The most problematical garden weed that I am familiar with, could quite easily be the star of some dreadful sci-fi horror movie. Commonly known as Dodder, its botanical name is Cuscuta. Originally from North America, it has spread to Europe, the Mediterranean countries and beyond. If you've ever seen yellow or reddish string-like filaments, wrapping themselves around low-growing plants, then you'll know what I'm talking about. Cuscuta has been known to ruin complete crops - it could ruin your garden.
To understand just how creepy Dodder is, you have to know how it grows. Cuscuta is a parasitic plant, that twines itself around host plants, and by way of suckers, draws water, mineral and organic nutrients from the host. It spreads from host to host, by the afore-mentioned, thin filaments, which elongate continuously throughout the summer growing season.
As rapidly as it spreads vegetatively, it flowers and sets seed buy weed in Europe with incredible vigor. After dispersal, the seeds germinate on moist ground, whereupon the seedling "looks for" a host to parasite on. This is the only stage in its life cycle when it is capable of independent existence, for as soon as a host plant is found, its roots die, and from that point on, as a parasite, it lives entirely off the host. What a pity Alfred Hitchcock did not make a film about this plant!
Which of your garden plants are vulnerable? Cuscuta will parasite on virtually all herbaceous plants with the exception of grasses, as well as sub-shrubs and semi-woody plants. Fortunately it cannot climb up trees or shrubs.
Within just a few days after germination, the Dodder filaments start to grow on neighboring plants, providing they are suitable hosts. Unless acted upon very quickly, the whole flowerbed can be smothered. It can happen after less than two weeks of neglect. Therefore, at the first sign of infection, it's necessary to cut the host plants down to the ground, and to collect and burn them. There is no point in trying to separate the garden plant from the Dodder, for from the tiniest fragment left on the plant, the filaments will rejuvenate almost immediately. Neither should the refuse be thrown on the compost pile, because Cuscuta seeds are hardy to the temperatures of even the steamiest pile.
As with most things, when it comes to weed control, prevention is better than cure. If Cuscuta is known to be a menace in your area, do not plant a garden bed before soaking the ground before hand. If Dodder seeds are present in the soil, existing weeds will be parasited very quickly. On the other hand if the area is clear of weeds, Dodder seedlings will die, as their existence, independent of a suitable host, is very brief. Secondly, always buy compost and plants from reputable suppliers and garden centers, as cheap, unreliable establishments, could easily be the source of the dreaded Dodder weed finding its way into your garden.
My name is Jonathan Ya'akobi.
I've been gardening in a professional capacity since 1984.
I am the former head gardener of the Jerusalem Botanical Garden, but now concentrate on building gardens for private home owners.
I also teach horticulture to students on training courses.