The Secret to Growing Heirloom Tomatoes

Heirloom tomatoes have gained in popularity in recent years. There are many reasons, first and foremost their unique flavour has no comparison to modern cultivars. We have been sold on disease resistance and uniformity by modern plant breeders at the sacrifice of true tomato flavour. Proper plant maintenance goes a long way to avoid potential problems when growing our heirloom beauties.

Good hygiene is crucial and should start at seeding time. Use sterile soil and containers for plant starts. The ideal temperature for germination is 70 degrees F. Start in greenhouse inserts, then cover seeds 1/4 inch deep. I start to transplant seedlings after the true leaves appear. Most plants average 4 inches tall at this stage. A 3 to 4-inch pot will give adequate space for the plants to mature. Liquid fish fertilizer is excellent to apply at this stage of development. Liquid kelp can be applied to soil and foliage during this stage of growth to ensure disease resistance.

Preparing the garden for transplanting is extremely important for disease prevention. Fungal and bacterial disease prevention is crucial for coastal gardens. Hygiene is essential, 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. If you have ever noticed those little nodules on the stems of larger plants, they 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.

As the first flowers appear it is time to slow down on the nitrogen and give your plants liquid potassium and phosphorus to encourage blossom and fruit set. Potassium is crucial for tomatoes. Wood ashes are a good source, along with langbenite or green sand. Liquid organic fertilizers are faster acting. Kelp is good 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. Oyster shell ground up is an excellent soil additive. I throw a good handful around the base of each plant, then water it in well. Magnesium is important for fruit set and to ensure a bounty of your favourite fruit. Old Italian and English tomato growers have known this secret for ages, they have given Epsom salts to their plants. A good handful around the base of each plant or mixed into a watering can will give your plants all the magnesium they will need.

Tomatoes are heavy feeders, though once you have followed this program, it is time to stop feeding and start grooming for success. Keep all foliage off the ground and use a straw mulch around the base of all your plants. This keeps your moisture even, prevents splashback from the soil on to the leaves. Most of the fungal diseases come from the soil, splashing on the leaves and the trouble begins. Encourage good air circulation with staking and giving ample room between your plants, at least 3 feet. Never water from above. Use drip irrigation or a watering wand to water the base of the plants only. Deep watering discourages fruit from cracking and allows the ripening fruit to develop their complex flavours. Too much water, just like too much fertilizer interferes with the flavour development of your fruit set. The idea is to strike a balance. In outdoor growing pruning, the plants themselves has caused a raging debate over the years. It is always easier for a plant to grow leaves than to produce fruit! It also indicates that too many leaves means too much nitrogen. Sunscald on the fruit is caused by not enough leaf cover and turns the overly exposed parts into a discolored mess. It is not seen in greenhouse fruit where pruning is much more essential for the fruit to reach maturity. Always do your pruning on a dry day 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. If you want to start extra plants, these suckers can be encouraged to grow larger and then cut off to start new plants!  That’s how versatile these plants are, remember those little nodules on the stems, they can grow roots anytime. Remove foliage from maturing fruit in the greenhouse and thin out extra branches that are not producing to ensure good air circulation. Mould and bacteria are more common in greenhouses without good ventilation and too high humidity.

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 which are smaller plants that set all their fruit at once are the best for pots, along with cherry types, and early season selections. 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.

Harvest time, our favourite time of year, a time to taste and test these wonderful treasures from the past. They come in every size, shape and colour imaginable!  Don’t believe for a second that these tomatoes don’t store well or ship well. Many of them keep fresh for weeks after picking and so do the green ones leftover at the end of the season. Never refrigerate tomatoes, they store much better at room temperature out of direct sun.

Here at Eagleridge Seeds, we have trialed well over 1000 heirloom tomatoes over the past 15 years. Through all kinds of weather conditions and cultural variations, including indoors, container and greenhouse production, these gems continue to amaze us with their diversity, disease tolerance and flavour. We have witnessed evolution in progress as plants adapt to all kinds of situations, especially climate changes. One of the oldest heirlooms, Calabash Purple has been changing to red, right before our eyes and in other parts of the country too. We are now maintaining over 200 varieties in our permanent collection and shall continue to explore and collect these treasures from all over the world in the years to come.

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 possible bug problems. If you do find trouble, insecticidal soap will kill whitefly and aphids. Apply on a sunny day, under all leaf surfaces. The fatty acids in the soap are also full of potassium, an added nutritional boost.

We encourage you to explore the rewarding enterprise of growing these tomato treasures. The health benefits have been receiving much publicity in the past few years, especially in important research into cancer prevention. Grow your own to prevent all those toxins in the commercial environment and support your local organic tomato grower. Cooking with tomatoes enhances their cancer prevention properties. Making your own pasta sauce is easy, and freezing it is much less time-consuming. The Mishca tomato is a paste variety I have been working with for the past 12 years. Through selecting the best fruit, over time, this variety has become my pride and joy for fast paste production. It cooks down in half the time to a very thick paste. Most other varieties cook down to sauce and prove to be much more watery. Although some sauce makers boil the fruit to remove the skins first, I find it easier to strain out the skins later after putting the paste in the fridge overnight. I save all the seeds, so they are scooped out first and set aside for the fermenting process that is required to prevent possible fungal diseases and to ensure germination for next year. The jelly seed coat that surrounds each seed prevents early germination in nature. In the wild, a tomato falls from the plant and slowly ferments, allowing this seed coat to break down. Without imitating this process, we will get very poor germination. Seeds are fermented in a warm spot for 3 or 4 days in small containers with lids. Add a small amount of water for small amounts. When mould starts to form, it’s time to wash the seeds. If you leave this process too long, you will sprout the seeds, or they will darken and rot. Add water to your container slowly. The debris and infertile seeds will float to the top, then slowly pour this out and you will be left with the good seeds at the bottom. Wash thoroughly and place on sheets of wax paper to dry. This avoids sticking. You can also place them on screen if you have a greenhouse, and let them dry for a couple of days.
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