The first one-third of your description sounds very much like my situation. The rest though shows clearly that your situation is worse.
In my case, the neighbor with the pool has a huge (~300y old?) poplar at the back of his yard, which blocks a lot of sunlight. But he wanted more sun for his pool, so a major pruning job (~$600) started last weekend, and its making a big difference already.
Anyway, good luck to you....

That sounds very frustrating. Does the maple tree (and the unknown trees) actually have branches hanging over your property or is it just the shade the covers your property? If it is the former, by law you are allowed to prune any branches hanging over your property. In this case, I would suggest talking to your neighbour and seeing if you can get permission to get some branches back to the trunk (assuming the trunk is all on his property -- otherwise you don't really need his permission; but it is always better to discuss this first and see if you can reach a mutual agreement.) It is not cheap to hire an arborist to cut large branches back, but it is worth it if you can afford it. Maples are very robust and agressive and will eventually fill in again, but in the intervening years your plants will grow better with the dappled shade such pruning can give you (and the reduction in leaves -- and berries from the other trees -- will be good too.)
As for weeds, do you have room to plant something like a yew hedge along the boundary, or can you put up a solid fence. This won't stop the maple seedlings, but it will stop a lot of weed seeds that blow in. For those that travel by roots, the yew roots would create a barrier (I find Hick's yews grow fairly quickly given ample water and bone and blood meal).
I wonder if those unknown trees are buckthorns? Buckthorns (which grow happily under maples) are officially recognized as an invasive in Ontario. They usually only grow about 12 feet high (although I've seen some higher) and with pruning on your side and a solid fence, you could get rid of most of the fallout from those.

One thing about buying established properties, always look beyond your yard to inspect the surroundings.

I would always have a chat with neighbors about gardens etc.. It makes for a great cooperative relationship. Perhaps because your neigbor is elderly on possibly on limited income, he is unable to address the issues. You can talk about cutting out branches that fall on your side of the fence. I would also suggest that you install root barriers on all sides of your fence to prevent invasive plants from your neighbor's end to enter your yard. If you have problem with falling leaves, berries and debris, discuss this with a landscaper to see what they can suggest. I'm thinking of black fine nettings to prevent leaves from falling into your yard. But can it be done in an attractive way - like a trellis? You'll get a shady garden but in my opinion, it's nice to have a lush shady yard.

You didn't discuss if the seeds fell on grass or beds or patioed areas? If it's grass, then do as you do, which is to rake in the seeds and then use a lawn mower to mulch it further down. If its a patio, then sweep things away.

If you have unsightly views, then produce screens.

Ianna

Anyone thinking of trimming branches from neighbouring trees should check with their municipality first. It is not always the case that you are allowed to do this. In any event uneven trimming like this may destabilize a tree, and then you'll have bigger problems than falling leaves to deal with (and if your trimming of neighbour's trees contributes in any way to the decline of a neighbouring tree or plant you could be in for some legal trouble). Not to mention this doesn't do a lot for neighbourly relations - and being on good terms with the neighbours is worth way more than not needing to weed (and you always need to weed).

I do know how frustrating it is to have to pull out tree seedlings by the hundreds or thousands - I have three different trees raining their seeds onto my plants. I also have a very unsightly alley on the other side of a chain link fence, and I have had more than my share of 'black thumb' neighbours. I screen out the ugly alley with trellis attached to the fence, I pull tree seedlings by the dozens on a daily basis, and I smile and wave at the neighbours, and wish they'd learn to love a nice yard. That's the life of a gardener.

All nice gardens are a lot of work, all the time. You can never sit back and say "I'm done". Weeding is something you'll have to deal with, weather or not it is trees or dandelions - there will always be unwanted plants trying to take over the nice spot you have made. Sometimes you have to rework your garden plan to take into account other people's problems, but that's something that happens on an ongoing basis as plants mature and die in any garden.

One thing I would do is to ask the neighbour with the leaning maple if you could have permission to have it inspected by an arborist (not a landscaper that says he "does trees"). Some commonly planted maples are fast growing and get pretty big, but they don't have a huge lifespan. If this tree is nearing the end of its life you might want to have it taken down before it falls down (especially if it might fall on your house!). And this one is leaning? You might want to find out why.

If you're trying to protect an eating/sitting area from falling berries and leaves, you can make or have made some sort of arbour or pergola. You can use screening, bird netting or trellis on the top to provide some sort of cover that still lets in light. A solid roof will protect from rain too.

How much mulch do you have around your existing plants? And what kind is it? You want to have a lose mulch, like finely shredded bark (or shred those leaves you have so many of), and probably to a depth of three inches. You'll still need to haul out tree seedlings, but it's a cinch with a good layer of mulch. Ignore ones in a lawn - just mow them down when you cut the grass. Crunch up the seedlings in your hand and toss them in a compost pile - look at them as future organic matter that will benefit your wanted plants.

