Will using leaf or grass mulch around the base of the tomato plant allow for the formation of substances that fight some of the various tomato afflictions, leading to healthier plants?
No. As a physical barrier that prevents spores from potentially diseased soil from splashing up onto the lower foliage of the plants, mulch is a very effective tool that contributes to a healthy garden. Mulching also helps to slow down water loss from the soil on very hot days, which can help reduce the formation of blossom end rot.
As mulch breaks down it forms humus, which acts as a natural fertilizer for the plant. But there is no direct evidence that mulch itself leads to the formation or existence of actual disease fighting or disease-blocking compounds.
Will removing all of the foliage from the plant increase the production, flavor, or quality of the tomatoes?
No. In fact, this is detrimental. The removal of all foliage from tomato plants is an invitation to numerous issues and will significantly reduce the quality of whatever fruits manage to grow to maturity. With no foliage to shield the tomatoes from the searing heat of summer’s direct sun, sunscald would have a significant impact on most, if not all, of the tomatoes, ruining the quality. Tomato flavors develop because of photosynthesis going on in the leaves. One of the reasons that indeterminate tomato varieties are generally more intensely flavored than determinate varieties is the vastly increased leaf area, which allows far more chemistry to go on in the plants and results in increased flavor.
This is thought to be the reasoning for the generally superior flavor of indeterminate tomato varieties when compared to determinate types.
Will allowing my tomatoes to sprawl, uncaged and unstaked, result in greater yields?
In theory, yes, but many factors will negate the advantages. Sprawling tomatoes are certainly easier to manage, and it makes sense that just letting them go will allow them to produce enormously. There are many caveats, however.
Most soils contain various bacterial, viral, or fungal agents that can harm the tomato plant and fruit in various ways, so yield is easily compromised by disease, if and when it hits. A good layer of a barrier substance, such as straw, leaf mulch, or non-treated grass clippings, is necessary to keep the soil off the tomato foliage and fruit. Even still, mice, voles, and slugs can do great damage to the tomatoes. A tomato cage, allowing vertical, cleaner growth, achieves the same sort of yield with less potential loss from disease. Sprawling plants are also a potential logistical problem in terms of getting in to harvest the tomatoes without stepping on and injuring the plant. Varieties can also get easily confused, which is detrimental to accurate seed saving. Indeterminate tomato vines can easily reach 10 feet or more in a long growing season, and all of those side shoots (a.k.a. suckers) will reach nearly as long. This explains both the incredible yield potential and the tangle of tomato plant that will likely result.
Do those Topsy Turvy containers really work?
This novelty works reasonably well, but only for small-fruited tomatoes, with frequent watering. The Topsy Turvy is a name brand of a widely advertised hanging planter with a simple premise — the plants are grown upside down, with the seedling emerging from the bottom, roots upward, watered from the top, and hung from a secure hook. This can be considered a space-saving and unique way to grow plants, and it does work.
Strawberries, which produce numerous runners, may do quite well in such a container. Training flowers such as some petunia varieties would be lovely in one. But it is very limited in its use for eggplant because of the upright nature of the growth and vigor of the plant, and it is essentially useless for the fragile-stemmed sweet peppers, though it actually works to some degree for tomatoes, with two significant caveats: A Topsy Turvy device doesn’t hold much soil, so it is limited to one tomato plant for any hope of a decent yield. And because larger tomatoes become heavy as they ripen, a single cherry tomato plant is probably the best use. I planted a single Sun Gold plant in a Topsy Turvy a few years ago and hung it off my deck. As long as I kept it well watered, it thrived, and it hung 8 feet down to the ground, producing a decent crop of tomatoes along the way. Our dogs, in particular, thought it was a splendid idea, especially when tomatoes started to appear at ground level.
Will leaving my grow lights on for 24 hours a day result in healthier tomato transplants?
No. In fact, this practice can be detrimental. “More should be better” is a common supposition. If tomato seedlings benefit from grow lights, then the longer they are on, the happier the seedlings? Well, no. Keep in mind that plants in nature receive a break in the action between sunset and sunrise. Research indicates that the optimum amount of time for tomato seedlings to be under light is 14 hours. No additional benefits are seen between 14 and 20 hours, and possible detrimental effects are seen beyond that (the theory is that a buildup of excess starch and sugars in the foliage promoted by the nonstop light leads to foliage damage).
I turn my grow lights on when I wake up and turn them off when I go to bed, which provides light between 8 a.m. and 10 p.m.; this has worked fine for me. It isn’t necessary to be absolutely specific about the start and end times, so you can fit this to your own particular morning and evening activities. A timer can be very helpful if your schedule is not predictable.
Is transplanting my tomatoes really necessary?
Transplanting is strongly recommended. Transplanting seems to be the norm for the gardeners who start their own tomato seeds, though it is true that, in some climates and for early varieties in particular, direct seeding can work. Often, we find in our garden volunteer plants from the previous season’s dropped tomatoes that emerge once the soil warms and, if we leave them be, turn into fruiting plants. This then raises questions of whether one needs to transplant.
