spring growth vs fertilizer

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Jan 12, 2004
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Being a beginner I find myself asking "why" alot. Most times I can find an answer here or on antoher board, but this one escapes me.

As is the norm, I applied fertilizer in the spring with everyone else and of course had more grass than my cows could eat. In late May I decided I would try to plant some warm season grasses into my cool season pastures and to do it I mixed it with 12-12-12. Actually got it spread in mid June and it really woke up those pastures.

So, given that most, if not all, have an abundance of grass in the spring AND most also fertilize in the spring wouldn't it be better to apply the fertilizer mid summer when growth slows down instead?

The short answer is that you would risk burning it up. The grass becomes stressed in the summer (less rain and more heat) and adding fertilizer would put additional stress on it. Even if it didn’t burn it you would not be getting the bang for your buck in fertilizer costs.

This has been an incredibly wet (and cool) summer so far, so don’t let the strange weather deceive you into thinking normal patterns are in place.

Most folks around here put fertilizer on a little early for my taist, March.
We wait till April 15th. we think we get more out of it at that time.
We too have had a wet year, usually we have to be careful about shooting off fire works on the 4th because of dry grass...not this year.

Most of the fertilizer timing issue is having the stuff available to the grass when it needs/can use it. Cool season grasses (CSG) make the majority of their growth by the middle to end of May. If the fretilizer is applied after that the plants can't/won't take advantage of it. On The other hand, WSG makes the majority of it's growth from June till August. CSG has another short growth period late September into the November and with fescue, the end of November.
While putting it on too early will cause the nutrients to penetrate past the root zone, in areas that actually have soil, putting it on too late will either waste it by not being available when needed. In worst case scenerio it will burn the grass.

The purpose of pasture is the vegetate state of the plant instead of the blooming/fruiting phase. So you can either put the fertilizer down as (or before) the plants are growing (spring or whenever if under irrigation) or as the plant/roots are regenerating in the fall, so it is available the following spring. (N)itrogen is needed for the vegetative, green, phase.
(P)hosphorus is needed for bloom/fruit production. Also if you are putting barnyard manure back on your grass pastures the P should build up over time if you do a soil test. You don’t want your grass to stop growing and go to seed. So unless there is some reason based on your growing location you shouldn’t need an equal amount P and K to your N. Most of the Chem companies are used to selling to veg crop growers or grain producers, which is why they try to sell you a balanced fertilizer. Also it should be far less expensive to just put the Nitrogen alone or with a little potash.
around here we need the (K) the lime... fall is best but anytime works..as long as you can work with it... this years grass crop grows well here in IL..mosty timothy.. donna
Here in central Texas we have to fertilize based on when there's a good chance we'll get rain. Which is why most everyone fertilizes in April and September.

Of course this year with the tropical weather system hanging around for a couple of weeks, we all ran for fertilizer buggies whenever it started clouding up!
This is a lot of great information, thanks. I should have stated the fertilizer was only for helping broadcast the seed, we only put 100 lbs per acre (which included the seed). That's why I was surprised it made such a difference. I use soil tests for my normal application of fertilizer so it really threw me when I applied this and it actually improved it more.

I guess it must have just coincided with the WSG growth and improved it.

That and the 3 weeks of daily rain didn't hurt either.

donnaIL":lhg90vrg said:
around here we need the (K) the lime... fall is best but anytime works..as long as you can work with it... this years grass crop grows well here in IL..mosty timothy.. donna

(K) is potassium
"ag-lime" may be all calcium or calcium and magnesium carbonates and is used, here on alfalfa, to correct soil acidity.

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