Ask Gerry

This revolting slimy algae is forming on gravel/stone surfaces ~ pathways, carparks, cobbles. We think it's Nostoc. First (modest) appearance was in 2010; now it's widespread, sometimes in carpets up to 1.5cm thick (and counting).. Thrives on rain, even in this cold weather. Very unsightly, dangerously slippery underfoot. Can you suggest a chemical for control / elimination? (Drainage not an option) . (These Photos is from web; not my own.

I am starting to build my patio and want to dot some plants within it as it is quite large. I would love to plant a Clematis over a large rock in a squared off area covered with chippings. I have several clematis is mind as I would like a strong grower and perhaps one that blooms twice a year. My collection at the moment that I can use are,Sunset, Henryi, Piliu, Nelly Moser or the President. There might be some better ones but you would you recommend either of the above.

We have a footpath outside our sliding doors. We want to lay a patio. Is it possible to pave over the footpath and continuing paving onto the "grass" area to make the patio larger? Is it likely the slabs on the "grass" area would move over time causing cracking between the slabs set on the "grass" and the footpath?

Can you please help. I have dark algae on gravel and can get rid of it. Swells up in wet conditions. qite slippery. tried weedkiller, mosskiller, lawn sand, and mogathon- No good. Have tried picking it up but very slow process. any suggestions?

I have an issue with the location of my garden shed. It's in a north facing garden and we put it at the back of the garden but facing the patio doors (on the back left of the garden, west) The reason for this is the sun lasts longer in the evenings on the right, east. Now we're thinking of putting down a patio and I don't know whether to put it near the house by the patio doors or at the back of the garden. What would you recommend I do with the shed, do you think it's unsightly to have it facing the patio doors, especially if we put the patio in front of it. What options do I have as I haven't a clue what to do. The shed is 10' x 6'. The garden is approx 32' x 25' Thanks very much.

My enclosed patio measures 12ft wide by 23 long. My sitting room faces onto it. It has a wooden railing along the front. A sun room faces onto one side and a low red bri ck wall makes up the 4th side. It is paved with ordinary grey slabs, not in great condition. Unfortunately it has a washing line, tho it is removable and a built in barbeque, wooden rectangular table and chairs. I feel I could do a lot more with the space and like the idea of Japanese planting. It is south facing.Because it's narrow, I'm not sure how to manage the space. What plants are suitable, eg would bamboo be okay in a container in a sunny position? Needless to say, am on a budget!

I'm looking for about ten large stepping stones in random (circularish or oval) shapes approximately one metre in diametre to creat a pathway. I've tried all of the large quarries have been unsuccessfull to date. Can you please let me know if you know where I could try to find the stones? Many thanks,

I have red and black patio slabs in my garden and they have faded to a very dirty colour even though they are well looked after . any suggestions on how to get the colour back ie paint ? also i have a wisteria 4 years and still no flowers.

I am having trouble with moss continually appearing on tarmac & paths even when treated with proprietry brands Are there any more powerful & longlasting chemicals which kill moss and then have the same effect as simazine in stopping moss reappearing.

Can you please tell me what I should use to remove algae from pebbles I have along paths and driveway ?

My father is eldery and has decided to lay stone chips down on the grass to save him having to cut the grass in the future. The level of the grass in terms of the pathway is low enough that we don't have to take off the top layer of grass. QUE: Should we kill the grass before we lay the horticultural fleece and if so, what should we use? It would be the intention in the Spring to cut holes in the fleece and plant shrubs.

Over the past couple of years I have noticed a brownish slippery substance on my 'tar and chips' yard and paths. this has increased 200% this year and is very obvious when the ground is wet. It seems to shrink when the ground dries. In time it turns to moss and looks terrible. I cant brush it off as this removes the chips. Is there any treatment you can suggest?

I would like some help or advice on how to get rid of moss from a pavement. i would like to permanantly remove this moss. i've tried some products from various garden centre's and applied as advised but they have only removed it temporarily.any help or advice would be appreciated

I am paving the entire of my concrete rectangular yard (15' x 6') with paving slabs. I have read the paving section but am wondering if I can lay the slabs on sand as I'm hoping to do the work myself and would be nervous about getting involved with concrete/mortar.