Identifying and Controlling Persistent Weeds in the Garden - Ep. 149

Karin Velez [00:00:01]:

This is positively farming media. I spent the better part of my afternoon on Monday pulling Johnson grass from my tomato field and in between my pole beans, which is what prompted today's episode. Welcome back, my gardening friends, to another episode of the Just Grow Something podcast, where we're going to talk weed control, specifically, persistent weeds. That Johnson grass is a perennial weed that reproduces both by seeds and by rhizomes, and it's been an aggressive problem for us in one particular field. Its little buddy field bind weed, was the focus of most of my eradication efforts a few years ago until we got that one under control, and now my focus has been on the Johnson grass and another pest poison hemlock. Yeah, we get all the fun ones here today. We'll talk about knowing the difference between annual weeds and perennial ones, the different ways they spread, and some strategies on how to prevent and control them. In most cases, you are not going to eradicate them completely, so managing them is the name of the game here. In some cases, this could take years, and the frustration level may make you just want to give up. But trust me when I say even the heaviest weed infestation can be controlled with a plan. Let's dig in.

Karin Velez [00:01:23]:

Hey, I'm Karen, and I started gardening 18 years ago in a small corner of my suburban backyard. When we moved to a five acre homestead, I expanded that garden to half an acre, and I found such joy and purpose in feeding my family and friends. This newfound love for digging in the dirt and providing for others prompted my husband and I to grow our small homestead into a 40 acre market farm. When I went back to school to get my degree in horticulture, I discovered there is so much power in food, and I want to share everything I've learned with as many people as possible. On this podcast, we explore crop information, soil health, pests and diseases, plant nutrition, our own nutrition, and so much more in the world of food and gardening. So grab your garden journal and a cup of coffee and get ready to just grow something.

Karin Velez [00:02:07]:

