Weeds grow and eat purely based on the soil and the sun, unfortunately, they don't need both, they only need one. While they will always grow towards the sun, they don't require it to survive, which is why we are able to see them in the first place.
But in short, you will need to take out every aspect of the roots and seeds in order to get rid of the weeds. This is where the term seed bank comes in. The fact is that weeds have started to realize that we don't like them in our garden, so in order to survive they have begun leaving their sproutlings dormant all over the place. This means that there will always be the possibility of weeds anywhere.
So how do you get rid of them?
So if you cut a weed in half and leave it in the ground, it will grow. If you cut of both ends of it and leave a stalk there, it will grow into a new fuller weed.
To answer this question, we have to address the fact that short of completely eviscerating the species forever, it's impossible. You can get rid of every root in your garden or lawn and if your neighbor doesn't keep care of theirs, it will grow into your yard.
Weeds live underground and that is where they keep root. Weeds will branch these long veins in the ground and take root based on their seasons. Many common ones up here such as medusaheads and cheat grass are designed to stay hidden and dormant during the winter in order to survive. The idea is that each weed in its part will always be trying to grow.
Perennial roots have lots of energy in them from previous years of growth. Miller explained that energy helps the shoots grow very quickly. This makes perennial weeds particularly hard to control.
“The weed is able to grab those resources before the vegetable plant can get them, so they tend to grow a little faster and a little better than the vegetable does,” Miller explained.
The weed seeds are already in the garden soil. They wait for just the right temperature and moisture conditions. So, when you plant your seeds, the weeds race out of the ground before whatever you planted can even get started.
If you’re like me, you’ve picked up a little dandelion fluff ball and blown the seeds around. Weeds like these make a lot of seeds. They get picked up by the wind and planted far and wide. And as you observe, they grow pretty fast, too.
My friend Tim Miller is a researcher at Washington State University working to help stop weeds from making life difficult for plants we would rather have. Sometimes, weeds are bullies to other plants.
He explained that these plants compete for resources both of them need to grow: sunlight, water, nutrients, and space.
Miller said some weeds grow from a root that has been alive for many years. These kinds of plants are called perennials. The grasses in your lawn are also perennials. Perennial weeds grow especially fast and are much harder to kill than annuals, which have to grow from seed every year.
Dandelions are one kind of perennial. Each dandelion fuzz ball has as many as 100 seeds that travel in the wind. If a dandelion plant makes 10 flower heads, that’s 1,000 seeds waiting to sprout wherever they land. How many dandelions do you think you have in your lawn? If there are 50 plants, just think of those 50,000 new dandelions that can sprout from all those seeds. It’s no wonder weeds are so hard to control.
Sometimes gardeners help their vegetables by growing them in pots and then transplanting them into the garden. That gives the veggie a head start against the weed.