Alina W

Is ivy a good thing or a bad thing?

I'd agree with the earlier comments - it needs keeping in check.

Definitely keep it off your trees, because it will kill them. Don't let it roam free in your garden, either, because it will strangle other things and eventually get so established that it'll become a serious nuisance and almost impossible to remove.

Hanging basket in shade

Busy lizzies and begonias do fine, as will ivy-leaf geraniums if you plant two baskets and keep one in the sunshine - swap it with the one in shade every couple of weeks.

Dahlia grown from seed

Yes, I'd agree. They need to be going outside now to start flowering soon.

Advise needed

I would have thought that annual bedding plants would be perfect for you - things like lobelia cascading down the sides, and shorter flowering annuals, such as alyssum or the shorter bedding asters, on top.

lilac tree cuttings

Does the tree have no suckers coming from it? They would be the easiest way to get a cutting, unless it is grafted.

Seeds & cuttings on a windowsill

The reason that your seedlings and cuttings are so poor is indeed the atmosphere. Growers can give their plants ideal conditions, whilst yours have had poor light and been too warm on top of the radiator - that has encouraged them to grow lanky.

Before puting them out in the garden, you should have been putting them outside on warm days and bringing them in at night - that would have helped them to thicken up. You still need to do this before planting them out now, for at least a fortnight.

Once your fuchsias are outside, they will improve considerably, and you should find that they (and most of the seedlings) will give you a good show.

Hosta flowering - shall I or shan't I?

I leave mine to flower, as well, and it certainly hasn't affected them adversely as two are over five feet across!

It is true that they flower very late (or mine do, anyway) and the dying flowers do signal deteriorating leaves, too, but since that's usually late September it's not a problem.

Are they weeds or are they poppies?

If it is the Welsh poppy it can turn into a nuisance, as they're difficult to weed out (they re-grow from scraps of taproot). They like acid soil, and will grow in sun or shade.

Cactus or.....,....

If the window box is outside, they wouldn't survive the cold, either - they don't survive frost, and don't like being wet.

Morning Glory

I wouldn't pinch out Morning Glory myself - I've found them to only produce a single shoot to replace the one taken out, so all that happens is they're slowed down.

Very many modern seeds will bush on their own - last year, and awful lot of things were spindly because of the poor summer.