I just fertilized my apple trees with some urea. They are fully dormant and the weather is cold...I assume it should not hurt them. I planted them in spring '07 and was away for 7 months, they were well watered and fertilized once in april '07. They did not grow too much and it's main stem did not get any thicker. I'm hoping the tree will consume this nitrogen and produce better growth in the spring. Do apple trees usually grow this slow? I have a farm in europe and water very young olive trees every 15 days and use 20-20-20 fertilizer each watering...and the results are visually obvious that there is new growth each time I water and fertilize.
is your soil deficient in nitrogen? a soil analysis is the only way to determine the mineral needs. Some plants will give visual indicators of mineral deficiencies but unless the deficiencies are major, its not an easy thing to determine visually. Slow growth could be caused by pH imbalance, lack of water, excess water, poor drainage, soil compaction etc. Adding urea nitrogen may have nothing to do with the 'problem'.
Fertilizing hardy deciduous stock with urea in the fall is a fairly accepted practice, at least in commercial nursery growing. Research has shown that these woody plants do not absorb any nitrogen until well into spring each growing season, and fall applications of nitrogen will be stored for better growth the following year. A soil test is also normal practice in an orchard...tho I hesitate to put much stock in a nitrogen test personally. If the other factors Paul has mentioned are attended to, I do find the plants themselves indicate the nitrogen situation, and sluggish growth and yellowing are likely signs of deficiency, with nitrogen being the most common "problem" element...just my opinion, smile... Gardenlover, I really doubt you've hurt anything by applying urea now, but with your climate I'm fairly sure the trees are unable to use this nitrogen. Over in my area of the world, urea applied now would be almost totally leached out (wasted) by spring...your colder weather may at least keep it in the root zone till next growing season. My recollection of fall urea applications is that it's done around September, while soil temps are good and the trees are still active, tho "thinking" about dropping their leaves.
thanks for the reply Growest! In southern europe if nitrogen was apllied this time of year to an olive tree...it is a gamble because there is sunny and mild weather year round and there is a chance of frost damage in february. But this being canada and the tree is already dormant, I decided to try this. I think if I applied it in september it would have sent out lush growth and it would be dead now with the colder weather. I really doubt the soil is deficient in any element. I have tested other parts of the garden and every nutrient was exceptional in amounts.
Yeah, you sure don't want your trees shooting out lush new growth that will get damaged when winter comes...September was just a guess from the photo's I recall...the leaves were just starting to senesce...maybe in southern Ontario that would be October? Early enough to allow the roots to uptake things, but late enough to avoid topgrowth would be perfect I guess.
