Jun 25, 2018

The Solarizing Solution: 4 Steps to Freedom

Would you believe me if I told you that there is a way to kill off pesky weeds and diseases from your garden? Would you believe me if I told you that all you need to do this is some clear plastic sheeting – sealed over your garden for 6 weeks – to keep your soil weed and disease free for 3-4 months! It all sounds too good to be true, but with a bit of elbow grease, you can “Solarize” your garden. The best news is that the summertime is the BEST time to do it.

What is Solarization?

It’s been a commercial agricultural practice for years now, but Solarization is also a great alternative to chemical treatments for weeds, nematodes, and soil-borne diseases. It works well on an industrial scale, but it’s perfectly achievable for your home garden or homestead. You’ll need to invest some effort up front, but it’ll save you hours of backbreaking work in the months to come. All you need is the power of the summer sun and a few basic supplies and you can take on tricky pests that are hard to get out of the garden by other means.

Nematodes and Other Garden Pains

Many of us shudder at the mention of Nematodes! Once these critters make their way into your garden, they are terribly hard to get rid of. These unwelcome parasites burrow into the root channels of your plants. These nutrient highways from the ground to the leaves are taken over by the nematodes, who steal the nutrients for themselves. Without the sustenance they need, you’ll see wilt and decreased fruit production when your plants are affected. If you pull up your dying plant, you’ll see “root knots” in their root system, where the pests have made their home.

If they’re so hard to get rid of, what can you do to protect your garden? The summer is the ideal time to harness the power of the sun to heat up your soil to get rid of persistent pests and weeds. Our hot and intense summer sunshine is perfect to boost temperatures and keep them high, which is exactly what you need to sterilize the soil with solarization.

nematode plant damage

nematode-caused root knots, a tell-tale sign of nematodes

How to Solarize

Getting rid of nasty pests and boosting the health and yield of your garden to come sounds great. We’ve broken down how you can solarize at home this summer. This process works for any patch you want – from raised beds, to garden patches, even up to multiple rows in small farms. You won’t be able to use the land as you sterilize it, but solarizing in the summer sets you up for a great fall growing season.

What you’ll need:

  • Area(s) that you want to treat, mapped out and measured (it’s helpful to also have sq ft calculated)
  • Roll(s) of 3mil plastic, to fit the area you want to treat, plus about a foot for the edges. You can purchase this right at our store, Shell’s Feed & Garden Supply, Inc.
  • Several large stones to secure plastic. Plan to use them in the center and corners of your treatment area
  • Shovel
  • Hoe, twist cultivator, rotary cultivator, and/or hand tiller tool, if you have them
  • A little patience, a helper if you have one, and some sweat equity

assortment of hand-cultivators/tillers

Step 1: Pull Weeds and Cultivate Soil

Give your solarization process a head start by pulling all weeds from the area you are covering. If you have a rototiller (like in the drawing), you can use that to do the weeding and soil loosening for you. If you’re pulling weeds by hand, get as many of the roots as you can, and shake off the soil. Dispose of the weeds away from your garden beds, especially if they have already seeded. Unseeded weeds could be great compost, but seeded weeds are a better fit for a worm bin, if you have one. After pulling weeds, use a shovel, hoe, or cultivator tool to loosen the soil in the top 4-6.” It’s great exercise, but mixing up the soil is important to make sure your solarization process heats up properly.

Step 2: Rake Gently and Shape Ground for Drainage

If you want to add new dirt or compost to fill in the area, right now is the time to do it! As you rake and shape your soil, you will want to set it up for the solarization process. You’ll want to ensure that rain runs off the bed, instead of collecting in puddles. To do this, rake your bed so that it’s a little humped in the middle. Aim for a shape that is nearly flat, but with a slight curve so that gravity will feed the water down towards the edges of the garden bed. Think of it like a roadway, where there is a slight crest at the middle of the road that provides drainage into the gutters or shoulders of the road.

Do not compact the soil when you rake – in other words, don’t step on it! Stand off to the side when working. If you walk on it you’ll undo your hard work loosening the soil in Step 1.

Step 3: Water

It might seem counterintuitive, but watering is a very important step in this process. The right amount of water will boost your solarization process by conducting heat into your garden. Water will pull the heat from the surface further into the ground than dry soil. However, swampy muddy soil will not have the proper effect and may block your ability to kill certain pests and seeds in the soil. Like Goldilocks, it needs to be just right.

The morning after it rains is always a good time.If you have an irrigation system for that area, about an hour after the sprinklers run is a good time. You can hand-water as well, but we recommend a sprinkler for 20-30 minutes at least.

Step 4: Lay Plastic and Secure Properly

Now for the last and most important step: laying and securing the plastic.

Take your 3mil thickness clear plastic and measure out a piece that is about 12 inches bigger than your area (you need extra along the edges to secure the plastic). Stretch your plastic tightly over the area – this is where having a helper is especially beneficial – and place stones on the corners to hold it down. Using the shovel, bury the edges of the plastic completely underground so that wind and rain will not disturb them and pull them up. You want your patch of garden to be safe and secure under the plastic covering for the sterilization to work. Here are some example pictures:

Note: If your edges are sufficiently weighted down, you don’t need the stones in the middle.

If you get a rip or hole in the plastic, a small piece of duct tape should hold it closed enough for the solarization to be effective. However, large holes or animal digging can compromise the process, and might not kill off all the pests and weeds.

Leave the plastic for at least 6 weeks to make the solarization effective. Less time will mean less pest-killing potential. Once you remove the plastic, avoid putting new dirt into the bed, as you might be re-introducing weeds, pests, or disease into your newly-scrubbed bed.

The effects of the “cleansing” usually last up to 3-4 months, which is long enough for a Fall Garden! You can consider the solarization process to be a key prep-steps to get ready for the Florida Fall Gardening season, which is an amazing time to grow all kinds of goodies.

Note: If during your Fall Gardening after you’ve planted your plants you notice weeds popping up right near/under your plants, these are weeds that were in the soil that came from the plant grower. Because if this, I recommend growing your Fall Garden, after Solarization, from seed, just so you can thoroughly enjoy the benefits of being weed and pest free! Also, mowing/trimming can kick weed seeds into your garden beds, so just be aware that this can happen and be cautious when you are mowing and trimming to direct the grass outlet away from your garden!

Hope this was helpful, please let us know if you have any questions!



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