As gardeners and garden designers, we see a lot of weeds during our working week.
At Plews, we generally categorise a weed as being an invasive plant in the wrong place, able to be both annual and perennial.
Our ‘most wanted’ list includes ivy, bindweed, dandelion, nettle, green alkanet, bramble and ground elder.
These are all perennial weeds with strong root systems, which is why they’re successful at colonising less cultivated areas of a garden, and why they’re difficult and time consuming to get rid of.
We’ll be looking at all of these weeds in various blogs; this time we’ll consider the two climbers, ivy and bindweed.
Ivy, Hedera helix
Ivy, Hedera helix, common or English ivy, is native across much of Europe and is often grown as an ornamental. Its berries are a good winter food source for many birds and the flowers are nectar rich.
So why is it a weed? In many parts of Australia and the USA it is labelled as an invasive species; in the states of Oregon and Washington, sales of it are banned and it is listed as a noxious weed – as Japanese knotweed is in the UK.
Ivy is a survivor, it can spread easily through seed dispersal (birds and small animals are the main agents here). The stems have short root like growths but these only enable it to cling to tree trunks, fences and so on.
Although it is not a parasite, the density of growth is what causes the problem. The thick cover of ivy covering the ground prevents other plants from taking root and growing and it has the ability to spread quickly over large areas.
Kept in check in a garden situation it can be beneficial, offering evergreen cover to disguise ugly vertical spaces and shelter for wildlife.
Where an evergreen, shade loving climber is needed, there are some variegated ivies, for example, Hedera helix ‘jesters gold’, which will work. The trick is to make sure it is not allowed to take over fences or trees.
Ivy can also be used as ground cover; just be aware that it will root and therefore spread easily.
Spraying with weed killer can be tricky as the leaves have a waxy coating. Spraying on a cool day slows down evaporation, allowing more time for the herbicide to sink into the leaves. Making multiple cuts in the stems will also aid penetration of the weedkiller.
Where the ivy is climbing on trees, fences and walls, the best method is not to spray but to cut through the stems as low down as possible. This obviously kills the top growth which can then more easily be removed without damage to the tree, fence or wall. The stump can be treated with weed killer – organic or synthetic. If control rather than eradication is the aim, allow the ivy to regrow and restrain the new growth.
Bindweed, Calystegia sepium
The bindweed mostly found in gardens is Calystegia sepium, hedge bindweed, rather than Convolvulus arvensis which is the field bindweed. Convolvulus arvensis has smaller, pink tinged flowers as compared to the white flowers of hedge bindweed. You’ve probably seen it when on walks in the countryside.
A pretty looking climber, the common name ‘bindweed’ gives the clue as to why they’re not good to have romping through your borders!
The stems can strangle clematis, sweet peas, French beans and the new growth on shrubs.
There are different methods of removal, but these will take two or more years – assuming that the bindweed isn’t coming into your garden from a patch of wasteland the other side of the fence. A week’s holiday could mean you return to bindweed as an uninvited guest. But don’t be disheartened.
Bindweed is tricky to get rid of because it entangles around other plants, and a quick yank can pull up your pea plant as well as the bindweed. A better ploy is to snap the stem off near the ground, let it wilt and loosen its hold and then gently pull. Even then you may need to break the stem in a few places if it’s seriously intertwined with your wanted plant. Watch this YouTube video for some hints and ‘how to’ techniques.
The bindweed roots are white, regenerate from the smallest of pieces and may go down as far as 15 feet. Digging them out of an otherwise uncultivated border can take some time, but is worth the effort. Once you’ve dug up as much bindweed roots as you can, lay membrane over the area. You’ll need to revisit and repeat, but it will have an impact and reduce the bindweed incursion.
This is fine for a border which is not otherwise being cultivated for productive or ornamental plants. But what if you spot bindweed growing through your forsythia, sweet peas or runner beans?
Painting the young leaves with an organic herbicide early in the season is a start; as is vigilance to pullout stems as soon as they’re spotted in the border.
Where the bindweed is coming from a neighbouring garden or wild area on the other side of your fence, a good trick is to put sticks in the ground next to where it’s coming in. The bindweed will twine around the sticks making it easy for you to see and remove it.
The pulled up and dug out stems, leaves and roots can be turned into a compost tea but remember not to put them directly into your compost bin!
Related Gardening blogs you may enjoy