Organic Gardening Tips
Preparing the ground for transplanting is extremely important for disease prevention. Fungal and bacterial disease prevention is especially crucial for coastal gardens. Never compost any part of the plant and practice crop rotation each year when growing outdoors. Tomatoes love deep soil on the acid side for proper uptake of nutrients. I apply a well-balanced acid organic base fertilizer into each transplanting hole. Bury each plant deeply to encourage new roots to grow along the stem. Those little nodules on the stems of larger plants that you may have noticed can turn into roots if placed in water. A strong root system contributes to a plant's ability to ward off potential problems. Liquid fish fertilizer is applied after transplanting and a plant support system or tomato cage should be installed soon after.
As the first flowers appear, it is time to slow down on the nitrogen and give your plants liquid potassium and phosphorous to encourage blossom and fruit set. Potassium is crucial for tomatoes. Wood ashes are a good source, along with greensand. Liquid organic fertilizers are faster acting. Kelp is excellent at this time to ensure a good supply of trace elements.
There are two other elements important for fruit success. Calcium is required to avoid a nasty condition called blossom end rot. A usual source is dolomite lime but should not be used for tomatoes as it changes the ph balance. Ground up oyster shell is an excellent soil additive. I throw a good handful around the base of each plant and then water it in well. Magnesium is important for fruit set and production. Italian and English tomato growers have known this secret for ages, giving Epsom salts to their plants. A handful around the base of each plant or mixed into a watering can will give your plants all the magnesium they need.
Tomatoes are heavy feeders. Keep all foliage off the ground and use straw mulch around the base of all your plants. This keeps your moisture even and prevents splash back from the soil onto the leaves. Most of the fungal diseases come from the soil, splashing on the leaves and so beginning the trouble. Encourage good air circulation with staking and by giving ample room between your plants, at least 3 feet. Never water from above. Use drip irrigation or a watering wand to water only the base of the plants. Deep watering discourages fruit from cracking and allows the ripening fruit to develop their complex flavors. Too much water, just like too much fertilizer, interferes with the flavor development of your tomatoes. The idea is to strike a balance.
There has been much debate over the years about pruning outdoor tomato plants. It is always easier for a plant to grow leaves than to produce fruit! Too many leaves means too much nitrogen. Sunscald on the fruit is caused by insufficient leaf cover. It is not seen in greenhouse fruit where pruning is much more essential for the fruit to reach maturity. Always do your pruning on dry days to avoid potential fungus attacks. Use clean cutting tools, sterilize with peroxide ahead of time, to avoid contamination. On indeterminate plants, the ones that continue to set fruit and blossoms, the suckers that grow between branches can be removed to encourage straight plants, I don't make myself crazy trying to remove them all.
Nutrition is more crucial in greenhouse production than outdoors, so be prepared to fertilize longer before slowing down. The same applies to pot culture. Many heirloom varieties do fantastic in pots on your deck or placed anywhere in a sunny spot. Determinate varieties that are smaller and set all their fruit at once are the best for pots, along with cherry types and early season cultivars. There are also a large group of plants that can be classified as semi-determinate that max out at 5 feet or so but continue to produce through the season. This applies to a lot of the old time cultivars and most of the paste types.
Companion planting gives great results when applied to tomato growing. Try growing oregano and basil near your plants. Also a border of marigolds deters whitefly and looks great. An organic garden encourages beneficial insects to balance out any potential bug problems. If you do find trouble, insecticidal soap will kill whitefly and aphids. Apply on a sunny day under all leaf surfaces.
Easy organic potassium fertilizer. Potassium is an element not that easy to come by in commercial organic fertilizers. The main organic source of K is greensand, which is almost never available at your garden center, and is heavy to order and have shipped. If you have a wood stove or fireplace, you can prepare an excellent potassium-rich liquid fertilizer with minimal effort. Mix about 2 pounds of wood ash into a bucket containing 2.5 gallons of water. Stir vigorously, leave to infuse for half an hour, then stir again. Leave the mixture to settle thoroughly. Then skim off the floating debris and either decant the liquid from the solids at the bottom, or filter through a strainer or cloth. This liquid will contain about 10 grams of potassium per quart (although actual concentrations can vary). It can be stored indefinitely in a plastic jug. Use it undiluted at the rate of 1 quart per square yard to fertilize vegetables and flowers.