If you don’t have a vegetable garden, you don’t have to give up homegrown tomatoes. Growing tomatoes is by no means limited to the bed and the greenhouse. Tomato plants also thrive excellently in tubs. Learn here all the important details about the appropriate pot size, the ideal substrate and the right planting.
What varieties of tomatoes are suitable for the pot?
Do not be afraid when choosing a variety: Growing in flower pots is not only successful with small balcony varieties, which grow just half a meter high (20 in). Larger bush and stake tomatoes also grow delicious fruit in pots with high-quality vegetable soil, the latter, however, must be well supported, ideally with so-called tomato columns made of wire mesh. Spiral rods are not suitable for potted tomatoes, as they do not find sufficient support in the potting soil.
One of the most important prerequisites for successful tomato cultivation is also vigorous young plants. Too weak or wilted specimens produce less yield and are more susceptible to plant diseases. So sow a few more tomato seeds and use only the best young plants for further cultivation.
Planters with good water drainage.
When planting in May or June, do not choose containers that are too large: pots that hold seven to twelve liters of soil are sufficient. Too much soil can lead to root rot, pots that are too small are difficult to control moisture and require more frequent watering on hot days. The planting hole should be deep enough so that the base of the stem is covered with soil to a height of 5 to 10 cm (2 to 4 in). This allows the plants to form additional roots on the lower part of the stem and to absorb more water and nutrients. But be careful with grafted tomatoes: the pot root ball should just be visible. Make sure that excess water can drain off well through openings in the bottom of the pot, because waterlogging will cause the roots to rot.
Where is the ideal location for potted tomatoes?
Potted tomatoes love warm places near the house, but not full sun. On unshaded south-facing balconies, the roots can overheat, often causing the plants to wilt despite moist soil. Some shade from a tree or parasol at midday is helpful. In addition, those who try to overwinter the tomatoes cultivated in pots, for this purpose need a bright location indoors or in a heated greenhouse.
A roof against leaf blight
Even though tomatoes are fairly easy plants to grow, they do have a serious enemy: leaf blight. It is caused by a fungal pathogen called Phytophthora infestans and can lead to high yield losses. Leaf infection is favored by moisture. Fortunately, there are some ways to reduce the likelihood of infestation: place your potted tomatoes under a canopy or in a special tomato house so they don’t get direct rain, and be careful not to wet the leaves when watering your tomatoes. You should remove the leaves near the ground as a precaution when your tomatoes have reached a certain size (about 30 cm / 12 in).
Sea salt provides more flavor
Although tomatoes grow strongly, it is best to give them only one dose of tomato fertilizer per week, dosed according to the package instructions. Long-term fertilizers prove to be unfavorable for potted tomatoes, as the release of nutrients depends on heat and water and is therefore irregular. An even water supply is also important, otherwise the fruits will burst.
On the balcony, with about five hours of full sun, the flavors typical of the variety can develop best. A fertilizer rich in potash and magnesium can further enhance the flavor. Moderate watering increases the dry matter content and reduces the water content. Scientists at the University of Pisa in Italy found that cherry tomatoes to which 12 percent seawater is added to the water remain smaller, but contain more flavors and antioxidants that are valuable for health. You can achieve the same effect if you also enrich the water with one gram of sea salt per liter when fertilizing your tomatoes. However, observe the reaction of your tomato plants closely and suspend the salt applications in case of doubt, because the soil must not become salinized, otherwise important nutrients such as calcium can no longer be absorbed.