What’s your go-to source for gardening advice?

I have that one and also their Encyclopedia of Gardening and they are excellent reference books.

I would strongly support a Conversation to discuss the problem of gardening chemicals. The RHS provides a list of the more recent ones that have been banned: https://www.rhs.org.uk/advice/Profile?pid=820 It is disappointing that the list does not include products that were withdrawn earlier in their sheds. Take calomel dust as an example. It was withdrawn about 15 years ago. One pack of this contains vastly more mercury than any compact fluorescent lamp.

Chemicals that are effective at controlling pests and plant disease are not specific and will also harm beneficial species including bees, the example given by Patrick T.

In theory, recycling centres should accept chemicals and dispose of them appropriately but I am not convinced that this is done properly.

“CFLs contain a very small amount of mercury (around 5 mg), which is approximately 100 times less than the amount of mercury in an oral thermometer and roughly the amount that would cover the tip of a pen.”

There is a move to restrict sales of domestic pesticides and weedkillers in their fully-diluted form only to prevent the dumb public from using them incorrectly. Anyone who has bought fully-diluted products will know the extortionate cost. Perhaps washing up liquid will only be sold this way – ready to fill the bowl and wash your pots – in 100 gallon containers? It is a pity that some have such a poor concept of our intelligence.

I suspect that the high prices of ready to use domestic pesticides and weedkillers is partly due to profit margins but if the increase in cost cuts down use there will be an environmental benefit. I don’t think it helps to refer to the ‘dumb public’ but there is little doubt that garden and household chemicals do present dangers. I was particularly glad to see paraquat banned because of the incidence of respiratory damage, but acute toxicity was only one of the problems.

Perhaps the best approach is to grow plants that flourish without use of pesticides. Back in the eighties I sprayed my roses in a not very successful attempt to control black spot and greenfly. A botanist pointed out that some roses are less susceptible and bought me three as a birthday present. That proved very successful and I gradually replaced the other roses over the next few years, starting with the ones that were worst affected. My father was impressed because he had struggled with the same problems for years. If the grass has a few broad leaved weeds, there is no need to treat the whole lawn, since a pinch of weedkiller or a quick squirt with ready-made weedkiller is all that is needed to keep it weed free. A daisy grubber will remove some weeds without using any chemicals. Fruit and vegetables are more of a challenge but simple crop rotation and selection of varieties that are more resistant to pests and disease will help.

“I don’t think it helps to refer to the ‘dumb public’ “. The vast majority are far from dumb, perfectly capable, and I don’t like to see regulations being framed as if we all were brainless. Life is full of possible dangers that we all, generally, cope with – from crossing the road, not sticking knives in toasters, to reading instructions om how to use products.

As for my lawn, it is a mixture of grass, moss, clover, weeds and it never sees any weedkiller – a weeding too;l easily lifts out dandelions and thistles in their early stages. But it looks decent when I mow it, and it is green.

Compost is one area Which? regularly examines. However it does not seem to look at – or at least mention – the composts that professional growers and nurseries use. They will have a better insight than anyone into what is good, I would have thought, since their businesses depend upon good growing media. Are the products available to all the public, and what are they?