If you have an organic garden, you’re most likely growing tomatoes. Seems like everyone does. This is a good thing, as tomatoes are packed with nutrition, can be used in hundreds of recipes, and are fairly easy to grow. Harvesting that first big juicy tomato is a gold star kind of day.
Growing tomatoes is incredibly rewarding. Except when you have problems with weather, insects, soil, or disease. Then they’re a highly disappointing crop for your garden.
Those of us who’ve been growing tomatoes for decades have learned from our mistakes (which can be many, as in my case). But now I have it down to a science and can share these ten tomato-growing tips with you that serve me well each season. Naturally, one can’t control the weather, which can make a mess of things overnight.
1. If you have the room, start your tomato plants from seeds indoors
Since I’ve been starting my tomatoes from seed every year, I’ve had fewer problems with pests and disease. There simply is too much opportunity for plants to pick up insect pests, viruses, and fungal infections between the greenhouse, the shipper, and the nursery – especially big box store nurseries which typically take terrible care of their plants. Once a plant is stressed by insects, a lack of water, or an infection, the plant may be doomed. At the very least it won’t produce a bumper crop of tomatoes. Growing tomatoes from seed also allows you to grow many amazing heirloom tomatoes, most of which you’ll never find at your local plant nurseries. Learn about starting plants from seed.
2. When you plant your tomato, plant the stem sideways, not vertically
Tomatoes can grow roots anywhere along their stems. Most people plant the tomato vertically, up to its lowest leaves. The tomato will probably do fine this way if weather conditions cooperate all season. But if you have a drought, the plant may not be able to reach enough water, and its roots may not provide a large enough anchor to survive a wind storm or unusually heavy rain. When planting the stem horizontally, the tomato grows a larger root mass which gives it a better chance of surviving droughts and wind.
How to do it: Gently remove all of the bottom-most leaves on the stem, but leave those on the top third of the plant. Dig a narrow trench to a few inches below the surface, but wide enough to accommodate the root ball. Lay the plant in the trench and gently bend the top of the plant so that only the leaves are above the soil – you will bury the root ball and the stem horizontally. You may have to adjust the trench a little since the root ball is wider than the plant and must be a little deeper. This causes the plant to be slightly angled towards the surface. Then cover the stem with the same soil you just removed.
The plant at first will look a little strange buried up to its neck like that, but in a few days the top of the plant will turn towards the sun and start to grow vertically.
3. Site tomato plants where they’ll get direct sunlight all day
Before you plant, make sure your garden bed gets direct sunlight from dawn until late afternoon – it’s okay if they’re in shade from 4 PM on – it may even save them during extreme heat. By direct sunlight, I mean sunlight contacts the leaves – not ambient light. Tomatoes may produce in shadier areas, but not to the extent they will in direct sunlight. Sun also helps to dry the leaves faster after rainfall.
4. Space tomato plants according to their mature size
When I started growing tomatoes from seed, I had more plants than I knew what to do with. So I squeezed an extra few into my raised garden beds each year. At planting time, this was really exciting, knowing I was going to have all of those tomatoes in July.
But it was a big mistake. Over the season, too much foliage was packed in the garden bed, which made for too much dampness after rain. As a result, diseases like late blight took over and ended my tomato season early more than once. If you live in an arid area, packing plants close together may be no problem, but if you’re in an area that receives moderate to heavy rain, this is a bad idea. Always allow at least 12 inches between plants and 14 inches if possible. Use containers for extra plants or give them away to a fellow gardener.
5. Companion plants shade tomato roots and support beneficial insects
For years I’ve planted basil, parsley, dill, marigolds, and other herbs and flowers on the sunny side of my tomatoes. This not only attracts pollinators but also shades the tomato plant roots from scorching sun and suppresses weeds. And if the roots are shaded it cuts down on the need for water and protects the plant from drought stress.
6. Tomatoes need lots of water
Watering tomatoes can be tricky – too much and they stop producing; too little and they stop producing. Hitting the sweet spot is key.
