Many sites advise not to fertilize in the winter. Will someone explain why? Excuse my ignorance but don't plants need their vitamins in the winter as well? It makes more sense to me use the recommended fertilizer at half straight once a month rather then not at all. Seems to me most plants are still growing in my back yard even through the winter.
Many Moons!
Rhapsody
It's best to fertilize during the growing season. You wouldn't want to encourage growth in winter when new growth could be damaged by cold weather.
Rhapsody616 - I think it depends upon what you are growing. I fertilize my broccoli plants ever two weeks or so. If I didn't I wouldn't get the huge (eleven inch) heads that I've been harvesting.
Personally, I don't fertilize anything that is "dormant" (such as fruit trees) until they break dormancy.
It's not that you'd encourage growth by fertilizing in winter, it's that NH4 (ammonium) toxicity is a very real threat when you fertilize at soil temperatures below 55* with fertilizers deriving their N from urea and/or ammonium sources (like ammonium sulphate). NH4 toxicity is very common in container gardening and often occurs early in the season when soils are cold but growers anxious to give their plants a 'nice fertilizer boost'. Even natural sources of N (especially blood meal) can cause NH4 toxicity in plants. Excessive levels of NH4 interfere with the uptake of calcium, but more commonly, ammonium is directly toxic to plants. Some symptoms are, reduced growth, interveinal chlorosis, marginal chlorosis or necrosis of leaves, and root system damage. The conversion of ammonium to nitrate is carried out by soil microorganisms that are inactive in cold (or wet) soil. When ammoniacal N is not converted to nitrate in the soil fast enough, the plant takes up too much NH4, which damages the plant. FWIW, excess NH4 in (particularly cold) soils also further (to the cold) inhibits the germination of most seeds.
Al
Thanks Al!
Yah! Thanks Al! Now is that going to be true for all plants. Like grass grow all year round here in Long Beach CA! Even my strawberries are on the move. And HoneybeeNC broccoli... Or should that simply be the rule of thumb.
HoneybeeNC- thanks for the input as well
homers- thank you as well.
Rhapsody, your soil may not be below 55 degrees. Or your grass is able to grow in cold soil.
I have Re read tapla's post and am absorbing what that means when adding manure and stable bedding to cold garden, as I just did...wow...
All plants are not created equal in their reaction to ammonium uptake. Some plants are better able to convert ammonium to nitrate inside the plant. These plants probably fare better in cold soils where urea and ammonium N sources are used.
Al
sallyg- I have st Agustin grass in zone 10a... every two weeks it needs to be cut! It grows,
It sounds like its warm enough to grow all year, and it is growing all year as you know. I'm thinking you fell victim to articles which give one flat rule assuming everyone's garden is a medium zone 6 or something like.
indeed! It was 82° today and it will be 49° tonight!
Didja have to rub it in? LOL! Cold weather has finally set in here.
Yes, all due respect to Bay City MI and environs!
It got down to 12* last night, but fortunately it's warmed to a balmy 17* already. ;-)
Al
Rub, Rub, Rub!!!! Long Beach is kind of cool because it stays fairly warm and when I want snow I drive 2 hours north and I am in Big Bear!
I looked on my tomato vines from April 2011 and I have flowers and green tomatoes.. same with my peppers!
Rhapsody
tee hee, CA is amazing that way!
indeed!
