Got some spare chicken manure kicking about and wondering whether it will work well on your runner beans. Let’s have a look and find out if chicken manure is good for runner beans.
Chicken manure pellets have an NPK rating of 4.5 : 3.5 : 2.5 which means it contains more nitrogen than anything else, in fact, it has nearly double the amount of nitrogen to potassium (K).
This means it isn’t an ideal fertiliser for runner beans, runner beans are a nitrogen fixer and can actually pull nitrogen from the air and store it in the soil.
This doesn’t mean they don’t ever need nitrogen in the soil, but it does make it unlikely that you will need to fertilise with a nitrogen-heavy fertiliser.
There is also the danger of too much nitrogen being in the soil when growing runner beans, one of the side effects of this can be poor flowering and cropping.
So Can I Use Chicken Manure?
Fresh chicken manure shouldn’t be used for runner beans as it is even higher in nitrogen than the dried pellets are. Dried pellets or old manure can be used but they aren’t the ideal fertiliser.
What Should I Use?
You want high potassium, also called high potash, feed. Potassium promotes flower and fruiting so will give us more beans on our plants.
Tomato feeds are always a good fertiliser with a high Potassium rating, Tomorite Concentrate has an NPK ratio of 4:3:8 so we can see that is has a much higher level of potassium when compared to anything else.
What Does NPK Mean?
When we talk about NPK and fertilisers it is simply the ratio, not amount, of Nitrogen (N), Phosphorous (P) and Potassium (K) in the fertiliser.
These are the three main nutrients that plants need to grow, there are lots of other micronutrients that can be needed but NPK are the big three and they all do different things.
Nitrogen is responsible for green leaf and plant growth. A nitrogen-heavy fertiliser will promote lots of leaf growth and a larger plant but it doesn’t help with fruiting.
In fact feeding some fruiting plants with lots of nitrogen can be detrimental, they will grow tonnes and tonnes of leaves but precious little fruit.
A nitrogen-heavy fertiliser is a good fertiliser to feed plants in their initial growth stages when they are still establishing themselves and haven’t started cropping yet. This will help you get a larger plant that can then support more fruit, roots, seeds etc.
Phosphorus serves to help the plant convert other nutrients into usable ingredients, so it is essential to good plant growth.
If your plants aren’t getting enough phosphorus then they will be very small and stunted, they may not flower at all and will just generally look sickly.
A good thing about phosphorus is that you can’t really overdo it, plants struggle to take up phosphorus anyway so it is really tough to have too much in your soil.
So a multipurpose fertiliser like chicken manure that has some phosphorus in it is always going to be a benefit to your garden.
Potassium (Potash) helps plants overall and is essential for healthy growth. Where it is really useful though is cropping and promoting the growth of fruit, veg and flowers.
High potassium fertiliser is commonly applied when plants start cropping, they will promote larger crops when more potassium is added to the soil.
A high potassium feed is also used on decorative flowers as it will encourage more flowers to grow on the plant.
Potassium fertilisers are commonly called potash and these terms are used interchangeably by gardeners so don’t get confused if you are told to use a high potash feed, they just mean a high potassium feed.
They are called potash feeds because potassium fertilisers are commonly made from potash. You can see potash in its rock form above but it can also come from burning wood which is probably where the name originated.
Conclusion
You can use chicken manure pellets for runner beans but they aren’t ideal as they have high nitrogen to potassium ratio. Do not use fresh chicken manure as it has a really high nitrogen content. A tomato feed makes a much better fertiliser for runner beans.