Anyone understand fall lawn fertilizer and effect on plants and trees?

[scollins]

I would pay a visit to your local U of O County Extension Service agent for lawn fertilizer recommendations.

For recommendations on trees, your local Ohio DNR District Forester or local urban forestry specialist could advise you on fertilizer effects on trees.

Coniferous trees respond differently than deciduous trees to chemicals.

For instance, "Weed and Feed" contains broadleaved herbicides, like 2,4-D, that would sicken or kill hardwood trees.

[Cody Matthees]

It depends how your winters are.. Up here in the MN/ND border region the big 3 dates for fertilization with cool season grasses is Memorial Day, 4th of July, and Labor Day. If you send the grass going into hard winter in a lush growing state up here you are asking for it. It would be different for your region obviously. With the trees it's the same, the guys in the forestry dept at NDSU say spring is best and avoid lush growth going into winter.

[sixdogs]

It depends how your winters are.. Up here in the MN/ND border region the big 3 dates for fertilization with cool season grasses is Memorial Day, 4th of July, and Labor Day. If you send the grass going into hard winter in a lush growing state up here you are asking for it. It would be different for your region obviously. With the trees it's the same, the guys in the forestry dept at NDSU say spring is best and avoid lush growth going into winter.

Yes, that's true about lush growth going into the fall with plants and trees. My concern was about the incidental fertilizing into existing trees on the lawn area after they had gone dormant and if that would cause them to start to grow again. I don't know and the answer is confusing but fall is now evolving as the best option for fertilizing lawns here. The late root , but not top growth allows a lawn to better endure winter, as I understand it. In fact, current wisdom says to not fertilize in the spring at all since the excessive growth actually stresses the root growth in order to force top growth.

There is some great advice earlier in this thread from Nomad289 and DT86. Their info is my new bible but I am still am not sure about the tree thing. Since I have 600 trees planted within the past 10 years and they are my sole windbreak from dead-flat ground and high winds, I don't want to take an unnecessary risk. That's my thinking at the moment.

Calling an extension agent no longer works. The offices are barely staffed, have answering machines and someone will get back to you in a couple days. Answers are vague and the suggestion is always made to call a "Master Gardiner" volunteer worker. If I didn't know better I'd say they were trying to avoid any reference to work.

[LHS Inc]

For years I have read that the best time to put fertilizer on a lawn is the fall. OK, I'll go along with that but doesn't the nitrogen in the fertilizer give a boost to trees or bushes and cause them to act like they want to start growing again? I know that doesn't sound right but I don't know. Or maybe I just put down fertilizer with little or no nitrogen?

I happen to have my summer fertilizer that never went down because of the dry summer and it's something like 18-2-9 with the N being slow release. I'd like to put that down now but I have lots of trees that would get coverage and don't want to damage them. Maybe I wait until December when everything is for sure dormant? I don't know and am confused so if anyone understands this, maybe you could enligten me a little and offer some advice.

Oh, we are central-south Ohio and the grass seems to stay green to a degree for most of the winter.

A soil test will help you on how much fert you need to put down. It only takes a small amount of N to satisfy the grass. The MD recommendation for N on turf is 0.9 lbs per 1000 sq. ft.

If you were to fert in late Fall the little bit that gets applied to the trees and shrubs won't affect them at all. If they take it in it will be stored for the next growing season.

Only a prolonged warm spell will break the dormancy in the trees/shrubs. Fert will be there when its needed.

You should fert while the grass is still growing so it can take in the nutrients. I like to do it in October before the last couple of cuts. If you use a slow release it will take it in slowly without any surge in top growth.

Both Phosphorus (P) and Potassium (K) are for root growth with P being the more beneficial.

Its too late to apply fert now but you can still do a soil test and be ready for a Spring app. If you are leaving the grass clippings on the lawn they can account for up to 50% of the N the lawn needs.