Saturday, March 17, 2012

When Seedlings Fail to Thrive


Plants, just like human beings show/manifest signs when in trouble or is sick.  
Here are common seedling problems and what to do about it:

Leaf Curl
·      Cause: Too much fertilizer will cause leaves to curl, especially in bright light.
·      Remedy:
o   Decrease or dilute the amount of fertilizer.
o   If the problem is severe, re-plant the seedling in fresh potting soil.

Yellow Lower Leaves
·      Cause: Too much fertilizer.
·      Remedy:
o   Avoid over feeding young plants.
o   I suggest diluting the fertilizer more and ensure good air circulation around the plants.

Leggy Plants. A leggy plant has large gaps or spaces between leaves and thin, weak stems.
·      Cause: Insufficient light.
·      Remedy:
o   Make sure the plant is getting sufficient light, but don’t let the temperature get too high.
o   Avoid overcrowding so provide ample spaces in between your plants. 

Leaf Discoloration
·      Cause: Off-colored leaves are often a sign of nutrient deficiency.
o    Pale leaves may be a sign of nitrogen deficiency or lack of enough light.
o   Deep purple veining can indicate a deficiency in nitrogen.
o   Reddish purple undersides can be a sign of phosphorus deficiency; the seedling may also be stunted with thin, fibrous stems. When the soil is too acid, phosphorus is not taken up from the soil.
o   Bronze or brown leaf edges can be a sign of potassium deficiency or overwatering.
·      Remedy:
o   Re-pot the seedling into a medium that contains compost. Compost is likely to contain the trace minerals plants need.
o   In my garden, I used soil substitute such as vermicompost & coco coir dust. I combine the two and my plants seem to be thriving well, whether I use OLF (organic liquid fertilizer) or it’s in the hydroponics set-up.

Discolored Roots
·      Cause: Overfeeding or overheating (too high temp) which can result in excess fertilizer salts being released into the soil.
·      Remedy:
o   Re-plant the seedlings in fresh soil or leach away the toxic salts. Use well aerated soil and do not overfeed or overwater.

Mold
·      Cause: Sign of poor drainage and lack of air circulation.
·      Remedy:
o   Scratch the soil to increase aeration, move seedlings to a place with good air circulation. You can also add powdered charcoal to the soil surface.

Insect Damage
·      Cause: Identify the insect at work. Prevention is always the best course of action.
·      Remedy:
o   Avoid overfeeding which can result in excessive green growth which can attract insects such as aphids.
o   Keep the greenhouse or garden free of plant debris which can harbor sowbugs, slugs, and snails.
o   Place plants where there is good air circulation to slow down spider mites.
o   Use yellow sticky traps (fly trap) to control whiteflies.
o   In my Hydro set-up, I keep insects at bay by enclosing it in a net.
    
Damping-off. Withered seedlings and plant failure is a sign of the fungal disease called “damping-off”. Damping-off attacks plant stems at the soil surface.
·      Cause: Too much nitrogen and moisture, or too little air circulation.  
·      Remedy:
o   Prevention is the only course of action: maintain good air circulation, avoid overwatering, sow seeds in a sterile medium.
o   You may pre-soak seeds in water with a tablespoon of clove oil or crushed garlic cloves added –these have anti-fungal properties.
o   Or better yet, pour boiling water over the planting medium and allow to cool before re-planting. It will help destroy nematodes or microorganisms thriving on the soil. 

Poor Root Growth
·       Cause:  Poorly drained soil, insufficient soil fertility, over-fertilization, temp. is too low, starting medium or soil insufficiently aerated.
·       Remedy:
o   Repot the seedling is sterile potting mix and protect the seedling from broad swings in temperature. Keep the soil mix just moist.


With special thanks to:
 Steve Albert
 University of California
 www.harvesttotable.com






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