What to Put on Tomato Plants to Help Them Grow, Seasonal Management of Tomato Plants

    Have you ever looked at a relative's or a neighbor's tomato plants and thought, "Why are their plants so much bigger, healthier, and more productive than mine?" You wouldn't be the first one to ask that question; but keep in mind that we all start somewhere on our tomato garden journey. It's also worth mentioning that it's possible they are growing hybrid varieties, which may be particularly productive- many times, hybrid tomatoes significantly outperform heirlooms- you just can't compare apples to oranges.

    You can still give your tomato plants the very best care, though- and that might be easier than you think it is. Tomatoes actually don't require a lot to become big and productive. Let's start with the seedling, the foundation of a strong, productive tomato plant. 

Starting Healthy, Strong Tomato Plants

    When I start my tomato seeds, I use a nice loose potting mix. Most recommend seed starting substrate, which is wonderful for avoiding disease and pests. However, I like to skip the steps of transplanting or fertilizing during their first weeks. Therefore, I go straight for potting mix. 

    Once the tomato seeds are planted, they will need warmth. After germination, they need adequate light and airflow. You want to be sure that the light is strong enough that plants don't become leggy. In addition, you want to encourage thick, strong stems. Do this by brushing your hand across the seedlings at least once per day or place a small fan on them. This mimics the wind, encouraging the young plants to build a resistance to the wind by strengthening their stems. 

    As the tomato plants reach 3 to 6 weeks of age, it's likely time to begin fertilizing. What to put on tomato plants to help them grow? Well, there are so many different fertilizers that you can use, but you should opt for a balanced, slow-release fertilizer. You want an NPK value that is fairly level. Something in the neighborhood of 10-10-10, for example. These numbers could be higher or lower, but you want them to be fairly equal during the seedling stage. You just don't want something That is very high nitrogen, very low nitrogen, very high phosphorus, etc. 

    One thing to be aware of is too much nitrogen. With too much nitrogen, the plants will grow very quickly but will put on weak stems. These stems could break easily during storms or under heavy fruit set. Of course, we all want big, beautiful tomato plants- But growing too quickly is actually a bad thing. 

Tomato megabloom that will produce large slicer tomatoes.

Transplanting Into the Garden

    Before you transplant tomato plants into the garden, you need to prepare the soil. Some till, some use raised beds with garden soil, some use deep mulch methods or lasagna methods, and some sink their plants into native soil, whether that be clay or loam. There's so many different ways to grow happy, productive tomato plants, But you just need to make sure of a few things: The container needs to be large enough to sustain the tomato and its growth if growing in containers, the area cannot remain waterlogged (such as low spots), you need full sun, you need some level of fertility, and you must eliminate competition for nutrients. 

    My situation tends to be a little more on the budget friendly side, I drop my tomato plants into some native clay, usually with a big scoop of black kow compost. Dropping an egg in is wonderful too, but wildlife tends to like to dig those up. A lot of people tend to also add eggshells for the calcium (Tums is another trick) and you can also add stuff like banana peels for the potassium. Lime can help to bring down soil acidity, and you could also sprinkle in some generic fertilizers to simplify the process. But my personal favorite way is good old compost and native clay soil. I generally till in compost from our goats and chickens too, but that's not an option for all gardeners. 

These tomatoes were transplanted into Dewitt woven plastic mulch (love this stuff!) and were grown on cattle panels. This is an excellent combination for high production and minimal weed maintenance. 

    The transplanting process usually coincides with fertilizing due to amending, but if you choose to put your seedlings into native soil without any amendments, you may want to consider top dressing the soil after transplanting. By the time the tomato begins to establish itself in its new home, the fertilizer will begin trickling down towards the root zone. If you just happen to be planting your tomato plants in an old chicken run or pasture, you may not need any fertilizer at all. 

Transitioning from Vegetative Growth to Flowering and Fruiting

    If you transplant your tomatoes between 4 to 6 weeks of age, you usually have a short lull where the plants are in a strict vegetative growth state. They require more nitrogen at this stage of growth, again, in the form of balanced fertilizer or compost. However, the first flower buds signal that you should begin transitioning from a more balanced fertilizer to one that has lower nitrogen. You can pinch the first buds so that the plant can continue focusing on vegetative growth, but there are usually more flowers coming in right behind them. Do not pinch flower buds on determinate varieties, though. If you're at a loss as far as which fertilizer to choose and you're new to gardening, opt for the various tomato blends that you'll find in the store. There are many different fertilizers that cater specifically to tomatoes!

    As they flower and fruit, tomato plants require more potassium and phosphorus than they do nitrogen. Too much nitrogen will give you lots of leaves and branches, but you'll quickly find that you're not getting flowers or fruit. You know how they say the grass isn't always greener on the other side? You might have seen stunning foliage on someone else's tomato plant, but did you look closely, and notice a large yield of fruit? People commonly over fertilize with the wrong fertilizers- And while those plants may look stunning, beauty doesn't translate into productivity. My most productive tomatoes generally aren't my prettiest plants.

Check out this megabloom! These tend to produce the larger slicers.

    It's actually a pretty important point to make- tomato plants are so much fuller, greener, and prettier during their first few weeks of growth, up until the first few weeks of fruiting. This is when they focus on their vegetative growth. Tomato plants tend to get spindlier as the season wears on; they're focusing on seed production at that point, or reproduction. 

Managing Foliage to Balance Health and Productivity 

    Here's the part where I put everything in reverse and completely turn you against all of that big pretty tomato foliage. I know, that's what you thought you came here for. But we're growing tomato plants, so let's grow some productive tomato plants.  We're going to largely exclude determinant varieties from this- somewhat. I'll discuss that later.

