Randy,
In general oaks in a healthy (natural) forest ecosystem do not need fertilizing and in fact may be harmed by too much nitrogen. Trees make their own food by photosynthesizing. Acorn production is a result of the sugar made by the leaves and transported to the roots for storage. Some of the energy (sugar) produced is used to increase twig and branch growth, root spread and leaf surface area.
So, cultural practices that enable forest trees to expand their crowns by removing adjacent trees that are competing for crown space do the most good in influencing mast production. This is called timber stand improvement (TSI). A forester from the Texas forest Service or a local consulting forester could help you with that.
For trees growing along the edge of a field or in a pasture, food plot, or opening you can potentially help acorn production by fertilizing the trees that are proven mast producers. Trees growing alone or in a small clump or in a line along a field often produce the most acorns. Trees in crowded woods produce less acorns per tree but may still produce more acorns per acre.
To fertilize trees in an opening, apply about 2 to 3 pounds of 13-13-13 per 1,000 square feet of area from just outside the the drip line (outer perimeter of the crown) to within about 3 to 5 feet of the trunk. Apply in early spring about one week before to one to two weeks after bud break. Or, buy the tree fertilizer spikes targeted to landscape trees and follow instructions. The tree spikes are more costly but easier to transport. It is important to get fertilizer to the trees roots and not to the grass and weeds. Its important to control grass and weeds growing within the drip line with Roundup (41% Glyphosate). Mix 2 ounces per gallon of water in a backpack or hand held sprayer and spray grass and weed foilage to the point of runoff. Some people "scalp" or mechanically remove the sod but you want to be careful not to damage the trees fine shoestring like feeder roots that take up moisture and nutrients. The large roots primarily anchor the tree and provide support. Anything that compacts the soil or removes the upper soil layers does harm to these fine feeder roots and ultimately impacts acorn production. Cattle or horses congregating around trees can compact topsoil as can heavy equipment or grading. Also, natural cycles of weather that negatively impact flower production and pollination affect acorn production. Also alternating cycles of insects that bore into the nut and lay eggs that hatch into larvae that eat the fruit affect mast crops. So fertilizing doesn't work every year. You have to stick with it and look for results over a period of years by targeting trees you have observed to be producers.
On leased land you are of course going to need landowners permission to perform the cultural (TSI) practices that have the most beneficial impact on tree health and acorn production. I have noticed increased acorn production on oak trees with and along food plots just from the annual application of fertilizer for the food plots. Same thing for trees growing in a fence line along corn or crop fields that get fertilized annually. Oaks growing in clover and alfalfa, which are nitrogen fixing plants (legumes) also spill over benefits for oaks by self fertilizing.
I have seen some impressive results from fertilizing with 10-10-10 (or triple 13 or 19) along roads or edges or lines through clearcuts where there is soft mast (greenbriers, blackberries, pokeberry, hardwood sprouts...) . Some foresters I met at an Auburn conference years ago shared how they hang stands in residual trees in or along recent
clearcuts and broadcast fertilizer around the stand. The tree sprouts, briers, etc. respond and so do the deer.
Topic: Fertilizing Oaks ??? (Read 2310 times)
