NEIGHBORHOOD GARDEN FOR APRIL 18, 2009

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FERTILIZER MAY NOT HELP YOUR PLANT BLOOM!!!!

BY GEORGE EDGAR

 

          Gladys and I get many questions about plants that are not blooming like the owner wants, or is not growing as the owner thinks it should. Almost always they ask, “Should I add fertilizer?”

          I respond, “Fertilizer may not help your plant bloom!!!  In fact, too much fertilizer may be the reason the flower is not blooming, or the vegetable or fruit tree is not setting fruit, or the carrots and beets are all tops. Too much or too little fertilizer may be why it is not doing well. And if it is not healthy, more fertilizer may make it worse by putting more stress on the plant to grow.

          By Federal law, every container of fertilizer must have 3 numbers on the package. The first number tells you how much nitrogen (N) is in the package and expressed as a percentage. The second number is phosphate (P2 O5) and the third number is potash (K2 O). Nitrogen makes your foliage grow, phosphate is good for blooming and root growth, and potash is good for hardiness. Too much nitrogen in relation to phosphate on your roses, tomatoes, houseplants, or other blooming plants, trees or vegetables will encourage top growth and foliage rather than flowers. This is also true with radishes, carrots and other root crops like beets and turnips. And as I said above, if it is not healthy, more fertilizer may make it worse by putting more stress on the plant to grow.

          Lawn fertilizer is high in nitrogen in order to make the grass blades (foliage) grow. Do not use in your flower bed or garden, or around flowering trees or fruit trees. It works fine in a compost pile if you do not have much “green stuff”.  A good granular rose, flower, shrub, tree, and vegetable fertilizer is balanced. That is, the middle number is at least the same or higher than the first number. Most balanced fertilizers are 10-10-10 or 12-12-12 and have slow release nitrogen. (Also make sure your lawn fertilizer is mostly slow release so it lasts longer and does not burn your grass.) Miracle-Gro and other water soluble fertilizers for plants are usually at 15-30-15 and the nitrogen is not slow release so is used up within two to four weeks. This is fine if not used to excess. In the winter time I usually use only a 1/4 solution at a time. On some plants it may be only once every month. 

          Do not over fertilize your lawn or plants. This only weakens the plant as it struggles to use the nutrients, and makes the stems on flowers, and vegetables spindly and weak. Also, this stress invites disease problems and a weak plant invites insects. This is especially true this time of year on your lawn.

          If you believe the TV ads you might think that Miracle-Gro is the answer to all your garden problems including a plant not blooming. But remember that fertilizer is not the answer for a sick plant, and is not the treatment of choice when a plant is under stress. In fact, fertilizer may make it worse. Application of fertilizer to a plant that has insect injury or looks sick will only put additional stress on the plant as it tries to use the food to grow.

          What the plant needs is an accurate and informed diagnosis and the proper medicine. If you have a plant that is struggling, make sure you get an informed diagnosis from a plant specialist before applying a fungicide, an insecticide, or fertilizer. Or maybe it is under stress because of too much water or not enough water. After the proper diagnosis and treatment, and the plant is healthy, you can begin a fertilization schedule that is recommended by your plant specialist.

Copyright 2009

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EPSOM SALTS AND MICRONUTRIENTS IN THE GARDEN

BY GEORGE EDGAR

 

          I had a call a couple weeks ago from a reader asking about putting Epsom salts on plants. Epsom salts (which is Magnesium Sulfate [MgSO4 7H 2O]) can be a good source of magnesium for plants that need it. The indication of the need for magnesium is dark green veins and yellow between the veins in the leaf of the plant. Clematis sometimes gets yellow leaves which looks like iron chlorosis but it also may be magnesium chlorosis, or a deficiency of magnesium. 2-3 tablespoons of Epsom salts per plant could help. Gladys adds 2-3 tablespoons of Epsom salts to each rose bush every spring.

          There are 16 elements that are needed for good plant growth. Only nitrogen (N), phosphorus (P), potassium (K), sulfur (S), iron (Fe), and zinc (Zn) may need to be added to Nebraska soils. The rest are usually present in sufficient quantities. However, some fertilizers contain many of what are called micronutrients including magnesium. Most of these are organic fertilizers and made from plant material. Compost added to the garden contains many micronutrients.

          One of those other micronutrients is calcium. Many of us have a problem with blossom end rot on our tomatoes. Low calcium transport in a plant appears to be associated with blossom end rot of tomatoes. However, the addition of calcium to the soil or sprayed on the plant does not seem to help, as it is the transport of that calcium from the soil into the tomato that is the problem. Most of the time our Nebraska soils have enough calcium available for the plant. Research has also shown that one of the reasons for the poor transport of the calcium to the fruit may be irregular watering. That is we plant the small tomato plants and then go on vacation, or we forget when we watered and then over-water. This irregular watering makes the calcium go up into the foliage and not enough to the fruit. Don’t waste water by over watering and don’t waste your money by over fertilizing.

Usually only the first tomatoes are affected, as the plant itself uses the calcium that is available in order to grow. Then the second flush of tomatoes and all the later ones seem to be ok.

Copyright 2009

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COMPOST DEMONSTRATION

          Gladys Jeurink and George Edgar will answer questions about composting and other garden problems at the Earl May Nursery and Garden Center at 71st and O Streets in Lincoln on Saturday, April 18, 2009 from 10:00 am to 2:00 pm. Come and see a compost pile that George started using common items such as straw, leaves, shredded newspaper and shredded office paper. It will be on display all summer at the garden center where you can watch it transform into “black gold”.