Yes, there is a considerable difference. Plants actually use about 6X more P (middle number) than N (first number). So unless you know your soil is deficient in P, the 10-10-10 would be a better choice.

Of course, continually adding organic matter (compost) and mulching with an organic mulch will probably reduce your need for fertilizers to about nil.

The fertilizer #s are the %s of NP and K by weight. 10-10-10 is 10% each of NPK, while the 5-10-5 is 5% each of N and K and 10% P.

I wouldn't use a fertilizer (gardens/beds)
with a middle number higher than either of the other two numbers unless a soil test showed very low P levels, and I would never use them under any circumstances in containers.

Al

Al is correct in suggesting 10-10-10 is better than 5-10-5 for general use.

The mnemonic for N-P-K effect on plants is - UP - DOWN - ALL AROUND. That is, N is more responsible for plant growth above ground. P is more responsible for root growth. And K is more responsible for overall plant health. This is a simplification, but useful. So in spring a high N fertilizer gets the grass growing. If you have a new lawn, P should be higher to encourage root growth (16-20-0 for example) and in late summer, a high K number will make the grass healthier for the cold weather.

The percentages are for N, P2O5 and K2O. P = 0.436 x P2O5 and K = 0.83 x K2O. So 10-10-10 is actually 10-4.36-8.3 when speaking of N-P-K.

I always thought that nitrogen was the most needed fertilizer because of its volatility. The link shows that the N application rate is higher for all crops except for soya beans. Beans can fix atmospheric nitrogen.

Here is a link that might be useful: Fertilizer Use Statistics

Home depot has 10 10 10, is that ok or should I go to a nursery and get 5 10 5. I'm in NJ.
Thanks

Sorry, posted before the last response. If I get 10 10 10 do I need something else for the evergreens? Also, I don't want to ever fertilize. What about the Preen already on it.
Thanks

From what I can find, Preen is not a fertilizer. It's a pre-emergent herbicide. Never used it. I just get down on my hands and knees and pull weeds.

The 10-10-10 is probably a water soluble fertilizer. To prevent over fertilization, mix a 1/2 strength formulation.

I feel you are over thinking this. Plant, water, fertilize and go get a beer.

Plants actually use about 6X more P (middle number) than N (first number)

Cut cut cut people. Let's roll it back. Aaaaaand take two!

Cowgirl,
First thanks for the Up-Down-all around, being a gardener for most of my life, the one thing I could never get thru my thick head was how to keep track of fertilizer.

Second, Preen is made from Corn (at least what a master gardener told me). Its actually corn gluten and does have some fertilizing effect. I found this little tid bit and tried calling a local feed store for some, they asked what do I want it for, i told them my lawn (for fertilizing and crab grass prevention), they said it was $20 a bag. Afterwards a farmer told me that if I would have said for cattle feed I would have got it for $5 a bag. The reason is that Gluten was discovered by Iowa State U as a pre-emergent herbicide and they have a paten on it. Anyone using for pre-emergent herbicide has to pay royalties. This all being said its a pretty organic safe pre-emergent herbicide. The other thing is that if you live near a big ADM corn plant (or similar) you can get truck loads cheap. Unfortunately the closest to me is an hour away, and to save a few bucks for a truck load but to use $40 in gas to get it is a wash.

I beg a pardon - I misstated myself.

Correction - Plants use about 6X more N than P. Here's a chart (below) I put together showing plant's relative usage of nutrients. Essentially, all plants use the same nutrients in the same ratios with only minor variation. They just grow at different rates and use different amounts.

I gave Nitrogen, because it's the largest nutrient component, the value of 100. Other nutrients are listed as a weight percentage of N.
N 100
P 13-19 (16) 1/6
K 45-80 (62) 3/5
S 6-9 (8) 1/12
Mg 5-15 (10) 1/10
Ca 5-15 (10) 1/10
Fe 0.7
Mn 0.4
B(oron) 0.2
Zn 0.06
Cu 0.03
Cl 0.03
M(olybden) 0.003
To read the chart: P - plants use 13-19 parts of P or an average of about 16 parts for every 100 parts of N, or 6 times more N than P. Plants use about 45-80 parts of K or an average of about 62 parts for every 100 parts of N, or about 3/5 as much K as N, and so on.

Al

FWIW, only one fomulations of Preen is derived from corn gluten meal, the so-called "organic weed preventer for vegetable gardens". The rest are chemical based with trifluralin being the active ingredient.

The suggestions for fertilizing any permanent landscape plantings is to supply what is needed based on a soil test to determine what, if anything, is deficient under existing conditions and then supplement what may be lacking. It may very well be that NO fertilizing is called for at all. We tend to get caught up with the marketing efforts of fertilizer manufacturers who would have us believe that successful gardening is just not possible unless we fertilize repeatedly and often. This is simply just not true and unnecessary fertilization does more harm than fertilizing at all and the use of synthetic fertilizers in particular (like the 10-10-10 or even the 5-10-5) contribute heavily to pollution.

Since you've already used the fertilizer enhanced Preen, I would not use anything else unless you have determined a need for it by having a proper soil test done. Otherwise, Al's comment that "continually adding organic matter (compost) and mulching with an organic mulch will probably reduce your need for fertilizers to about nil" is about the most valuable and helpful piece of info in this thread.

btw, the mnemonic I learned for NPK is "shoots, roots, and fruits" :-) N takes care of the leafy growth (shoots), P addresses the roots and K encourages the development of fruits/seeds as well as the overall plant health and appearance.

How much of any "fertilzer" might need to be added to any soil can only be properly determined by a good, reliable soil test. Putting some, any amount, of any synthetic "fertilizer" can result in further pollution of our water because these very soluble materials will simply flow out of your soil with the water, unless there is adeqaute levels of organic matter in the soil to aid in holding those nutrients there and then, very probably, those synthetic nutrients would not be needed since the soil would have enough.
Get a good, reliable soil test before spending money on some 5-10-5 or 10-10-10 that you may not need or could add to the pollution of out world.