Tips on Growing Tomatoes
“Ain’t nothing better than a home-grown, one-slicer tomato sandwich,” commented the exasperated gardener visiting Cooperative Extension’s Plant Clinic last week, “but all my plants either die before I get even one tomato or stop producing when it gets hot.” Even seasoned gardeners often share this fellow’s frustration in the quest for a tasty tomato in the challenging conditions of southeastern North Carolina. Diseases that attack the roots and the leaves, nematodes, poor soils and, yes, even the heat, conspire to limit your success with this fruit once known as love apple.
Tomatoes grow best in rich, well-drained soil with plenty of sun. Unfortunately, we have both well-drained and poorly-drained soils, but few that would be considered “rich.” So, that means you have some work to do.
Test your soil
Use the soil testing service available through Cooperative Extension (at the Arboretum in Wilmington) to find out about the basic fertility of your garden spot including the often discussed pH. Except during the lab’s busy winter months, the service is still free.
Soil pH is important because it affects how your plants take up the nutrients they need to grow and thrive. Living along the coast means pH’s can range from very acidic (3.5) to fairly alkaline (8.0). Anything below 6.0 or above 7.0 is going to limit your tomato success.
The soil test will recommend lime to raise the pH if it’s too low, sulfur to lower it if it’s too high and suggest fertilizers and amendments to keep those tomatoes happy.
Add compost and more compost
You’re not finished playing with the soil just yet. Because it’s hot and it rains a lot, we always need to add more organic matter. Each time you prepare your garden area for planting, add 4 to 6 inches of compost and mix it thoroughly into the soil with a rototiller or spade to a 6 to 8 inch depth.
Follow this plan for several years and you will have a high organic matter soil that can almost be worked with your fingers, that is if you like to be intimately involved with your soil.
While compost helps sandy soils hold on to water and nutrients and improves the drainage and aeration of clay soils, it won’t provide enough of the good stuff to grow that perfect tomato. Organic or standard slow-release fertilizers are still necessary.
That juicy tomato is more than 90% water, so adding the right amount of water is important. And, it’s very important that the soil stay consistently moist – not cycling from very wet to very dry – to minimize the stress on the plants. This type of stress will lead to problems like blossom-end rot and leaf roll.
Since tomatoes are susceptible to lots of fungal leaf diseases, the best way to water is with low-volume or “drip” irrigation. The simplest system is just a soaker hose attached to a spigot. More complex systems with drip tubing and timers can take some of the labor out of watering correctly.
Use large containers
If nematodes and bacterial wilt make growing tomatoes in your regular garden spot impossible, consider using large containers filled with potting soil. These pine bark-based “soils” don’t actually contain soil, but they are exactly what you need in a container. The equivalent of a 5 gallon nursery container is the bare minimum to grow even “patio” or “bush” tomato varieties. Standard varieties will do better in something like a half whiskey barrel. Cherry tomatoes are easier to grow, very productive and are great choices for beginning gardeners.
Remember where you live
While tomatoes are tropical plants most varieties don’t set fruit well when the temperatures climb into the mid-90s. That’s why it is important to get started as early as possible after the danger of frost has passed in the spring (usually April 10 or so). Because of the disease pressure and the heat, many seasoned gardeners plant a fall crop in late July/early August.
For more information on growing tomatoes in the Cape Fear region, visit ces.ncsu.edu where you can submit questions via the ‘Ask an Expert’ link, or contact your local Cooperative Extension center. If you live in Pender County, call 910-259-1238; in New Hanover County, call 910-798-7660; in Brunswick County call 910-253-2610.
Susan Brown is the consumer horticulture extension agent with the North Carolina Cooperative Extension in New Hanover County. Contact her at firstname.lastname@example.org 910-798-7476