Ok, guys, here's the deal. You CAN decandle JWP. But, it's risky. They might or might not send out new second growth shoots (candles). Therefore, since it's not reliable, it's not recommended.
The usual approach is to pinch back the strong candles to match the others around it. If there are more than two new shoots (candles), reduce down to two. The time to go this is just before the candle has started making needles. When it's done then, it will develop regular buds on the terminal for the following year.
Actually, during the winter, you can inspect the tips and see how many dormant buds there are. You can eliminate extra buds at that time.
JWP will backbud, but, they're not reliable. They can also bud where ever there is a needle bundle, but again, they're not reliable. Therefore, take pains to preserve as many branches and twigs as possible, especially interior ones. That said, we still don't want bar branches or places where 3 branches come off one point.
Now, if you're feeling that JWP are rather difficult, you're right! I don't recommend them for the beginner. They're fussy, and extremely slow growing, and their bark stays immature for 20 to 25 years before it starts to get rough. Their immature bark shows wire scars until it starts to get rough. Yeah, that's 20 to 25 years.
Other Pines, such as Scots or JBP are much more forgiving to the beginner. JBP have a completely different growth pattern than JWP. Scots, however, are very similiar.