    Again, a big green tomato plant is beautiful. It's also asking for disease in humid climates. There are varying degrees of management that you could use, each with its own pros and cons.

Dwarf potato leaf tomato plant, with lots of foliage; typical of young, healthy tomato plants.

     You could absolutely wing it and not manage the plant at all. It'll likely grow 15 ft in every direction (an absolute mammoth of a plant), you'll see lots of spotty diseased foliage, the vines will root at every opportunity, and you will see lots of leaves, flowers, and fruit. With the fruit being so close to the ground, you're going to experience significant loss. Lots of bugs and rodents will take the opportunity to fill their bellies, and the tomatoes themselves can contract disease from the ground, particularly fungal diseases.  They will commonly rot before they ripen. Probably not the path you'd like to take. 

    There's a more middle-ground approach, you could trellis the vines upwards, usually on a cattle panel or within a tomato cage. You can let the tomato grow as it will with suckers and all and trim the vines back as they get too long. This is a common approach that most gardeners use. However, without pruning, those leaves can host disease, especially if there are several suckers that are growing in close quarters, such as in a cage environment. Low air flow quickly turns into fungal disease. You can get fairly decent production this way, you'll have lots of foliage, but it can be difficult to manage as the season wears on.

This tomato is the result of a mega bloom. Pretty cool process!

    Now, for my personal favorite method: pruning single or double leaders. Tomato vines put on suckers between the main vine and a leaf branch. These suckers will grow into additional leaders which will grow indeterminately, fruit, and flower. Too many leaders can strain the root system and lower production. With this method, you keep the plant down to one or two leaders, and all other suckers are removed. This significantly reduces the mass of the plant, and the leaves go with it. In addition, I remove all leaves below clusters of set fruits. So, if I have a cluster of green fruits forming 3 ft up the vine, there are no leaves from that point to the ground- the vine is bare aside from fruits. Leaves are generally removed before they have the opportunity to become infected with disease. I can also monitor for pests much more easily, which protects my fruits from pest loads that may get out of control before I realize what's happening.

    You cannot do these things with determinant tomatoes. Determinate tomatoes put on all of their foliage, flower, set fruit, and the plant is done. They don't keep growing; once they set flowers and fruit, that's it. You cannot train them down to a few main leaders without sacrificing significant amounts of your harvest, and you cannot prune all of their leaves because they tend to set their fruits at the same time, rather than over the length of the growing season. I do recommend trimming off any leaves that are in contact with the ground to greatly minimize disease, helping to protect your plant ahead of fruit set. 

I'm fairly certain this tomato was from the previous photo. Seltzer water for scale. This tomato is halfway through blush; I believe the variety was Amethyst Jewel. Amethyst Jewel is one of the best tomatoes, in my opinion.

Plant Maintenance for the Rest of the Season

    It is important to maintain a fertilizer schedule to maximize your yields and maintain healthy plants. Slow-release granular fertilizers last much longer than foliar fertilizers and are usually the first choice. When you apply liquid fertilizers as a foliar spray, the plant can use the nutrients much faster. This is a great option if you notice deficiencies. You can use the two in tandem, such as applying a foliar spray at the first sign of deficiency, while applying a granular fertilizer that same day to address the deficiency in the long term. 

    Don't allow weeds to overtake your plants. Other plants will compete for nutrients in the soil, water, sunlight, and they will also reduce air flow which will contribute to the risk of disease. Mulch or weed as needed. 

    Consistent watering is paramount. If your plants have periods of dry and wet conditions, especially long periods of dry weather, you may experience an outbreak of blossom end rot. A lot of people apply calcium when this happens, but that's not what the plants usually need; they usually just need consistent watering. When watering is inconsistent, the plant cannot uptake calcium properly. Therefore, they display symptoms of calcium deficiency- But they're not deficient because of a lack of calcium in the soil, they're deficient because they cannot utilize it (this exact same scenario happens with phosphorus and soggy conditions, as well.) Therefore, if you don't maintain a consistent watering schedule, you may wind up with significant losses. 

If these tomatoes would have been left until fully ripe rather than picking at blush like they were, it is very likely that these healed cracks would reopen with the next rainstorm.

    This next one will probably start a debate, but I recommend that you pick your tomatoes when they begin to blush. They retain their flavor and can be ripened in a window for that warm, sunny experience! If you're looking for productivity, picking at blush will stop a lot of loss. The tomatoes won't crack as they ripen (some varieties are susceptible to this), you'll alleviate the stress on the vine, and most animals won't bother tomatoes before they ripen fully (squirrels, birds, possums, rats, and more seek out tomatoes not just eat them, but for a source of water.) 

    If a plant falls ill from a viral, bacterial, or fungal infection, pull it. If you leave it in the ground, it could infect the other plants. Losing a tomato plant is hard, but it's much harder if that tomato plant causes you to lose several more plants. Move quickly if you see a wilted plant that doesn't recover within a few hours of watering. In these cases of wilt, be sure to dig out the root system and about 8 to 12 in of the soil from around the plant- largely the surface soil. This will help to prevent the spread. 

Preparing Plants for the First Freeze

    All good things must come to an end, and that includes the growing season. By the end of summer, most of us are completely over it. That goes for our tomato plants as well- If they've made it this far, they're usually pretty tired. 

    About 6 weeks ahead of the first freeze, begin terminating all main leaders and all suckers. Continue to terminate them as the season comes to a close. By doing this, you're forcing the tomato plant to focus on producing and ripening the fruits that are already on the vines. All energy will be redirected towards these fruits. This usually gives you larger fruits faster, allowing you to harvest them ahead of the final freeze. 

Tomato plant growing up to a cattle panel for trellising.