Tomatoes are a vegetable gardener’s most prized crop.
Tomatoes make us work hard to reap the rewards of harvest.
Of all the vegetables that we grow, tomatoes seem to require the most nursing and care. Anyone that’s grown them, can speak from experience on their unpredictability and the attention they require to ensure proper watering and protection from disease. Every year is different and depending on the weather may either completely wipe out a crop with disease or produce the most memorable bumper crop ever.
Through years of tomato growing experience and extensive research, I’ve come up with a list of 10 steps for healthier tomato plants.
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Every winter, gardeners dream about growing tomatoes. They spend all winter combing through seed catalogues, looking for a tomato variety they haven’t grown before. From paste tomatoes, to cherry, beefsteak and salad types, there are so many to choose from. The list may further be divided into green, red, brown, yellow or striped. Tomatoes receive a prime growing location in every tomato lovers garden.
In all my years of growing tomatoes, every year has been a completely different experience. However, there are specific steps which may be taken, to give tomato plants the best conditions for growth.
10 Steps to Healthier Tomato Plants:
- Plant your tomatoes deeply: If you look closely at a tomato stem, you will see that it is covered in very small hairs. All of those little hairs can be potential roots. So, the deeper you plant your tomatoes, the more roots it will develop along the stem and the stronger the root system will become. Unlike other crops, tomatoes benefit from being planted deeply. The strength that they develop from deep planting, will allow them to withstand windy conditions, heavy rains and tomato pests, since their extensive root system will act as an anchor in the soil, therefore creating a healthier plant.
I recommend planting your tomatoes as deeply as their first set of true leaves. If they have become quite leggy prior to planting, either due to lack of light or starting them very early indoors, not to worry. Either plant them deeper and roots will develop along the stem, or dig a small trench and lay your tomato plants on their side, with only the top of the plant turned up above the soil. Either method will produce strong tomato plants, that are firmly anchored into the soil.
- Don’t let the foliage touch the soil: Several years ago, I experienced the most severe case of Late Blight, I could have ever imagined. My tomato plants were planted too closely together, directly on the soil and weren’t properly staked. They overgrew the walkways and I could barely get through them. Then the rains began and wouldn’t stop until the end of summer.
Those tomato plants became a slimy black mess. The tomatoes got covered in black spots, that quickly turned to mould. The plant leaves and stems developed black circular spots, surrounded by white fuzzy spores. I managed to harvest a few tomatoes, but most plants didn’t produce even one edible ripe tomato.
What I learned from that experience are the preventative measures that can be taken to lessen the effects of late blight. The primary lesson learned is the importance of keeping all tomato foliage off the soil. The soil harbours harmful insects and bacteria. By keeping all leaves off the soil, you are preventing the infestation of foreign organisms. Had I removed the lower leaves throughout the plant’s growth, I would have created a nice airflow beneath the plants.
- Water at soil level, being careful not to splash water on the leaves: When watering your tomato plants, it is best to be vigilant and avoid watering your plants from above. Tomatoes do not benefit from having wet foliage for a couple of reasons. 1) Wet leaves exposed to sun, may cause leaf scorch, and 2) wet tomato leaves expose the plant to fungus and disease.
Be careful when watering your tomato plants. Be sure to direct your watering wands and cans directly at the soil line and avoid watering the foliage as much as possible.
- Stake according to plant variety – determinate/indeterminate: Before planting your tomatoes, be sure to do a little research and find out if the varieties you’re planting are determinate or indeterminate.
Determinate tomatoes are those that grow to a specific height and produce a finite number of tomatoes. Indeterminate tomatoes have a vining growth habit and will continue to grow as long as a trellis or support is provided. They produce an infinite number of tomatoes.
For determinate tomato varieties, a tomato cage is often plenty to support their growth. However, indeterminate tomatoes require a stronger support to hold up their weight and tomato production. Be sure you know the growth habit of the tomatoes you’re planting. Then stake your tomato plants at the time of planting or shortly thereafter. If you wait too long, your tomato plants will become overgrown and impossible to stake.
Based on the variety, a different staking method may be required.
- Prune suckers of indeterminate plants only: Indeterminate tomato plants produce an infinite number of tomatoes and as each stem develops, a sucker stem grows from the joint where the stem and leaf are connected. If those suckers are left in place, the tomato plant will spread out sideways and overtake all neighbouring plants. In addition, energy needed to ripen fully developed tomatoes will be redirected to producing sucker stems and more tomatoes along those suckers. Instead, remove all suckers on indeterminate plants as they appear and allow the plant to focus it’s energy into developing tomatoes along the main stem.
Don’t prune the suckers of determinate plants! Determinate plants produce a finite number of tomatoes. If sucker stems are removed, you will be removing a major portion of your total harvest.
It is best to be informed about the tomato varieties that you’re growing and their growth habit, before deciding to prune off sucker stems or not.
- Water consistently and deeply: Tomato plants and their developing fruit are much healthier when consistently watered. Irregular watering (where the plant is allowed to dry out, then watered again) and droughty conditions, lead to a physiological condition in tomatoes called blossom-end rot. Blossom-end rot develops on the blossom end of the fruit, as a brown leathery patch, which starts off the size of a dime and eventually expands to cover the entire base of the fruit, becoming rotten and mouldy.
