Best bets when growing tomatoes
Two important factors when growing tomatoes is that they receive six to eight hours of sunlight each day, and that there is good air circulation around each plant. There are several other factors which are important when growing tomatoes, as well as the type of summer Mother Nature gives us. The tomatoes I am referring to in this article are the indeterminate variety, this is the vining type which most people grow. (Determinate varieties are a bush type which commercial producers grow because all the fruit gets ripe over the course of about one month.)
Tomatoes are big producers and like well drained soil which is high in nutrients. It is suggested that for each tomato plant, mix in five pounds of compost (like a five pound bag of sugar) into the soil before planting. Because blossom end rot is the result of low calcium, some people like to mix in a few oyster shells (or save your egg shells and mash them well) and mix in about one tablespoon with each plant. Blossom end rot may also be the result of inadequate moisture. If the plant does not get enough water it is unable to take up the calcium. Tomatoes will use one to three inches of water per week depending on the type of soil in which they are planted. Water generously once or twice a week if there is no rain. This makes the roots grow deep into the soil. If they get a little water each day, the roots will grow near the surface of the soil. If it becomes dry, plants will wilt and dry out quickly. Consistent even watering is important for tomato health and if they are shorted one week you can not make up for it the next week.
Tomatoes are divided into early-, mid- and late-season varieties. Early-season tomatoes reach maturity in 65 days or less from time of transplant. Late season tomatoes mature in 80 days or longer. The mid-season varieties are some where in between. Tomatoes will mature about six weeks after the first blossom is pollinated. Tomatoes do not like the cold. Night time temperatures should be in the 50s and daytime temperatures in the 70s before they will grow well. It is recommended that in zone 4 (the Twin Cities), tomatoes should not be set out until at least Memorial Day. We a zone 3, so ours should be set out still later in the season. Tomatoes are also sensitive to heat. If daytime temperatures are above 95 degrees and night time temperatures are above 75 degrees for several days, the pollen is killed and consequently the flowers won't set fruit and will fall off.
When planting tomatoes, dig the hole very deep, put in your compost and calcium source, and bury each plant so that only the top few leaves are showing. The leaves which are on the buried stem, will become roots and grow. I prefer to dig a trench and lay the tomato down and cover it except for the top leaves. The top which is laying horizontal on the ground will naturally turn up toward the sun in a couple days. All the buried leaves will turn to roots. Either way, the plant will be well anchored with a deep root system in place. Your plants should be placed about three feet apart. If you rows are close together you may want to go to four or five feet between each plant. This is important for air circulation. After the tomatoes are planted, water them well with warm water. The soil should be allowed to warm for a couple weeks and then a mulch of straw or grass should be applied. This will help to hold moisture in for the plants and help to keep the soil from splashing up on the lower leaves when it rains. As the plants mature remove the leaves close to the ground. Diseases from fungal spores begin when rain or water splashes soil on these lower leaves.
It is advantageous to support tomatoes with cages or stakes. If cages are used, they need to be sturdy or give the cages extra support with stakes or posts. If you stake tomatoes, they will need to be tied with twine, fabric or pantyhose to secure them to the stake. If you use stakes, you will need to put a post at either end of the tomato row, and run a wire above the tomatoes. Tie the stakes you are using for each tomato to this wire to stabilize each stake. Cages and stakes keep tomatoes off the ground and allow sunlight to reach more of the plant as well as air to circulate around each plant. Air circulation is especially important if the weather becomes humid.
Remove sprouts that grow in the "V" where branches come off the stem. You may also want to limit the number of stems which you want to use to produce fruit. This will produce fewer but larger tomatoes. However, excessive pruning will limit the photosynthesis necessary to create the sugar which sweetens the fruit. In our zone 3 it is advisable to remove the tips of each stem after Labor Day so that the energy in the plant will be used to ripen the fruit that is present. Otherwise the plant will continue to use its energy to grow more foliage and set more fruit, which will not make it to maturity.
Kyle Schulz is a Wadena County Master Gardener from Sebeka, and the regular gardening columnist for the Wadena Pioneer Journal.