Chilli plant flowers. Fertilizing

Fertilizing the first buds of the season

A couple of my Thai Demon Chillies that I started from seed  have already reached maturity. They have already started getting buds. Once these buds turn into flowers, with a bit of encouragement, many will turn into Chillies. To facilitate this,I will start fertilizing these Chilli plants with a water-soluble fertilizer that is high in potassium.  Potassium improves flower formation and fruit set.

What does this fertilizer contain?

The fertilizer I will be using (Chempak 4) has a NPK (nitrogen / phosphorous/ potassium) ratio of this fertilizer is 15 -15 – 30. It is applied at the ratio of about two teaspoons to five litres of water.  It is a blue powder that easily dissolves in water. The nitrogen is there to promote plant growth, the phosphorus for root growth and the potassium for flowers and fruit set.  The higher potassium level, in comparison to the rest of the elements, shows where the emphasis is being placed.  This  emphasis is , of course,  on flower formation and fruit set.

When considering that up to now, these plants have been  fertilized only with Chilli Focus ( NPK ratio 2.7- 1.0-4.4 at 5 ml per litre), this is quite a big  step up.  Indeed, some might even say that the higher levels of potassium  are  too much. But, are they?

There are many schools on this. Some say Chilllies don’t like being fed at all, especially when it comes to nitrogen. Others say Chilllies are heavy feeders.  Yet others say they are medium feeders when they have small fruit, but need lots of fertilizer for bigger  Capsicums  (eg Bell peppers).  It can all be quite confusing !

My view is more middle of the road.  Especially when you plant in pots,  Chillies definitely need a reasonable amount of fertilizing. Giving them too much fertilizer will harm them. Too little is not good either. You should make sure they  get just enough to do well.  This is sometimes easier said than done.

But just how much is enough?

The proper way of determining how much fertilizer to apply requires an analysis  of your soil . Test kits are freely available online to do this. After the analysis you can find out what deficiencies are in the soil and then make a decision on what fertilizer to use.

I personally don’t go to this level of analysis. This is where for me my tried and tested fertilizers step up the plate. Especially when they are specifically formulated ( like Chilli Focus) for growing Chillies .

To get seedlings started it is unnecessary to give them any fertilizer until they have developed their first set of leaves (cotyledons). There’s enough nourishment in seeds  to keep the seedlings going to this point. After that, use fertilizer like Chilli Focus at a weak concentration of about 2.5 ml per litre.  Do this until the plants  get their first true leaves. From there follow the advice of your fertilizer supplier.

Chilli  Focus  advises using 5 millilitres  per litre for   young plants . They   recommend  doubling the  dosage to 10ml when the first flower buds are noticed  .  While not specifically formulated for Chillies, other growers use  tomato feed with an NPK of 4-3-8 . It  is applied at 20ml per 4.5 litres of water on the first signs of flowering.  Prior to this, the tomato feed is watered down to about half strength.

Can you use a combination of fertilizers?

I am a great fan of Chilli Focus. It is my number one choice for seed starting (at a low dosage) after they have their first set of true leaves.  I then  use it  at the recommended dosage until  my  plants are potted on for the final time.

I then use  another fertilizer (Vitax Q4) to prepare the soil for the last repotting (see note).  After that , I continue using Chilli’s Focus until the  plants start flowering . This is where things deviate from the way I did things in previous seasons.

Previously I would have carried on using Chilli Focus    after flowering had begun . I would  have simply doubled the dose from five  to ten millilitres

However , because of a bit of experimenting I did last year , I now switch to Chempak 4 ( the high potassium fertilizer)  at the first sign of buds. The improved results in fruit set are very noticeable . It is definitely a step up from using Chill Focus alone.

So, while some might not agree, I think  it is beneficial to change fertilizers to suit what you need to achieve . During  final potting on , give the seedlings lots of nitrogen and phosphorous( e.g. with Vitax Q4) to initially get good growth.  Then reduce these elements and increase potassium (with Chempak 4) to encourage flower formation and fruit set.  For watering prior to flowers forming use Chilli Focus, then use only Chempak 4 for the rest of the season.

You don’t want to overdo it . If you feed Chilli plants lot  of nitrogen and phosphorous for too long, you will get healthy bushes but no fruit. It is essential to start reducing these elements once the plants have grown adequately.


Previously I would have used fish blood and chicken pellets to prepare the soil in the pots for final potting on.I now only use this fertilizer alone.

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