The tomato is the most popular vegetable grown in the world. (Okay, technically they’re berries, but you don’t usually see chocolate-covered tomatoes in a grocery store.) They are very easy to grow, and come in many delicious varieties, from small cherry tomatoes to giant beefsteaks. They can grow up to ten feet tall, and can fit in as little as one to three square feet of ground space. Tomato plants can be grown in a container if you don’t have access to a garden.
Whatever variety and flavor you decide to grow, the taste, texture and nutritional value of your tomato is determined by the soil condition in your garden. And if you are an organic gardener, you will know that the health of the soil is the basis for everything else.
Condition Your Soil
If you have used synthetic fertilizers in the past, you will likely see your garden producing less and less crops. Chemical fertilizers can be compared to using steroids – they give a short, powerful boost to your plants, but in the long run your soil is depleted of healthy, natural nutrients. Fortunately, it’s easy to kick the garden drug habit. Organic gardening is simply thinking long term, using natural fertilizers to build your soil up. Healthy soil means healthy plants, and healthy plants produce better, taste better, and are better able to fight disease.
To condition your soil, mix in fertilizers such as organic compost and cow manure. If you create your own compost, you have a natural and free source of nutrients, otherwise you can buy packages from garden centers. If purchasing, look for dark, organic humus. If it’s still brown, it’s not ready. Humus is the end product of the natural break-down of organic ingredients, and is the best for your garden. Mixing it into your soil firms up sandy soils and loosens clay.
Once you begin building up organic material into your soil, nature will begin helping over. Earthworms, beneficial bacteria and fungi, microbes and other soil organisms will begin thriving in your soil, boosting the health of your plants. This is the type of soil you will be using to grow organic, nutritious tomatoes. Renew this every year to continue the process.
Planting Your Tomatoes
Whether by seed or from a garden center, plant the starter plants outside when the danger of frost is past and trees in your area are well on their way to full leaves. Tomatoes love full sun, so plant them in the sunniest area of your yard. If you do not have soil in a sunny area, consider planting them in containers and moving them there.
Don’t plant your tomatoes in the same area of soil year after year. They are very hungry and will deplete the soil, and pests will know exactly where to find a tasty meal. Also, use a soil tester to find out the acidity of your soil. Tomatoes grow best in a pH between 5.8 – 7, which is neutral. Lower the pH with peat moss, pine needles and oak leaves. Increase it with wood ash or powdered limestone.
Dig a large planting hole to loosen the soil around the root ball and ease the way for questing roots. Ideally, the hole should be big enough to bury a basketball. Prepare the soil by filling the hole with water the day before. Let the water soak in— your tomato will dig it. Fill the hole part way with compost. Add a fistful of fertilizer such as bonemeal or compost tea. Even a couple of crushed eggshells will help.
Break off all but the top 3 or 4 branches and bury the plant deeply, so the soil covers these former branch sites - they will form roots, giving your tomato an extra solid foundation. Once the tomato is in the ground, soak the surrounding soil, but try to keep your plant’s leaves dry.
The Growing Season
After transplanting, water when the top inch of soil is dry. Do not try to keep the soil moist, rather, make it your goal to not let the soil dry out completely.
When you see tiny fruit on your tomato, cut back on the water and fertilizer. This change tells your tomato that it is time to focus on producing fruit. Water the ground around the plant, but try not to get the leaves wet. Water splashing up from the soil can spread disease.
Throughout the summer, add a handful of compost into the surface soil once a month, but do not over-feed. If the fertilizer is high in nitrogen (the first number on a fertilizer label), it will encourage the plant to grow leaves, when you instead want it to grow large fruit. If the leaf tips begin turning yellow, then gently phase in more fertilizer.
For a well-behaved vine, prune to a single stem, or a Y-shaped vine of a short mother stem and two long main stems. In areas with intense sun, such as the southwest, more leaves are welcome, as a single stem can result in sun-scalded fruit.
Go vertical with your tomatoes! This increases fruit yield and decreases the chance of diseases and pests. This means tying the plant to a large tomato stake. Use garden, cotton or nylon twine. Some gardeners even recommend old pantyhose, which has the advantage of stretching. For the highest yields, plant 18" apart, grow them in single or 'Y' shaped vines, and tie them straight up.
If you are using cages, prune so you get 3 or 4 main stems instead. Pinch off their growing tips once they start spilling out and blocking the light of the tomato the next cage over. When you get a heavy fruit cluster, support the stem with ties to the cage, otherwise the weight of your fruit may damage your vine.
Avoiding Pests and Disease
Frequent visits will help you stay in touch with your tomato’s health. Problems are minor when dealt with as soon as they appear. Tomato hornworms eat leaves and fruit, and leave their calling card: black droppings. Pick the hornworms off and squish them; disgusting, but effective!
Try using homemade pest repellent, especially if you see little white bugs on the underside of the leaves. See the end of this article for a safe, organic recipe.
The tomato fruit can crack from uneven moisture, or have scars and holes in the blossom end from cold weather or too much nitrogen. Ugly tomatoes still taste great, though. Just cut out any bad parts. Blights, late and early, disfigure both leaves and fruit. Wilts can kill tomato plants.
Prevention is the best cure:
- Moisture control is key to disease control
- Water at ground level instead of overhead
- Don’t tie or prune your plants when they are wet
- Don’t plant in the same area two years in a row
If you need to use a pesticide, consider plant extracts, such as chrysanthemums (Pyrethrins) or a naturally occurring pest poison, such as Bacillus Thuringiensis (Bt).
Twist the fruit, don’t pull, or you risk taking the stem with it. Pick tomatoes when they start to soften, have a tomato scent, and most of the fruit has achieved its final color. Of course, there are lots of good uses for unripe (or green) tomatoes as well! A green tomato will achieve full color and flavor when left on a sunny windowsill or railing.
As the season wanes, get every last bit of tomato goodness! With a month left of warm weather, cut off all growing vine ends and all small and undeveloped fruit. Cut back on water and fertilizer so the plant focuses on ripening its existing fruit.
Homemade Pest Repellent
This spray will help against whitefly, aphids, beetles, grasshoppers, slugs, and scale. It also can help deter rabbits and raccoons.
- 6 cloves garlic
- 1/2 onion
- 1 tablespoon cayenne pepper or 3-4 very hot peppers or 1 tablespoon of hot pepper liquid, such as Tabasco
- 1 tablespoon phosphate-free, biodegradable dishwashing liquid
- 1 quart water
Put the first four ingredients in the blender along with a cup or two of water. Blend until smooth. Pour the liquid into a large jar and add the rest of the water. Let it steep for about 24 hours, and then strain out the solids. Pour the liquid into a spray bottle and spray your plants, making sure to get the underside of the leaves, too. The spray keeps in the refrigerator for up to two weeks.
Written by Chris Molnar and Ena Clewes. Ena is a professional horticulturalist who has written a book on organic gardening . Visit Goorganicgardening.com for more gardening and vegetable-growing tips.