Block paving - How do I weed it?
Dinah
Posts: 294
The Problem: I rent a lovely house with a lovely garden and a fantastic view. I tend the garden, and love every minute of it, but the block paved yard and driveway tortures me to distraction 
Things That Don't Work: Pressure washing it just seems to blast the sand out, so that more debris gets washed down under the blocks, and with it more seed. The roots never, ever come up easily from between the blocks. Removing moss and small weeds with a manual scraper, or wire brush, supposedly designed for the purpose, takes about 5 weeks, and the weeds are coming back at the other end by the time I've finished, so it's back breaking and heartbreaking both at once. Weedkiller dosn't seem to work very well, perhaps it is all going between the bricks but not spreading out in the roots underneath, and the one that goes in through the leaves and then down into the root only works on the seeds that have sprouted enough to take it in, while the others come shooting up within weeks of the gap becoming vacant, so ends up very, very expensive. Special coatings are way above my budget if they will have to be done every few years. Lightweight "weed-wand" burners are just too small and light for our huge expance of block paving.
A Possible Solution? I've heard rumour of people hiring big, push along, tarmac burners to scorch the weeds between the bricks to death. I assume they must mean the smaller ones that are normally used for re-surfacing pavements and park pathways, rather than the huge ones you see driving along the road. Problem is I don't know where to hire one, and can't find any on an internet search. This is largely because I don't know the proper name of these elusive devises
- Please, dose anyone know 1) what they are called, 2) if they work, and 3) are they incredibly expensive to hire??? Any information would be welcome.
Posts
Spraying it is the easiest. You can get some that keeps the paving weedfree for a long time.
I use Pathclear or similar diluted in an old bucket and use a stiff yard brush to brush it on the drive, I find it easier than spraying and the determined weeds get a good scrub to make sure they absorb it.
They are called 'flame guns' and you can hire ones with 3 or 4 heads, which will clear an area about 2-3 feet wide in each sweep. They are cheap to hire.
I would have thought that weedkiller is your best option unless (as Pansy has already said) the area is sloping so the liquid just runs off.
Assuming the area is reasonably level - I would grit my teeth and let the weeds come through for a few weeks so there is a bit of growth. I would then apply Path Clear - this has a residual effect & helps prevent seeds germinating. Use the concentrate (rather than ready mixed) & apply using a large sprayer - you can cover a large area fairly quickly. Choose a day when it's a bit overcast but no rain is forecast (& no wind of course) - I often do mine in the evening.
If you use Path Clear you can spray all the grout joints (even those that appear 'clean') as well as the weeds to try & stop seed germination. The weeds should start to die within a few days. I would then leave it a few weeks and respray if weeds start to germinate. After that I would check the paving and regrout any areas where there are holes and gaps for weeds to set up home.
Glyphosphate / systemic weedkillers are excellent for killing weeds in ground that will be cultivated but only works on plants with green foliage. It doesn't stop seeds germinating & it becomes inactive when it comes into contact with woody stems or the soil. I would only use that on the persistent weeds you think are growing from under the paving itself once you've tried the above.
I find I need to apply Path Clear about 3 times between early spring and late winter on my gravel drive (aka a "weed seed tray").
I have tried using the nozzle of my steam floor cleaner to scald the leaves of the weeds but it was not very sucessful.
'You must have some bread with it me duck!'
That's lots of useful advise. I will battle on whatever with the weed killer, and I'll try the dissolving it in a bucket and agitating it in method (it is always too windy up here on the mountain for spray) and I will wait until they spring up in full growth to do it.
First, I will try hiring the "Flame Gun" with the multi-heads though, since I love the smell of toasting weeds
and the broad sweep sounds magical! Many thanks for supplying the name Bob, I'm surprised I never thought of it.
I have something that has a sort of wateringcan nozzle on the end, and you pour it over the area.. and it's supposed to be weed free for six months. So not really a spray, more of a root/soil treatment. I think it's made by Roundup? I'll have a look when I'm home.
I just looked it up online, it's Ortho GroundClear. Good for up to one year (whatever that means, those sorts of statements drive me nuts).
Just sprayed half of mine, but hand hurts too much now to finish it