And finally, remember to sit there with a glass of your favourite drink and enjoy what you have! That'll give you the extra oomph you need to get the weeding and cleaning chores done :-)
BP

Euphemia, if life gives you a lemon, make lemonade! In the fall, don't rake the leaves, shred them if you can (a mulching mower does this nicely) and mulch your flower beds heavily with them. The leaves will compost down if the delighted earthworms haven't pulled them all into the soil by next summer, simultaneously tilling your soil for you and providing perfect fertilizer. At the same time, the mulch will smother any seedlings underneath it, and prevent most seeds on top from germinating. Those that do manage to sprout in the mulch will be very easy to pull out.

Those leaves are pure gardening gold, and you if you use them, you won't need to buy compost or manure. If you hate the look, you can cover them with either compost or manure to make it look like "dirt".

Personally, I go begging for bags of my neighbours' leaves in the fall, as the white pine overhanging my yard only provides needles. Leaves are the best soil amendment I have ever used.

Janet's Garden

My understanding is that the right to cut branches overhanging your property has been set by Canadian courts, not municipalities. However, municipalities often have additional by-laws, and I believe Toronto makes it clear that you cannot trespass onto your neighbours property without permission in order to cut the overhanging branches. If the tree leans toward your property, removing some branches on your side will likely make it more, not less, stable -- but an arborist will know for sure.

Yes, I believe we have similar bylaws here -- the arborist mentioned it, before I had the tree in my other neighbor's yard pruned of the branches overhanging onto my property.
But you certainly need to talk to your neighbor for access, because the arborist needs to climb the tree trunk which is located in the neighbor's yard.
In many cases, the neighbor will gladly grant that access -- they just don't want to foot the bill for the pruning.
I just got lucky with my neighbor with the pool, who decided to pay for the whole job himself, even though I offered to share the cost....

While you can (usually) safely chop off branches from shrubs or other small plants that intrude onto your property, many cities have slightly different rules for big trees - see here for Toronto. It basically comes down to needing permission of the tree owner, and making sure it's trimmed properly. If your neighbour is the decent type, he'll grant you access to the tree so that it can be trimmed, and then there is no problem. But if you have a neghbour from hell, then you'll have to fight it out with lawyers ($$$). You can't damage your neighbour's tree without the neighbour's permission, and improper, uneven pruning can damage a tree. Some cranky neighbours will argue any pruning at all is damage, and then you're back to the $$$ lawyers. So the moral of my story is to make sure your neighbour gives you permission :-)

Most sane people will allow a tree to be trimmed by a certified arborist, especially if someone else is picking up the bill. Hopefully the neighbours are sane! Most responsible people will pick up the bill for their own trees. Here's hoping even more the neighbours are responsible!

All this reminds me to get the key to my neighbour's back space. I have to take down a stupid weedy Norway Maple that is growing out from the foundation (we share the wall). I told the landlord about it three years ago, but he's done nothing about it. Idiot. It's now about 20 feet tall, and 10 cm thick, and doing god knows what to the foundation. It's also shading my tomatoes, so down it comes!

BP

Move. You are fighting a losing battle.
Durgan.

I so sympathize with your situation. Whenever I buy a house, the garden is always the first priority, there must be no large trees near my house as these are the only things that you cannot control. The weedy backyards or pools and concrete are merely aesthetic, but huge trees are not only a great expense (pruning, or cutting it down if it starts to die, seeds, leaves etc), but could damage your house in a storm too.
Like Durgan says, it's easier just to move :)

A friend in St. Albert (Alberta) was in a similar situation. After several years of this battle, he both gave up and won.

He gave up fighting the weeds and self-seeders and the whole my-place-must-have-a-lawn concept. And he won peace of mind and a gorgeous garden by getting rid of ALL the lawn and putting in some beautiful stone work (old brick, paving stones, rock walls, it's quite a variety) and switching over to a container garden.

Some of his containers are the size of my household flowerpots; others are big enough to plant a tree in. Some plants are in hanging pots. He has a garden that stretches from ground level to roughly 10-12 feet high (long tubs of morning glories and sweet peas grow up permanent trellisis to give him walls of flowers). The garden is a private oasis where you could forget he even has neighbors. He never mows. Weeding is minimal.

His perennials are in the biggest containers, and he covers these with a couple-three inches of wood shavings every fall. He rarely loses a plant (I lose a lot, and I keep mine in the ground). I was surprised to learn how well wood shavings insulate. I used them last year for the first time, and this year I have many flowering biennials.

Once I'm working again and we have some cash, I'm thinking of doing exactly the same thing to my own yard. His is so beautiful it makes me wonder why I'm doing so much work.

Yes, if life gives you lemons, you have the option of making lemonade. If that's what you want to do. Here's one possible recipe.

Merri