Posted: 20/05/2015 at 21:26
Bamboo - think about it. Are you really going to move pots of Bamboo around the garden each Spring and Autumn? Pots are heavy at the best of times, and with a Bamboo in it, it will be very very heavy. Look for a Bamboo that will give you the height you want and which won't get interfered with by the tree. Have an idea of the line of sight between your neighbours house (windows and doors) and the areas of your house you want to be screened from and then somewhere in the middle will be where you want the Bamboo to be. You don't need to plant it in one large block - you can plant it in one or two or three areas, and breaking it up will be more pleasing to the eye.
Organic Matter - start with well rotted horse manure. Well rotted means being left from fresh of the back of the horse until the manure no longer looks like horse manure (i.e., you can't see any bits of straw in it). You can off course buy well rotted horse manure 'ready made'. Lots of garden centres sell bags of it 3 for 2. Its not expensive. If you're on clay, then the benefit of it will be to open up the clay soil and make it more easy to work with (i.e., not go rock hard in dry weather). Another good organic matter is spent mushroom compost. There are lots of suppliers around (look online), and its another way of loosening up the soil to make it easier to work with. There are also other things you can use - well rotted leaf mold but this can make your soil acidic. Great if you want to grow Azaleas and Rhododendrons.
Pittosporum should be fine in clay soil as long as the ground doesn't get waterlogged. I know somebody who grew a Pittosporum in really heavy clay that went rock hard in summer, but never waterlogged. It was over 12 feet and really healthy and strong plant.
OK - point taken about Yew - why tempt fate! And yes, all poisonous. If you are worried about having any poisonous plants in your garden, take a look thepoisongarden. You'll be surprised how many there are.
Pyracantha - can grow up to 12 feet in height and up to 12 feed wide. However, easy to control by pruning and trimming - just be careful of those very sharp thorns and make sure you pick up any that fall to the ground, especially on a lawn if you or family is prone to walking barefoot on cool wet grass!
Hydrangea - no, just keep pruned back to the space you want to grow it in. Just be aware though that its stem will thicken up over several years and it could bring the fence down under its weight. Make sure your fence is sturdy.
Robin's are the gardeners friend - its amazing how friendly they are. Whenever I am digging in the garden I have a Robin that comes down and picks up any grubs or bugs that get dug up. I'm afraid you can't stop the other creepy crawlies, and actually you need to encourage them to bring balance to your garden. Nature doesn't like void, and if you kill something, nature will just send more to fill the gap. Spiders trap flies in their web, bees pollinate the flowers to create seed, even slugs and woodlice are helpful - they eat and breakdown the dead plant matter. If you're going to be a gardener, you need to get used to bugs and creepy crawlies - sorry!
Yes, Hedera (or ivy) will be excellent for screening up and over a fence.
Photenia Red Robin - once it is established it will grow quickly. Mine has put up to 2/3 feet growth in one season. It seems to me it grows for most of the year, only stopping in really cold weather in the winter. And yes I like your idea about making it in to a standard (ie, removing the lower leaves). It seems to want to grow from a shrub into a tree anyway, so if you treat it like that, you'll be fine.