Hi there, I'm Christy Wilhelmi from Gardenerd. Have you ever experienced this: where your raised
beds do really well the first couple of years and then suddenly they just kind of stop working?
They stop growing. Things feel stunted and nothing you do seems to make a difference?
Well, I'm going to talk about the number one reason why that happens in urban environments today.
As a professional, one of the things I have to do most often is
figure out why people's gardens aren't productive, and the number one reason
that I come across in urban environments is tree root infestation. So, this tree back here,
that is a carrot wood tree, that has invaded my own garden. So I wanted to talk to you about it today.
Most of the time I'm a no-till gardener. I simply put a layer of compost on the top of the beds each
season scratch it in with my fingers and then start planting, because I don't want to disturb
the soil biota that has formed an entire ecosystem underground. Right Mittens. That's right, we don't
want to do that. But sometimes if left unattended tree roots from neighboring trees, especially from
hedges--privacy hedges like privet and ficus, which they're part of the same family, eugenia, a bunch of
other type of hedge trees, yew trees, pittosporum, they all come in and start...once they find your
raised beds, they start siphoning away nutrients and water and your beds stop performing. So let's
take a look at the difference between what roots look like that belong there and roots that don't.
When you pull plants out of your raised bed, sometimes, you know, and usually I recommend
just cutting off the roots and leaving those in the soil. Because of course there are a lot of
biology, fungi and bacteria, colonized around those roots and you want to let them break down and keep
feeding on those roots as they disappear. But sometimes especially if you've got root-feeding
nematodes which happens, Hi Mittens. It's a good idea to pull everything out. Now when you pull out
a regular plant the roots are going to look like this. You know, the roots are mostly large there
are fine root hairs but those usually break off in the soil and they are not uniform in shape.
When you look at this close-up of it you can see that the the root hairs are really random. They
don't have a uniform shape and they are easy to identify as being part of the plant that you grew.
Now when you look at tree roots, you're going to stick a digging fork in
your soil and rock it back, and when that lifts up [the soil] you're going to feel a whole bunch of roots
rip off from the bottom of the bed. And what they look like,
well, let me show you. I unearthed all of these roots from this raised bed last night. All of these
don't belong in this bed and the way you can tell the difference is that the the roots have a red
texture to them. They're much darker than the roots of your regular plants, and the thatch of fine
root hairs, as you can see here, are a really uniform all down the length of the the root.
These guys are sucking nutrients and water out of your beds, and it's important to
excavate them every couple of years to make sure your gardens will thrive.
Just stick your digging fork in and rock it back and you'll feel a lot of stuff unearth
from underneath at the bottom of the bed and when you take this you can see these are tree roots.
They're dark and they're attached at the bottom of the raised bed rather than having grown from
the surface. And so you can take a clump of soil and shake it out and, um, all these tree roots
will just kind of settle. They lose soil pretty quickly and you can take these out
and then you'll be ready to prep your soil and plant again. Sometimes if the problem persists
we have to go in with me and my crew, we go in we dig out all the soil, we put down a layer of
hardware cloth and and landscape fabric and then we return the soil. It's the kind of thing that
happens in an urban environment if you've planted... if you've put your raised beds right up against
or near within I'd say five feet or even more of a tree a neighbor's tree or a row of privacy hedges.
So this is the kind of thing that is fixable. It's just something to consider when you are figuring
out where to put your raised beds in the first place. There is one other reason why raised beds
stop performing and that is because you've got predatory nematodes, root-feeding nematodes in
your soil but that's going to be for another video. In the meantime you can go check out
the video on beneficial nematodes and learn how to apply them to your soil and then we'll
talk about this in another video. Thanks for watching. I hope you enjoyed it. If you like
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Grow Your Own Mini Fruit Garden and Gardening for Geeks. Thanks so much for watching. Happy gardening!