If you’ve planted your tomato as recommended above (horizontally), the roots should spread sufficiently to take up water from a wide area around the plant. This will definitely help. Make sure your plants receive at least one inch of water every week in the absence of rainfall. When you water, only water around the root zone – you want to keep the leaves as dry as possible to avoid fungal infections.
Remember – if you planted the tomato horizontally the root zone is now pretty wide, so soak the soil around each plant sufficiently. And do not skimp – tomatoes do not thrive with “a little drink” every day – this encourages shallow rooting. Soak them deeply once a week, maybe twice if it’s hot or very dry, and that will be sufficient. Mulching the bed with straw or a similar mulch is helpful to limit evaporation and cool the roots. As a bonus, the mulch may also help suppress soil-borne diseases.
7. Tie tomato vines to a stake
A lot of gardeners swear by tomato cages but I’ve never understood this – the foliage is crammed in there and finding the tomatoes at harvest seems difficult. Plus, foliage packed tightly invites disease.
I used tomato cages one year and I never will again. Instead, I use the old-school method of tying tomato vines to wood steaks (not plastic). The best choice is 7-foot cedar stakes. Since your stake will be 12-18″ below ground, you need 5-6 feet above ground to train your vine. Once it reaches the top of the stake, prune the top of the plant off to keep it from spilling over the top. This also allows the plant to focus its energy on fruits and flowers already developing. Any fruit that starts after the plant is this tall probably won’t be ready for harvest before frost anyway.
You also want to control the additional stems that grow from the root of indeterminate (vining) varieties, which can be up to four. Train the main stem up the stake – if you have the room, use smaller stakes to support the additional stems to get the foliage off the ground, or you can prune them out entirely. Your plant will still produce a lot of tomatoes. Indeterminates (shrub varieties) don’t need staking.
8. Prune your tomato plants to prevent disease and increase fruit size
One of the keys to growing tomatoes is pruning indeterminates. In the first few seasons that you’re getting the hang of it, you may think that you’re diminishing the strength of the plant or the harvest in some way, but you aren’t. You’re focusing the energy of the plant on growing larger but fewer fruits and removing foliage that may contribute to disease.
After the tomato plant grows about two feet, start pruning out the foliage closest to the ground so the soil can dry quickly. This discourages fungal diseases on the leaves from soil-borne infections (many varieties of fungi live in the soil and splash onto leaves during watering or rain). Depending on the variety, it may also grow additional stems from the root. If you have the room, you can allow these to grow, but I typically limit these to 1 additional stem and prune out the rest.
As the plant grows you also want to prune tomato suckers, as they pull nutrients from the main stem. Suckers are stems that grow in the “crotch” between the main stem and a lateral shoot. I’ll acknowledge that some gardeners disagree with this and do just fine, suckers and all. You can read more about pruning tomato suckers here.
9. Be vigilant about pests and disease
Even the best gardeners sometimes lose their tomatoes to pests and disease. Much depends on the weather and other local conditions. But after a few seasons, you’ll develop an eye for early signs of disease and insect damage. When you spot yellowing or otherwise distorted leaves, prune them out immediately and trash them – never compost them. Take pictures of the leaves and use resources on tomato pests and diseases to learn the cause (see below). If necessary, take steps to treat organically.
10. Use more compost than fertilizer
Growing tomatoes successfully with organic methods has a lot to do with the condition of your soil. The better it drains, the fewer problems you’ll have with disease. And more organic matter in the soil stores water and helps plants take up nutrients. To get that organic matter you need lots of compost.
A month or two before planting, top dress the entire garden bed with 2″ of compost. For extra points, use a cover crop to protect the garden bed over winter. After your harvest, and when you’ve pulled the plants out for the winter, top dress it again with 2″ of compost. Repeating this each season ensures that there is sufficient nutrition for the plant and plenty of organic material in the soil. Your need for fertilizer will be eliminated or greatly reduced.
Resources to identify tomato diseases:
- Common Diseases of Tomatoes, Mississippi State University Extension
- Diagnosing and Controlling Fungal Diseases of Tomato in the Home Garden, Rutgers University
- Vegetable MD Online, Cornell University
- Tomato Diseases and Disorders, Clemson University Cooperative Extension
- Tomato Diseases, North Carolina State Extension