Another question in the Inbox that I can relate to – how to get rid of bedstraw and bindweed. Both are annoying as they climb the trees and interfere with other things you are trying to do.
Bedstraw is possibly easier – there are 2 primary kinds that I see – and they seem very prolific this year.
Smooth bedstraw (Galium mollugo) has white flowers, 8 leaves at a node and smooth stems. It is perennial.
https://www.oardc.ohio-state.edu/weedguide/single_weed.php?id=4 The pictures aren’t great but the information is good.
Catchweed bedstraw (Galium aparine) looks very similar but has hooks on the stems and leaves, leading to another of its names, Sticky Willy. It is an annual – sounds good, only lives one year – but wait, the seeds are prolific and they stick, too, so it is easy to spread it around on clothes, fur, feathers, equipment… https://plants.ces.ncsu.edu/plants/galium-aparine/
We are a little late on bedstraw – in Ithaca anyway – as it has gone to seed and is likely to be spread while removing it. Try and get it out of the field – particularly the annual sticky one – when it is in flower or before (the flowers make it easier to see).
From the Guidelines – and only G. aparine is listed but it is likely that G. mollugo is affected the same way –
Pre-emergence – Goal 2XL – a good idea where you have had the annual one the year before
Post emergence – Goal 2XL and Roundup Pro (or equivalents)
There is more than one bindweed, too – most commonly Field bindweed (Convolvulus arvensis) and hedge bindweed (Convolvulus sepium). Both are perennial – and have taproots so they are very difficult to eradicate. This is another of those weeds that are best controlled in the late summer. They need to be actively growing but at that time, the herbicide will be translocated to the roots, giving better control. It may still take several years.
I have an ID comparison if you are interested – too big to send on this listserv or you can look here under concolculuc – https://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification.aspx
Convolvulus species is listed in the guidelines
Post emergence control – Finale (glufosinate ammonium) and Roundup Pro – both are non-selective meaning they will damage nearly all plants.
However, the question was how to control them without hurting the trees. The only way is to use a directed spray and not contact the trees. Often the plants that are most problematic are literally entwined with the tree so no contact is almost impossible. Shielded sprays and sometimes just cutting them out, as well as trying to control them before they get too big will help. Trying not to let them go to seed helps in the long run.
Have a great evening!