Gardening Articles: Care :: Soil, Water, & Fertilizer
Soil Preparation for Root Crops (page 2 of 2)
by National Gardening Association Editors
Root crops taste better if they grow at a steady pace, and they need certain nutrients for this smooth growth. These nutrients are available in commercial fertilizers, which you can broadcast over the planting area and mix into the top two to three inches of soil.
The best time to add fertilizer is on planting day. If you wait more than a few days between fertilizing and planting, some fertilizer is bound to leach away or lose its potency.
Apply two to three pounds of a balanced fertilizer such as 5-10-10 for each 100 square feet. The numbers 5-10-10 or 10-10-10 refer to the percentages by weight of nitrogen (N), phosphorus (P) and potassium (K) in the bag of fertilizer, and they're always listed in the same order: N-P-K.
These three major plant nutrients are essential for proper plant growth. Nitrogen aids in leaf and stem production, phosphorus promotes strong roots and potassium also helps in root development by conditioning the entire plant.
Seeds are sensitive, and they can get burned by the nitrogen in any fertilizer that touches them. By mixing the fertilizer thoroughly into the soil, you can prevent that kind of accident.
The easiest way to avoid fertilizing mistakes is to always mix the fertilizer completely into the soil, and with root crops, to go easy rather than overdo it. Don't be tempted to add that extra handful of fertilizer. You may end up with no carrots at all - just lots of bushy tops!
You can aid root growth, however, by adding a little extra phosphorus in the form of bonemeal or superphosphate (0-20-0). Sprinkle it directly onto the rows just before planting the seeds, raking the bonemeal into the top inch of soil so it can be used by the young seedlings when they come up. A handful is about right for every four to six square feet.
Phosphorus won't burn the seeds, but the plants will only use as much as they need. So don't overdo it because excess will just go to waste.
You can also work a light coating of wood ashes into your soil before planting to ward off root maggots. Wood ashes can raise the soil pH because they are very alkaline, so don't overdo it. As with lime, the best time to add ashes is in the fall, but they may be added in the spring - they just won't have as much time to work. The right amount is four to five pounds per 100 square feet, mixed into the top two to three inches of soil.