Help with chilli plant growing

I'm ~3 weeks into a chilli plant growing competition that ends in mid/late July. I've never grown a plant like this before and I could really use some advice. Here's my plant about 1 week ago: -

There are 3 goals here: 1. Tallest plant, 2. Highest yield, 3. Hottest chilli.

I have a few questions: -

1. How often should I be watering it to maximize it's height? I realize I should later reduce the watering to increase the hotness of the chillis.
2. Is there any truth to the following rumour I keep hearing: "Pruning the smaller leaves focuses more of the plant's resources on growth, producing a few larger leaves which are more energy efficient" - I really don't want to do this, surely there would be a strong evolutionary bias against growing small leaves if they are less efficient? However the biggest 2-3 plants have all done this.
3. If I mainly leave it indoors is it smart to build a small greenhouse around it? Should this have holes in? The temperature indoors can vary quite a bit.
4. I have bought the following: http://www.lovethegarden.com/product-details/miracle-gro-gro-your-own-fruit-vegetables-concentrated-liquid-plant-food how should I apply this? The instructions are terrible, they aren't really made for a single plant in a single pot. The concentration it suggests is 50 ml diluted in 4.5 l and then applied once each week (to three plants!), this can't be right? Should I calculate the final concentration, dilute down and space it out over the week with the regular watering? - this could waste a lot of time.
5. Can you give me any other advice.

I'm sorry this isn't very clear, I'm in a rush at the moment.

Thank you.

Try this http://grapefruitopia.com/chillicare.shtml 'Solution' reply if this helps 

'Solution' highlight the website address given above> right click> then click either 'Open Link' or Open Link with New Tab

Thanks Lalat, I read the page you linked. I've done most of the things it has suggested (I used small rocks instead of polystyrene).

They suggest using 1 or 2 pinches of plant food every week. I still need to know how I can do this with the plant feed I have: the instructions suggest diluting it in 4.5l of water, but if I were to add this once each week I'd kill the plant. Should I instead add it in its concentrated form, or would this be worse?

Thank you

I always use liquid tomato food for my chilies and peppers. For yours then about 12 ml to a ltr of water should be about right. You can use the excess to feed other plants. I feed mine once a week. Good luck.

solution, to answer your questions:

1. Water only when the plant needs it. Let the mix dry out between waterings. Neither toms nor chillies - not many other things - benefit from overwatering. In addition, the fruit's heat is basically dictated by its genes, though cultural factors can have an impact. But a mild variety won't produce a hot chilli. You'd need to start with a hot variety.

2. There's no real evidence that plucking smaller leaves achieves anything.

3. Like toms, chillies need as much warmth and sunlight as they can get. Get the plant outside if you can, even inside a small greenhouse with some ventilation.

4. Like toms, chillies benefit from a fertiliser that's low in N (nitrogen), higher in P (phosphorous), and even higher in K (potassium). Too much nitrogen and you'll get foliage instead of fruit. Phosphorous is good for the plant's overall health, root structure, and flower development. Potassium aids the development of fruit.

The product you've bought has an NPK of 3:2:6. It's not too bad in the sense that the potassium percentage is double the nitrogen. A specialty tomato fertiliser with an NPK along the lines of 39 would be better.

But, anyway, you can scale down the manufacturer's recommended dosage. They cite 4.5l or about a gallon. Divide by, say, 4 to give you a manageable amount, a litre, dividing the amount of product by the same amount.

You probably won't use a litre when you fertilise. A litre might last two feeds.

As with overwatering, you need to be careful about overfertilising. Chillies, like toms, won't do their best if overfertilised. When they produce fruit, they're seeking to reproduce themselves, and they're much more likely to do so if they think they need to - in other words, if they're feeling vulnerable. Tough love works best in terms of both watering and fertilising. I wouldn't fertilise more than once every couple of weeks.

Mmmm. The edit function isn't working. That strange devil symbol in the NPK ratio should be a 6.

Thank you everyone for your help. So much useful information!

I wasn't sure about the potassium content ideal for chilli growing so I selected the lowest N:P ratio, which I read somewhere else was very important for this type of plant. Thank you for explaining the reasoning, Italophile, I like to understand what it is for. The original plan was to go for a tomato fertilizer, but then I saw this one had the lower N:P ratio than the tomato one available in the shop.

I've added the fertilizer now. I mixed ~12 ml into ~500 ml of water and am slowly giving it a bit every day or so with its usual watering.

I have 2 more questions: -

1. It says on other sites that this variety of chilli (Apache) is a dwarf variety that grows up to 60 cm tall. Mine is currently ~17 cm and has started producing flowers (although still closed and quite small) and hasn't really grown much for a week or two now. Will it continue to grow whilst flowering or does it usually stop there and just become thicker? I have noticed that almost all of the (20 ish) plants have really slowed down in growth and a lot of them have open flowers now.
2. I see black marks at every point where the branches meet the stem. This is also on most of the other plants. Can anyone tell me what causes this?

Thank you again.

I'd cut back on the watering, solution. It won't need water every couple of days. You can afford to let the mix dry out between waterings. And I wouldn't feed more than once every couple of weeks. As I said above, chillies are like toms - they will produce best if they sense they're struggling a little. Tough love is the go.

Apache is a dwarf which makes it ideal for pots. Yours has some growing to do yet and it will produce more flowers.

Those black marks are very typical. It's just pigmentation.

great advice, I will cut back on the watering. So it will continue to grow taller even when it's producing flowers and fruit? - I really didn't expect that.

Thank you

Out of interest, can you think of anything else that I haven't considered which would help it to grow faster?

It's a bit like a determinate tomato - the fruit on the branch marks the end of the branch's growth, but the plant itself fills out. Here's a photo of an Apache plant at its peak:

There's nothing you can do to force the plant. Just give it as much warmth and sunlight as you can. They thrive on both.