Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Blossom End Rot (BER): Blossom End Rot causes large brown or black dry or sunken spot(s) to appear, usually starting at blossom end (opposite the stem) of the fruit. Fruits often ripen prematurely. BER occurs when a plant cannot metabolize the calcium it needs to develop properly. This can occur when there is not enough calcium in the soil or when root damage and water stress reduce the uptake and movement of calcium through a plant. Occasionally, BER is the result of excessive nitrogen fertilization. It only takes a day for a lack of calcium to affect fruit, and that day can occur any time after blossom set.
- Once a fruit has BER it will not recover. The plant is still healthy, just remove the affected fruit from the plant. The fruit is still good to eat if you remove the affected part.
- BER most frequently occurs on fruit produced earlier and later in the season as this is when natural fluctuations in precipitation and cold weather occur.
- To avoid BER, properly site and prepare your garden bed before planting. Most crops need full sun and loose, well-drained organic soil. Make sure soil pH is slightly acidic, between 6.2 to 6.8, for optimum nutrient uptake. Test your soil to see if calcium is recommended. If it is, apply lime in the recommended quantity according to manufacturer's instructions.
- Avoid planting too early in cool soils as this can inhibit early root development, making the plant more susceptible to BER. Start with a quality transplant: a healthy seedling with strong roots will make a healthy plant.
- Avoid wide fluctuations in soil moisture by applying 2-3 inches of mulch. This will moderate the release of water to plant roots, and also keep the soil from drying out when it is directly exposed to the sun.
- Avoid drought stress by making sure your plants get at least 2 inches of rain or water per week. Apply enough water to moisten more than the top inch of soil. Container grown plants will need more than 2 inches of applied-water per week in hot weather, check them daily if possible. Consider using drip irrigation or soaker hoses. One or two soakings are better than many light waterings.
- Avoid over-fertilizing during the early fruiting stage, especially if the fertilizer contains high percentages of nitrogen. Use fertilizers especially formulated for tomatoes. These fertilizers have just the right amount of nitrogen and other micronutrients best for fruit production.
- Avoid close cultivation around the base of plants when weeding. A layer of mulch should help prevent the possible disturbance or damage of fragile roots accidentally.
Fruit Cracking: This indicates that when the fruit was forming, it did not get an even supply of moisture from the roots. A sudden rush of water from sudden and heavy summer rains through the stem can pop the skin of a ripening fruit like an overfilled water balloon. The condition is particularly pronounced after a drought when a summer storm delivers a great amount of water to the tissues in the fruit. The skin cannot expand fast enough and cracks appear. The crack may rupture allowing the entrance of blight and rot. Burpee Recommends: Take care with your watering: instead of a quick sprinkle every day, water deeply once or twice a week (depending on rainfall) so the moisture soaks deeply into the soil where roots can take it up as needed. Soaker hoses can help here. Stick your finger into the soil every day to check that it is evenly moist a couple of inches below the surface. Always mulch tomatoes to keep moisture from evaporating, even in containers.
Nematodes: Microscopic worm-like pests that cause swellings (galls) to form on roots. Plants may wilt or appear stunted. This is a serious problem in many Southern states. Burpee Recommends: Do not plant into infested soil. Grow resistant varieties. Try planting ‘Nema-Gone’ marigolds around your plants.
Tomato Horn Worm: Large, green caterpillars can quickly devour foliage. Burpee Recommends: With sturdy gloves on, hand pick them. If you see white projections coming from the back of the caterpillar, do not destroy it. These are the egg cases of a parasitic wasp that will destroy the caterpillar. These wasps should be allowed to remain in your garden.
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