For most of us, transplanting is a necessity because volunteer- or direct-seeded seedlings wouldn’t nearly match the yields of those plants that get their start indoors. In addition, transplanting allows for very vigorous and healthy seedlings, due to root development along the part of the stem that is buried during the transplanting step.
Will my garden be more successful if I plant by the phases of the moon?
Evidence of success are anecdotal, and those who abide by it are passionate. I’ve not tried it myself. Planting governed by the phases of the moon seems to stem from a long-held belief that the moon controls moisture, a principle dating back to Pliny the Elder in the first century C.E. How this theory extrapolates to when we do specific tasks today depends on the beliefs of the individual gardener. The guidelines indicate that the various phases of the moon will be beneficial to different gardening tasks, whether it be seed sowing, planting, or weeding. As always with suggestions that seem to be more legend or myth-based than science based, these provide great opportunities for small projects so that you can explore for yourself which ones do or don’t work for you.
If I save seeds from the first tomatoes that ripen on a particular plant, and I do this for several seasons, will I end up with a tomato that is earlier than the one I started with?
No, since the genetic material in all seeds from all tomatoes on an uncrossed, open-pollinated plant will be the same.
If I save seeds from tomatoes with blossom end rot (BER), will all of the tomato plants from the saved seeds produce tomatoes with that affliction?
No. If a tomato variety is open pollinated, all of the genetic material in each seed in each fruit on a plant is the same. A physiological issue like BER is a result of the conditions experienced during the formation or ripening of the fruit, not of anything genetically distinct about the particular affected tomato, so seed saved from a fruit with BER should be fine. The only exception would be if every single fruit on the plant, and other plants grown from the source seed, suffers from BER; then it is possible that something genetic about the variety is making it prone to developing BER.
Should I remove all suckers from a tomato plant? I’ve heard that they sap energy from the plant.
No, they don’t sap energy. In many cases, leaving some or all can be beneficial. The short answer is that suckers are simply additional growing stems and do not sap energy from the plant. Indeed, there are more reasons to keep them than to prune them.
Will shading my tomatoes to reduce the temperature or using calcium spray on the blossoms prevent blossom drop and increase the chances of a good crop?
These practices have limited effectiveness at best. Each particular tomato variety has a temperature and humidity range that facilitates pollination of the flowers and therefore fruit set. Tomatoes from cherry to medium size seem to be far less fussy and yield more reliably over a wide range of conditions. The large, irregularly shaped beefsteak tomatoes can be fussier, though it is variety specific. Tomato flowers should, in theory, pollinate as they open, from the brushing of the pollen-releasing anthers against the receptive tip of the pistil.
Though it is impossible to control the humidity experienced by a tomato blossom growing outdoors, screening on a very hot day could provide a microclimate sufficient to increase the probability of pollination. To the tomato grower who is salivating at the thought of the crop to come, any simple efforts such as these are worth a chance.
The various hormone and calcium sprays that are applied directly to the blossoms are another story entirely. They are intended for use primarily to promote pollination and fruit set in cooler climates, and their effectiveness in the more problematic hot, humid conditions is likely very low. And even in those cases where fruit set succeeds, the resulting tomatoes tend to be seedless (parthenocarpy), resulting in unpleasantly mealy, even bland fruit that don’t approach the quality of those that pollinate naturally.
Will getting water on the tomato plant foliage lead to disease or damage from the sun’s hot rays on the beads of water?
Damage from the sun is unlikely, but promotion of disease is possible, especially if soil gets splashed on lower foliage. Rain in cool weather can also lead to late blight, if the disease agent is present. Many tomato gardeners do everything they can to prevent wet tomato foliage, but consider what happens to the plant in a heavy rainstorm. It isn’t so much about wet foliage as it is about what may be splashing on the plant that could cause harm. Since many tomato diseases are embedded in garden soil, the most important thing is to prevent soil from splashing up onto the lower foliage by mulching well around the base of the plant. Watering large tomato plants from above is potentially wasteful, as the water cascades off the foliage but, especially if the plant is large, may not provide the deep watering that the plants require. I’ve experienced no issues at all with watering flats of tomato seedlings from above using a gentle spray. But once a plant is seated in its final location, be it pot or garden, it is far more effective to water around the base of the plant to allow for a good soaking of the root zone.
Is it true that the tomatoes on my plant won’t ripen if they’re hidden by the leaves?
No. Tomatoes ripen when they are good and ready, informed by the particular genetics of a given variety. Weather will certainly play a role, but the location of the tomato on the plant doesn’t impact its ripening time at all. In fact, exposed green tomatoes that become roasted by direct sun in the middle of the summer are prone to sunscald. The main problems with deeply hidden tomatoes are the propensity to actually miss them when they are ripe and the opportunity for increased pest attacks because they are more difficult to monitor.
