Polyanthus & Primula etc.You could spend a small fortune at £6:99 a bottle.Do you think we need a particular food for a particular plant or a general plant food
would be suffice.I suppose if you are showing in competition it may be different

 

Note that 10-10-10 is the same as 20-20-20 (but the second one is twice as strong, so you only need half-as-much :thumb: )

So on that basis your 15-11-15 is similar to the Miracle Grow (which probably has two figures to take care of both the UK and the Irish [or possibly EU] way of displaying such things - one of them is Soluble amounts, whereas the other includes the insoluble, or something like that - I just stick to the UK NPK figures as that's the one I cam familiar with)

The specialist fertilizers usually have different balances of trace elements - presumably carefully selected to be best-suited to the specific plant type.

I use Westland long-season Feed-All fertiliser for my Tubs and Baskets, it looks like "hundreds and Thousands"

 

Hello Trogre
I have the same problem of over researching things , it is so easy on the internet . You can then suffer from the over technical golfers complaint - paralysis by analysis ! :D
I agree with Kristens advice , I also use Westland slow release fertiliser for all my containers and baskets . I would think that all of these slow release pellet fertilisers are pretty much the same , you would be very hard pressed to notice any difference. Also the Doffs items you bought in your £ shop will be fine , it is a reputable make . As you said folk who grow for exhibition , may need the very specialist fertilisers , mortals like us will be ok with the standard stuff

 

Hi Trogre

I think the problem is that unless you work in a specialised research lab looking at this, the general public are in no position to judge. We must have faith that the contents are what they say and that all the trace elements, ie things other than NPK, are right.

My view is that you need to give plants enough. You can either do this with a smaller amount of highly concentrated food or a larger amount of less concentrated food as Kristen said. If one feed is low in one element, feeding a bit more will ensure it has enough.

What is enough? Well as long as you give plants some - you have done much better than not giving them anything. Other than that, its really a matter of trial and error. If in doubt I prefer to overfeed (in the growing season). I can't say that I have ever had any ill effects from overfeeding. Even the bank balance doesn't really notice it.

With a liquid feed, the box may say to feed once a month. I try to feed every week. And with Brugmansia, I feed double strength - every day. They love it.

The other thing to remember is that early in the season plants like a balanced feed like Miracle grow, but later on when they are flowering or fruiting they like more K (Potassium) so I use Phostrogen or the equivalent. Its the same as tomato fertiliser. But I won't ever buy liquid feed - you are mostly paying for water.

 

I usually just add a hand full of osmacote to containers, but I do use a high potash feed occasionally in summer as a back up.

As to all those specific feeds for certain plants, I think its just a matter of getting people to buy 10packs of fertilizer when one would do.
There are a few exceptions but mostly I just buy the balanced stuff and high potash.

 

If you use a slow release fertilizer does this mean you don't need to feed all season or do you still liquid feed after so long?

Cheers
D

 

My Westland "Feed All" says it lasts 6 months. I tend to also give supplementary liquid feed, but:

1) I've never done a side-by-side test and only given one half extra feed - I may be wasting my money!

2) I don't make a note of when I give the extra feeds - so I dod it when I remember, and when it seems like its been "quite a while" since the last time so, hopefully, at the least the slow-release fertiliser tides the plants over between my irregular & erratic extra feeds.

 

I asked a nurseryman once how he fed his plants, and he said he gave them all Osmacote - but also gave them a liquid feed as well - I think he said once a month.

As Osmacote is expensive, I just give them a liquid feed made up from Miraclegrow (or equivalent balanced feed) early in the season and Phostrogen (or equivalent high Potassium feed) when they are flowering. Usually once a week - when I remember.

 

Good question Exlabman , I use slow release in my containers , then Miracle grow every now and then and from August I use tomato fertiliser. As you say if the slow release fertiliser last 6 months are we wasting our time and money ? I was told more isn't better for fertilising.

 

Plants will take what they want from the soil. Putting more down is the same as taking lots of vitamins - burning money! Although you are making sure that (within reason) what they need is available and "on tap"

It needs a side-by-side test. How about we use long-life fertiliser on all containers, coupled with a "when I remember" policy of adhoc liquid fertiliser on all the plants on the Right side of the front door (as you go in)? :D :D :D

 

Good idea Kristen !:D But as a gardeners we rely on myths and old wives tales not scientific experiments :D

It does seem like we all have a pretty similar feeding regime probablly most of us using Kristens "when I remember" method.