Quick reminder about our 50K giveaway of a $50 prize package to celebrate 50,000 downloads of this show. Don't forget to get your entries in doing one or all of the following tasks share your favorite episode or just a recent one on your social media with a few words saying why you enjoy the podcast. Be sure to tag me so I can see it. This is one entry. Leave a review on Apple Podcasts, Audible, Pod, Chaser, or any other app that allows for reviews. If you leave it anywhere other than Apple podcasts, be sure to let me know by messaging me in some way. If you've already done this, you already have an entry for this task. This is entry number two, and for those of you not on social media, or not using an app that allows for reviews. Or if you just want a third entry, send me an email or a message telling me what you like about the show or a specific way the show has helped. This is entry possibility number three. 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I also encourage you to jump into the Just Grow Something Gardening Friends Facebook group and post any questions you have, or just share pictures of your gardening journey as you go through this first year. We've got a bunch of gardeners in there ranging from brand new to 30 plus years of experience in all different zones, and everyone is just super helpful when it comes to answering questions. I'm in there every day answering questions, too. And before we get into the weeds, I want to welcome Chris K to the Patreon community. Chris joined at the seed patron level and now has access to all the additional content over there every week. If you'd like to see what's going on over there and support this show monetarily starting at just $2 a month, head to patreon.com justgrowsomething or click on the link in the episode description or in the show notes to get more information. Thank you, Chris. Your support means the world okay, let's get into weeds. First of all, we need to know the difference between annual weeds and perennial weeds. This is the exact same difference that we have with any of our other garden plants. Annual versus perennial. Annuals are those plants that complete their life cycle in one year or less. Now, the important thing to remember about annual weeds is that they usually produce a large number of seeds that can germinate very quickly and spread very widely. So some examples of annual weeds are things like crab grass, chickweed, lambs quarters, and purslane. Now, the important thing to know about annual weeds is that you absolutely want to prevent them from flowering and spreading those seeds again. That is how they spread, and the seeds can remain dormant as well. So just because you pull them all even after they have seeded, doesn't mean that you got them, those seeds can sit down there. And there are some annual weed seeds that can remain dormant for up to like 30 years. So this is just one more reason why we don't want to be disturbing the soil any more than necessary, because what we're doing at that point is we're bringing those dormant weed seeds up to the surface, exposing them to sunlight and terrain and all that kinds of stuff, and then they want to sprout. Now, perennial weeds are plants that live for more than two years. They have very deep root systems or underground sort of systems of stems or roots or rhizomes that can store food and water, that allows them to survive harsh conditions, to die off and remain dormant over the winter, and also allows them to regrow after being cut or pulled. So some examples of perennial weeds are things like dandelion bind weed, nut, sedge thistle, and of course, that Johnson grass that I mentioned. And there are biennial weeds, say, things like mullion, but we just sort of classify these into the perennial category because the methods of removal are pretty much the same. Now, is it necessary to know exactly what weed it is that we are dealing with? Well, yes and no. I had an old timer tell me once that the weeds that I was dealing with were shattercane, which is an aggressive weed in its own right, but it is an annual. What I've really been dealing with this whole time was a lookalike to the shattercane, the Johnson grass. So if I had tried to manage the Johnson grass as an annual based just on what I was told, well, then I likely wouldn't have made any headway on it. But when I started pulling the weed from my garden beds, I recognized that it had rhizomes, which meant it is definitely a perennial, not an annual. So it's helpful to know what the weed is in the case that if these things are dangerous to handle, like giant hogweed or poison hemlock, but just knowing the signs of whether it's a perennial or an annual is more likely to be helpful. When we're talking about eradication. If you want to know exactly what you're dealing with, there are often lists of your local common weeds on your department of conservation website. Local university extension websites there are weed identification links on university websites based on region and you can also use Google Lens to just take a picture of the weed and do a search that way. Now, another way to identify them is to find something in your garden that you're growing intentionally that looks similar to the unwanted plant, whether that's based on its leaf growth or its flowering pattern. And you'll get an idea of the plant family it belongs to, which will give you an idea of its growth habit. So, for example, field bind weed is in the morning glory family and the flowers look almost identical. Johnson grass is a sorghum, and the seed heads look very similar to the cultivated types. Purslane is in the porchulaca family, just like the decorative ones that we plant in hanging baskets and put into our flower beds. Now, it bears noting that some of these weeds, and I'm using air bunnies here, are often a forager's dream lamb's quarters. And perslain are very prized. Edibles cleavers are used for cleansing the lymphatic system. Dandelion has a ton of good properties to it. Mullion is medicinal, so do with that information what you will. I typically allow perslain to do its thing in my garden because I harvest it and I eat it in salads and I use it in green smoothies, but others just see it as a pain in the Tucas and they pull it immediately on site. So what you consider a weed may differ a little bit from what your neighbor views as a weed. So whether they are an annual or a perennial, both these types of weeds can be persistent in the garden and they sometimes require different strategies to control them. So here are four steps that you can follow to control persistent weeds. Regardless of whether they are annual or perennial, the first thing to do is to mulch over them. Yeah, come on. If you have listened to this podcast for any length of time, you knew I was going to mention mulch here, right? Mulch is that layer of organic or inorganic material that covers the soil around our plants. It helps retain moisture, it prevents erosion. If you're using something organic, it improves the soil quality and it is going to suppress weed growth. So you can use shredded leaves, cardboard, straw, wood chips, even commercial compost. As mulch, this is generally what I do. Apply a thick layer of it. You want a minimum of two inches around your plants and in between the rows. This is going to prevent most annual weeds from even germinating. And it makes it easy to see any new weed seeds that kind of blow in on the wind if they do manage to sprout on top of the mulch. And it also makes it very easy to pull them at that point. Now, for perennials, mulch can sort of help to choke out the species that are the very least aggressive in their initial growth. But you will need a very thick layer closer to four inches. And most perennials have very extensive root systems, which means they have a lot of energy stored up to help them push through many layers of dirt and our mulch. But the mulch will make it easier to spot these weeds as they push through and easier to pull them as they do. After doing this over and over again, you will have exhausted the energy reserves of the root system and the weed will eventually die off. But persistence is key here. If you let them go even just once for too long after sprouting, then they're going to put more of that energy back into those storage organs and the cycle will continue indefinitely. So you have to, have to, have to stay on top of it. As we head into the summer heat, our garden plants may need a little help to get through. Now's the time I start using my bloom juice from Elm Dirt as a foliar spray in my garden for all my flowering and fruiting plants. Elm Dirt has a new code for.

