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Some Seeds Like It Cool

Others need warm soil to germinate

It just takes a few warm days for some gardeners to decide it’s time to plant the garden. Depending on what you plant, you may suffer for your haste.
    Some seeds will germinate in cool soils, but others will only germinate after the soil warms to 70 degrees. When those seeds are planted in cool soils, the seeds will often rot before they get the warmth they crave. Read seed packets for suggested germinating temperatures.
    Beets, broccoli, cabbage, carrots, cauliflower, collards, kale, kohlrabi, lettuce, parsnips, peas, radishes, rutabaga spinach and turnips can germinate in temperature as low as 55 degrees. However, beans, corn, okra, peppers, and tomatoes require soil temperatures of 70 to 75 degrees to assure uniform germination.
    To get an early start on warmth-loving seeds, some commercial producers pre-germinate the seed, priming them in a warm water bath of 80 degrees with air bubbles flowing through the water. As soon as the first root, called a radical, emerges from the seed, starch is added and the seeds sowed in soil. Once germination begins, growth continues. Growth is slow at first, but as the soil warms, the well-established plants have a jump start on seedlings that emerged from seeds sown after the soil warmed.
    You can prime your seeds in an open container with an inch or so of water. Place the container on top of the refrigerator, where the heat from the compressor will keep it warm, or on top of the hot water heater. Shake the container of water and seeds at least twice daily to add oxygen. When nearly all of the seeds have a small white root protruding through the seed coat, drain the water and place the seeds on a moist paper towel. Using a pair of tweezers, carefully transfer the germinated seeds into the prepared garden soil. Plant the seeds very shallow and only lightly cover them with soil. Do not allow the soil covering the seeds to dry. Keep the soil moist until the seedlings emerge.
    By pre-germinating seeds, you can gain at least two weeks in harvesting that first snap bean or ear of corn.
    Another method of obtaining an early ear of sweet corn is to sow the seeds in plug trays using a commercial potting mix. Many seed catalogs offer plug trays containing 60 to 100 cells. Each cell has a capacity of one-eighth to one-fourth cup of rooting medium. After filling the cells, press a single corn seed into each. Moisten the rooting media well and place the tray in a warm room or greenhouse. As soon as the seeds germinate, place the tray in full sun. The seedlings are ready to transplant into the garden when the plants are six to eight inches tall. Gently remove the seedling from the tray and transplant.
    Don’t try this with beans, as their roots cannot be disturbed once they are established.


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