is it always best to cut of dead bit of plant? i was just wondering if it effected plant when you sell them or is it better to leave dead bits on?

The dead bits will often prevent your plants from selling, so it's best to remove the dead pieces when you find them

Ok thank you

It's much easier to do so if you use mods. There are mods on these forums.

If you are just starting out with the basic soil, water and pruning shears it may be better to wait until bud formation. The health of the plants is sorely impacted by pruning - watch the Health Meter. With upgrades it's not as noticeable.