Blossom-end rot is the result of calcium deficiency in the plant. When the plant is left to dry out, it leaves the plant unable to uptake calcium from the soil, needed for the formation of fruit. As a result, the cell walls break down, leading to blossom-end rot. If the plant continues to receive irregular watering, the condition will worsen leading to a drastic reduction in tomato yield.
To remedy this condition, it is best to water your tomato plants every couple of days and for longer periods of time. During periods of drought, more frequent watering may be necessary. If your tomatoes are growing in containers, daily watering will be necessary and possibly more than once a day.
To conserve moisture in the soil, consider mulching it with straw, shredded leaves or plastic.
For more information on watering, please see my post “10 Ways to Properly Water Your Garden“.
- Plant your tomato plants in a full sun location: Most vegetables, especially heat loving ones like tomatoes, require at least 6 to 8+ hours of full sun daily, in order to develop properly and produce fruit.
In northern climates, where summers may be cooler and wetter, more hours of full sun are required.
In the south, where temperatures climb during the height of summer, some sun protection may be required in the afternoon, to protect plants from burning and losing pollen on extreme heat days.
The best way to gauge this is by the temperature. If your temperatures climb above 32 Celsius (90 Fahrenheit), and stay at that temperature for at least a week, some sun protection may be required, in order to not lose developing flowers. If they stay below that temperature or only reach it for a day or two, full sun is best.
- Leave enough room between plants: Tomato plants require at least 2 to 3 feet of distance from each other when planting. However, this distance is based on the size of the plant and how it is grown.
In a greenhouse, for example, tomatoes are spaced close together and trellised with a tough string or rope from the ceiling of the greenhouse. All side shoots are removed, leaving only the main stem. Tomato plants are indeterminate and will grow to the height of the greenhouse. In this environment, tomato plants may be spaced 1 foot apart or closer.
In a traditional vegetable garden setting, two to three feet is best, in order to provide air circulation for the plants and to prevent leaf overlap from neighbouring plants.
The year that I experienced the worst case of late blight, my tomatoes were not properly staked, and were planted too closely together. The plants grew into one another and their leaves overlapped. I learned that proper spacing is necessary and the more room you have between plants, the less chances you have of disease.
- Feed the soil when planting: Prior to planting out your tomato plants, prepare the soil. Clear the soil of any left over plants from the previous year, including dry debris. Remove all weeds, grass roots, etc. Then top the soil with a 2-inch layer of compost, composted manure, leaf mulch, or whichever you prefer. I prefer to do this step and leave it for a few days to a week, to settle in.
Then at planting time, I add a spoon of volcanic rock dust and bone meal, to each planting hole. You can add worm castings if you’d like, as well. I only use organic materials, no chemical fertilizers. Then I plant my tomatoes. On the surface of the soil, I add another spoon of volcanic rock dust and the plants are good to go.
I find this nutrient boost gives the tomatoes a healthy head start. I don’t add any fertilizer that is high in nitrogen, and lower in the other nutrients, because I want the plants to focus their energy on not only producing leafy growth, but strong roots and flowers, as well.
If you’re uncertain of the quality of your soil, consider doing a soil test. That way you’ll know for sure if and what your soil is lacking.
- Rotate your tomato crops every year and don’t replant tomatoes in the same spot for at least 3 years: Do you rotate your tomato plants every year? If you don’t, you might have noticed less productive tomato plants and a reduced harvest year after year.
Tomato plants are heavy feeders, that starve the soil of its nutrients after completing a growth cycle. In addition, tomato plants are prone to a multitude of diseases. If tomato are replanted into soil that was previously occupied with tomato plants, that soil will be lacking in the nutrients required to sustain another tomato growing cycle. In addition, tomato pathogens can remain in the soil after the first year. Any diseases left over in the soil, may easily infect newly planted tomato plants.
As a result, it is best to plant your tomato plants on a 3-year rotation. Choose a spot in the garden for year #1 tomato plants. Then rotate your tomato plants to a different location in the garden for year #2. In year #3, choose another site. By year #4, the original planting site from year #1 tomatoes will be replenished of its nutrients by growing out less nitrogen-heavy crops and will be ready to support newly planted tomato plants. In addition, any tomato-related pests and diseases will be free from the soil.
This recommendation applies to other members of the Nightshade (Solanaceae) family as well, like peppers, eggplants and potatoes.
Perhaps you already follow most of the above 10 steps or maybe you only practice a few of them? Maybe these steps have shown you an overlooked approach?
A healthy tomato plant has the strength to protect itself from predator attacks and unstable weather patterns. If you give your tomato plants the right head start, they will have a greater likelihood of growing into healthy tomato plants. If a tomato plant is healthy, it can focus it’s energy into producing tasty fruit.
For advanced tomato growing techniques, like steps for ripening unripe green tomatoes, keeping your plants disease free at the end of the season and what to do once tomato season is over, sign up to receive my free PDF for an additional “8 Steps to Healthier Tomato Plants” above.
I’d love to hear about your tomato growing experience and any tried and true techniques that you use, when planting tomatoes. Please feel free to share your experience in the comments section below.