Karin Velez [00:12:24]:

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Karin Velez [00:12:25]:

One, get one free offer. Just go to justgrowsomethingpodcast.com dirt and use Code WolfCreek. All caps, all one word at checkout and get your second item of equal or lesser value for free. Justgrowsomethingpodcast.com dirt with Code WolfCreek. The link is in the show notes. Now the second thing to do is to exclude the light. So for persistent weeds, especially perennials or a high volume of weeds, you need to deprive them of light completely. This is going to weaken their root systems and prevent them from re sprouting. Now, a good way to do this is to use dampened newspaper or brown cardboard to cover the soil around your plants and then cover that with a thick layer of mulch to hold it in place. Another way to do this is to cover the entire bed with black landscape fabric. Now we're talking the heavy grade stuff here, not that paper thin stuff that you find in the garden center. This is that thick black plastic type that's kind of woven so it allows the moisture to get through, but it excludes the light and it gives a physical barrier. This works fantastically well for an area that has a ton of annual weeds that were maybe brought to the surface by tilling. But unfortunately, some of the toughest perennial weeds like Nut Sedge and Johnson grass will perforate the black landscape fabric. So mulching over top of the fabric with straw or something else may also be necessary. If you've got sort of a bad infestation with perennial weeds, it may take a few years to choke them out completely and we have to be vigilant in pulling them when they appear. Speaking of pulling them, that is tip number three pull them out or dig them up. Sometimes the best way to deal with weeds is just to remove them by hand or by using any myriad of tools available for this purpose. This is especially effective for young annual weeds or isolated weeds that have not yet established a strong root system. Just make sure that you are removing all parts of the weed, the roots, the rhizomes, tubers, bulbs, runners, any bit of it, even a one inch fragment can allow weeds to regrow, which is why it is so hard to eradicate perennial weeds by just pulling them. But like I've mentioned, continuous pulling of aggressive perennial weeds will eventually exhaust the root system and then just finally get you some relief. In my experience, you are not going to completely eradicate them, but once you get them under control, you will have much less weeding to do. I can attest to this. With the years that we spent dealing with the field bind weed, I now only have the occasional specimen popping up and when they do, they're easy to spot and I can take care of the problem right away. Number four is to mow them down. So another way to control annual weeds is to cut off their tops before they flower and produce seeds off with their heads. Right. Mow them down. Use a hoe or any other garden tool that's going to take the tops off of them. This is going to reduce their ability to photosynthesize, which means they cannot store any energy in their roots. You can also do this using like a stirrup weeder or a hula hoe to just slice through the soil surface and sever the stems without disturbing the soil too much. So we don't expose new dormant weed seeds to the sunlight and we prevent them from germinating. Now, with perennial weeds, this is another way to help exhaust their energy stores. Especially for perennial weeds that tend to be very large. We pull the Johnson grass by hand when we can, especially in between plants. But in other areas, we're mowing them down as soon as they come up because it's a very large area that we're trying to manage. Eventually we will see fewer new sprouts popping up and then it will be a matter of maintenance efforts, just like with the field bind weed. Now, you know, I didn't mention anything about using herbicides. I prefer not to use any chemical herbicides in my garden. I also don't tend to make any of those sort of natural weed killers. I'm using air bunnies again here that use like household ingredients. You will find all kinds of things for mixing vinegar with salt and with dish soap to make a spray that will kill most annual weeds on contact. But if you're not careful to not spray these on the plants that you want to keep, number one, it's going to damage them too. Number two, we really do not want to be using salt, especially the amount of salt that you would need to use in these homemade sprays and putting them anywhere where we plan to grow anything else, because that amount of salt is detrimental to the soil. Another option to this is to use boiling water just to scald the weeds and their roots if they are, say, in your pathways, or if they are in cracks or crevices in your walkways or in and around your beds. But I just prefer to use manual methods of exclusion and also of removal in order to maintain and control persistent weeds. Look, weeds are a pain, I get it, and they are kind of the bane of any gardener's existence. But I will say mulch is probably the number one way that you can help to prevent them from ever getting a foothold to begin with. Follow by excluding the light, then you can worry about pulling them or digging them up or mowing them down in some way. Really, what you're trying to do is to prevent them from doing what they do in order to reproduce. So make sure you don't allow them to go to seed. Make sure if they're throwing out runners or stolons that you are keeping them from doing that. Make sure if they have rhizomes that you are exhausting that storage organ and keeping it from being able to photosynthesize so it can't put anything else in storage and eventually will die. That'll do it for today. Until next time, my gardening friends. Keep on cultivating that dream garden and we'll talk again soon.

Karin Velez [00:18:50]:

You just finished another episode of the Just Grow Something podcast. For more information about today's topic, go to justgrowsomethingpodcast.com where you can find all the episodes, show notes, articles, courses, newsletter, sign up, and more.

Karin Velez [00:19:03]:

I'd also love for you to head.

Karin Velez [00:19:04]:

To Facebook and join our gardening community in the Justgrowsomething Gardening Friends Facebook group. Until next time, my gardening friends keep learning and keep growing.