Raising Your Tomato for Success
Some of the most common questions that we receive in the Extension office involve growing tomatoes. Often these questions revolve around problems that could have been prevented. Tomatoes, like most plants, grow best when supplied with adequate sunlight, water, space, and nutrients. When we deprive plants of these essential requirements, they become more susceptible to stress and disease. In Pamlico County, adequate drainage is one of the most important considerations to help limit stress and prevent disease. Excessive soil moisture deprives roots of oxygen that can lead to root rot, infection from disease, and an overall reduction in plant growth.
Soil drainage can be improved by bedding soil into raised rows or beds, or creating garden structures that add depth to soil. Trying to change the soil structure of poorly drained native soil through soil amendments alone (adding compost, soil conditioners, manure, etc.) is usually not sufficient. This is especially true if your garden in located in an area that is prone to flooding or where ground water is near the surface. In these situations, the depth of freely drained soil is more important.
Raised garden structures that add 6-8 inches of soil depth should be sufficient for most garden locations. You can create these structures from treated lumber, concrete blocks, or composite materials. These structures should be filled with compost or potting soil to allow for maximum drainage and disease prevention. You can also use bulk soil to fill these structures, but this may introduce weeds and diseases with no guarantee that this soil will provide adequate drainage. If you do use bulk soil, the addition of compost is highly recommended.
If your raised garden structure will sit directly on the ground, you should take steps to control weeds in that area. A non-selective herbicide like Roundup (active ingredient – Glyphosate) will work well, but cultivation is also effective. You may need to cultivate several times before building your structure to allow multiple flushes of weed seed to germinate that will result from cultivation. This will help to reduce the overall amount of weed seed under your structure and reduce the potential growth of perennial weeds.
Once your structure has been built, do not forget that tomatoes need an adequate supply of nutrients to grow well. Raised beds filled with compost should have a neutral pH, but will need additional inputs of fertilizer. If potting soil was used, these products may contain a pre-charge of fertilizer that will help plants early in the growing season, but additional fertilizer will be needed as plants mature. Tomatoes will need additional nitrogen fertilizer about 3-4 weeks after transplanting, with another application when fruit begins to form. If you use bulk soil to fill these structures, then conduct a soil test to determine if the pH and nutrient levels are sufficient. Do not assume that bulk soil or products labeled as top soil have any additional nutrient qualities. If you are reusing soil from a previous growing season, then additional nitrogen fertilizer will be required during the growing season. You should assume that the majority of nitrogen fertilizer applied the previous season has either been used by previous crops or leached from the bed.
Lastly, raised beds will dry out faster than native garden soils. Pay attention to your plants and water before signs of wilting occur. Drip irrigation is a more efficient method of supplying water to your plants and will help reduce the spread of disease from splashing of water and soil. Drip irrigation can also help provide a more constant supply of water that will help regulate soil temperature. These factors will help to reduce stress related issues like blossom end rot.
If you would like to learn more about growing tomatoes or how to create raised garden structures, please contact Daniel Simpson at 252-745-4121 or firstname.lastname@example.org. You may wish to review the “Soil, Plots and Planters” chapter from the NC State Extension Community Food Gardening Handbook. An additional resource for information can also be found in the Extension Gardener Handbook in the chapter titled “Plants Grown in Containers”.