When growing tomatoes, the ultimate goal is to get the richest crop possible with the best possible flavor. If you are growing indeterminate or "cluster" varieties (such as Big Boy, Oxheart, Cherry, Early Girl hybrid, or other heirloom varieties) pruning plants to remove unwanted buds and leaves is essential to so that all the nutrients reach the fruits. If, on the other hand, you are growing certain varieties (such as the Biltmore, the Heinz or the Patio), a massive pruning could be counterproductive.
Steps
Part 1 of 2: Deciding When to Prune Tomatoes
Step 1. Determine which tomato variety you intend to grow
Before proceeding with the cut, find out if it is a specific or indeterminate variety of plant. The latter grow in a very similar way to the vines, so they must be made to develop vertically along the supports and pruned to obtain a correct growth. their energy towards the fruits requiring less attention and maintenance. Here are some of the most common varieties of both:
- Indeterminate: Big Boy, Oxheart, Black Prince, German Queen, most cherry and heirloom varieties.
- Determined: Ace 55, Amelia, Better Bush, Biltmore, Heatmaster, Heinz Classic, Mountain Pride, Patio.
Step 2. Check for signs of yellowing
One way to know when to start pruning is to wait for the stem and leaves of the first group of flowers to turn yellow. When you notice this color change, you can start pruning.
Step 3. Identify any axillary shoots (or suckers)
Check for suckers on your indeterminate plant. These are small shoots that sprout at the intersection between the branch and the stem of the plant. If left to grow undisturbed, these small suckers will draw life from the rest of the plant causing a decrease in the amount of potential fruit. It may not always be considered a bad thing, but strategic removal of these sprouts will help your plant develop more fruit throughout the season.
Step 4. Check for flowers
It is a good idea to start pruning tomato plants early as soon as the flowers begin to appear. At this point the plant should be at least one foot tall.
Part 2 of 2: Using Appropriate Techniques
Step 1. Remove all axillary shoots and all leaves below the first flower group, regardless of your plant type
The aim is to get a stronger plant by helping it grow a single main stem. All this to make sure that most of the nutrients can reach the fruit instead of feeding the shoots that are destined to be removed.
- To get rid of an axillary shoot, grab it at the base between your thumb and forefinger, then fold it back and forth until it snaps off. This is best done when the shoot is young and springy. The small wound that is created in this way will heal in a short time. This technique is called "simple pruning".
- As for the leaves and stem under the first group of flowers: if you live in a particularly hot climate, you should leave them until they turn yellow. Their function is important because they help shade the soil until the plant is mature. If the plant is instead in a humid environment (such as in a greenhouse), remove everything below the first group of flowers in order to improve ventilation. Moisture makes it easier for disease to develop and can also make pruning cuts take longer, making the plant more vulnerable. Improving ventilation helps you protect the plant.
Step 2. Thicker suckers should not be removed, as they could damage the entire plant
In the case of axillary shoots thicker than a pencil, you can use "Missouri-style pruning": remove only the tip of the axillary shoot leaving a leaf or two to help photosynthesis and protect the fruit from the sun. The downside is that these shoots will develop requiring further pruning later. This method is suitable for larger axillary shoots - if the wound gets sick it will be further away from the main stem, and leaving a few inches of shoot will reduce the damage to the plant.
Prune axillary shoots throughout the summer to keep the plant healthy. Given the speed of growth, you should consider doing this at least once or twice a week
Step 3. For indeterminate varieties, let only four or five fruit-bearing twigs grow from the main stem, then cut off all other unnecessary shoots, leaving the top bud intact
On the contrary, choosing to keep more than four or five twigs will prevent the proliferation of healthy and numerous fruits.
- Make sure cluster plants are securely attached to supports once flowering has occurred. Without this type of precaution, the plant will develop along the ground giving life to unhealthy fruits.
- Plants belonging to the given variety have a predefined number of stems that will grow naturally, so no pruning above the cluster is necessary. If you did, you would end up removing twigs intended for fruit production and damaging the plant.
Step 4. Remove the yellow leaves
The fact that they are yellow is due to the fact that these leaves use a greater amount of sugar than that produced by themselves. As the plant begins to grow, the leaves at the bottom will begin to yellow and wither. This is perfectly normal and you can safely remove them as soon as you notice them. This will keep the plant fresh and clean, as well as reduce the chance of disease.
Step 5. Topping the plant
To get the best out of the last crop of the season, you need to cut the top of the plant. About a month before the first frost, or when the plant reaches the greenhouse ceiling, remove the top shoot. At this point in the season, the tomatoes that are growing will have a limited time to reach maturity, so all nutrients must be directed directly to the fruit.
Advice
Some varieties such as "bushy" do not need to be pruned (or even supported with trellises or anything else). This type of tomato grows compact, producing a "wave" of fruit over a two week period, and then wilts. While the so-called "cluster" indeterminate varieties grow in height and bear fruit throughout the season. Some common so-called "determined" varieties are Rutgers, Roma, Celebrity (called semi-determined by some), and Marglobe. Common "undetermined" varieties include Big Boy tomatoes, Beef Master, most cherry tomatoes, Early Girl, and most heirloom varieties
Warnings
- To avoid infecting tomato plants, remove the shoots with your hands instead of using shears. However, for tougher, older shoots, you may not be able to avoid using a blade; in this case you should sterilize it thoroughly every time you use it.
- If you smoke, wash your hands thoroughly with soap and water before touching the plant as smokers can easily transmit the tobacco mosaic virus to tomato plants.
