If dandelions were difficult to grow I am sure we would all have pots of them. And if common bindweed (calystegia) were killed by frost I am equally sure we would value it as an ornamental. But, as it is, I would rank it as the worst of all weeds we have to tackle. Ground elder is bad, but it keeps low and it is possible to spray it off under shrubs. (I apologise to those who do not want to use chemicals in the garden and I prefer not to, but there are a few places where I will, carefully, use them and the control of perennial weeds is one of them.)
Ground elder is at least low and it will not smother shrubs. There are even variegated forms that I have planted and valued, as fine ground cover. But bindweed is far more serious. It twines up shrubs and smothers them, literally preventing light getting to them and killing them. While it is doing this it spreads under ground by long, persistent stems that can survive for years under weed-suppressing carpet of mulches.
So, I use weedkillers containing glyphosate in my battle against bindweed. Glyphosate is absorbed by the leaves and move into the roots where it slowly kills the plant. How quickly it works depends in the plant and the season. Some formulations have additional chemicals that give a quicker visual effect. But now is a good time to apply, as the weed is still in leaf but preparing for an autumn shutdown. It is most effective when applied to weeds in full leaf – there is no point spraying the soil and a few emerging shoots.
The problem is that glyphosate will kill any green plant it is sprayed on. So if the bindweed is growing through outer plants it must first be unwound, then placed in a black bag, still attached to the root, so you can spray it without getting any spray on valuable plants. Once dry you can remove the bag. You should see some yellowing within a week at this time of year.
You can also buy glyphosate as a ‘wipe-on’ formulation and this is effective but it does take ages to wipe all the leaves on bindweed smothering a rose bush!
All garden chemicals are controversial and some people avoid them entirely. But I think it is unfair to new gardeners to be too proscriptive and say that weedkillers are off limits. I can think of nothing more effective to put someone off gardening than to say they can’t use glyphosate on a newly acquired piece of land covered in weeds. I was recently criticised for suggesting the use of glyphosate in a garden column (I did recommend handweeding first). I agree that it would be best not to use any chemicals but, in my rural garden, where farmers spray hectares of land with the stuff, I do not feel guilty using it on a few square metres.
And things are better than they were! The stuff we used to sell when I was working in the 80s at Nags Hall are now banned. Paraquat was the main weedkiller – that was used to burn off annuals weeds. But it is highly toxic and we are better off without it. Hoeing is far better for annual weeds, and keeps you fit.
Of course, weedkillers are not the only garden chemicals we may use. There are pests and diseases that may need control. But we tend to have a more tolerant attitude now than 40 years ago and know that we do not have to spray everything. Many problems can be largely prevented by good cultivation and, increasingly, there are resistant plants that are less often affected.
Jobs for the week
This is the perfect time to sow a new lawn or sow seeds on bare patches. Cover sown areas with fleece to keep the soil moist and prevent birds eating the seed.
Scarify the lawn, raking out dead grass and moss and apply an autumn lawn food.
Autumn is a good time to plant and perfect for planting shrubs and perennials
If you hanging baskets and pots are looking tired, don’t be afraid to change them a bit earlier than usual. Early planting allows plants to get established before winter and that benefits flowering plants such as violas. There are lots of small plants that look good in autumn and winter including small cyclamen and colourful heucheras.