Do I need to vibrate my tomato blossoms or shake the plants each day to get good pollination?
This isn’t necessary, but it could help if the plants are grown to maturity in greenhouses.
The principle behind shaking or vibrating tomato blossoms is that the flowers may need a bit of help to ensure that the pollen from the anther is captured by the tip of the pistil to ensure fruit formation. This is a common practice with greenhouse tomato growers, since there are no natural breezes to move the flowers. It shouldn’t be necessary to vibrate tomato plants grown outdoors.
To test the effectiveness of this practice, it would be interesting to have the same tomato variety side by side, and to vibrate each flower daily (or shake the entire plant — gently, of course) on one plant and totally ignore the other plant. Be sure to collect information on numbers of tomatoes set and total fruit weight.
If you do this, I’d love to know how the experiment turns out.
Should I pinch all blossoms from my transplants, so that the energy goes into the plant, not the first tomatoes?
No. The supposition of this garden myth is that if you have transplants that possess buds or open flowers, or even small set fruit, all of these must be removed when the transplant is set into its final location so that it puts its effort into establishing the plant, not dealing with maintenance of the flowers or tiny fruit. My personal experience is that the plant knows best, and I’ve often gotten some nice early tomatoes (far in advance of posted maturity dates) by leaving any flowers or fruit as I settle the transplant into its resting place. I’ve observed no delay or setbacks with the establishment of the plant; grown side by side, there is no difference in the health or size, over time, of plants with or without flowers and fruit when planted. In my opinion, all you are doing by plucking off those first flowers and fruit is delaying gratification. But, as in the case of the myths that are easily tested in the garden, it is better to “do the experiment” and find out for yourself.
Are tomato diseases passed along on seeds?
Sometimes. Unfortunately for tomato seed savers, a number of serious tomato diseases can indeed be carried on saved seed. The three general types of tomato diseases, caused by viral, bacterial, or fungal agents, are covered in detail in our disease section. Even though fungal pathogens are the greatest in number, they tend to be more of a plant surface issue and, though they can be harbored on seed coats, are far less of an issue.
Bacteria and viruses are better able to navigate the vascular system of the plant and wind up in the seed embryo, and hence the final seeds. Simple seed treatments can be used to minimize the pass-along disease potential from infected seeds. Of course, the best prevention is to ensure seed is saved from healthy plants only.
If I save seeds from hybrid tomatoes, will they germinate?
Yes. Any properly saved tomato seed will germinate, whether saved from open-pollinated or hybrid varieties. So it is not if you get a tomato plant; it becomes all about what you get.
The F2 generation, which is what you are working with if you plant such seeds, will segregate into plants that genetically express the parents of the hybrid, depending on which characteristics are dominant or recessive. In summary, all bets are off when you grow tomato plants from seeds saved from hybrids. You may like what you find . . . and you may not!
Do I need to plant at least two of each type of tomato so that they cross pollinate and produce tomatoes?
No. I am asked this question often during seedling sales by gardeners with limited space.
They want to try out as many varieties as possible but think that two of each is needed to get a decent crop. Fortunately for the intrepid tomato explorer, tomato flowers are “perfect,” meaning that they effectively pollinate themselves upon opening. If you have room for 12 tomato plants in your garden, and you love variety, select 12 different tomato varieties and enjoy the experience of discovery as you learn about each of them.
Is it true that pink or yellow varieties are less acidic than red varieties?
No. According to a study carried out by the USDA in 1977, just about all tomatoes are similarly acidic.
Relative acidity is measured on a pH scale of 0 to 14, with 0 being extremely acidic and 14 being extremely alkaline. Acidity and sweetness are not opposites, however. In fact, honey (with a pH of around 3.8) is actually more acidic than tomatoes (which have a pH range of 4–4.6). Some tomatoes taste sweeter than others simply because their sugar content is higher, which masks the acidity.
When considering which tomato varieties to can, feel free to choose anything that is in good edible ripe condition. Acidity does drop off a bit with age, so very ripe tomatoes, which often taste unpleasantly sweet, are likely have elevated pH levels and are best kept out of the canning mix; sauce may be the perfect use for those that have been neglected on the counter or vine just a bit too long.
If I grow a tomato variety for enough years in my garden, and I save seeds each year, will it become genetically more adapted to my climate over the years?
No. A particular tomato variety has a specific set of genes that control how it grows, how it looks, and how it tastes. If, over a period of time, the tomato seems to change and adapt, it is likely due to either subtle changes in how it is grown, how the weather affects its growth, or even an inadvertent selection for different characteristics by the seed saver. For example, if half a dozen plants of a particular variety are grown each season and one plant does slightly better, and the variety is carried on by saving seeds from tomatoes only from the superior plant, something is likely genetically different about that plant. So, in this case, it isn’t that the genes are changing or adapting. Rather, a genetically slightly different tomato was found and is now the basis for refinement into a new variety.