Solarizing and Mulching the Garden

Since we’ve had high temperatures, high humidity, and frequent rain all summer, I was expecting to find the school garden full of weeds. When I checked it this week, I was surprised and pleased with the condition of the garden. There were plenty of weeds around the garden but not in the garden itself. Our preparation for summer in Florida was successful.

In early June at the end of the school year, we solarized the upper level of the garden. The purpose of solarizing is to trap the sun’s rays below a layer of plastic to heat the soil enough to kill the pests, especially the nematodes. To prepare to solarize we pulled out the last of the tomatoes, peppers, and the  few weeds that were growing. We raked all of the mulch from between the rows and added it to the lower level butterfly garden. Next we thoroughly wet the soil in the upper level before covering it with clear plastic. The edges of the plastic were anchored in the soil and weighted with a few bricks. The plastic remained intact all summer and is still anchored on the edges, so there are no weeds in the upper level of the garden.

Last year we didn’t seal the plastic as well around the edge and used a thinner plastic, so we had gaps around the edge and in the middle where the plastic had failed. It was full of weeds at the end of the summer last year. Since our garden soil is still covered with the layer of  plastic this summer, it doesn’t just mean the weeds couldn’t grow, it also means that the solarization process will have killed more of the nematodes than last year. That is good news and should result in healthier plants during the coming year.

The butterfly plants in the lower level has mulch between the plants. The purpose of the mulch is to help hold the moisture in the soil and to prevent the growth of weeds. At the end of this summer our lower level has healthy looking butterfly plants that have thrived in the summer rain and sunshine. There are a few weeds, but the mulch has done what it should to prevent most of the weeds from growing. It will just take a few minutes to get rid of the weeds to have the butterfly garden in good shape again.

Solarization in upper level

Solarization in upper level

Butterfly garden with mulch in lower level

Butterfly garden with mulch in lower level

Solarizing the School Garden

Early last June, the school garden was neglected for a few weeks while students completed the school year. It was soon choked with weeds. We knew we couldn’t leave it all summer without taking care of the problem, so we decided to solarize the garden. I bought large sheets of clear plastic from Home Depot and packages of the anchors that are normally used to hold down black weed mat fabric. Then I asked for help. Mr. Maciejewski, one of the parents in the school, has a landscape maintenance service. He removed the weeds, then covered the soil with the plastic and anchored the edges. Mrs. Bujak-Dominiak and I would like to thank him for his efforts on our behalf.

It is best to solarize for at least 6 weeks. Our garden was covered from mid-June to early September, so we had a few extra weeks of solarization benefits. The photo shows the garden in late August. Some of the summer storms had pulled the edges loose in spots, and a few weeds has grown in the space under the plastic in those areas, but most of the garden was clear of weeds.

Solarizing is based on the green house effect. As sunlight passes through the clear plastic, the heat from the sun is trapped under the plastic. If the soil is moist before it is covered by the clear plastic, the warmed water vapor helps to hold in the heat and makes the process more efficient. The heat prevents seeds from germinating and kills off harmful organisms such as nematodes and soil insects. As you can see from the photo, very few weeds grew during our long-hot Florida summer, so hopefully the nematodes and harmful insects are under control too.

Soil Solarization Success

We realized at the end of the last school year that the soil in the garden needed improvement. Our summer attempt to solarize the soil seems to have helped. Although a few weeds grew around the plastic, and some grew where the plastic has ripped, most of the weeds under the plastic were dead by the beginning of August. We can see that the addition of the compost and the solarization seem to have improved the quality of the soil, so we are hopeful for this year’s crop of vegetables.
solarizing

Solarizing the Garden Soil

Last June after the close of the school year, we decided to solarize the garden for the summer. We removed weeds, then borrowed a rototiller to loosen the soil. Next we added several bags of compost from a nearby farm. The final steps were to wet the soil, and then to cover the soil with a clear plastic. The purpose of the plastic was to solarize the soil:

Soil solarization is a practice used to manage weeds, nematodes, diseases, and insects in soil. The soil surface is covered with clear plastic, which allows sunlight to pass through and heat up the soil to temperatures that are lethal to many of these pests. If effective, solarization can reduce population levels of these pests for 3-4 months, sometimes longer.(Read Introduction to solarization on ifas website)

We weighted the edges of the clear plastic with soil, boards and cement blocks to seal the edges as best as possible to retain the heat under the plastic. In the first photo, the lower layer is solarized with the plastic, but the upper layer of the garden is still a mass of weeds. The second photo shows both layers of the garden covered with the plastic. Then we left it to the Florida summer heat to do the work.

solarizing

solarizing