Gardening under the Oaks

by Nita Holstine

Recently there was a mention that Oak trees were not acidic and that their leaves were easily used in the garden. This comes from an otherwise knowledgeable person but they added that it was an old wives' tale. We know better.

During our 12 years now of gardening here in the middle of Texas, we have had some success and many failures. We can look back and know what went wrong and what was just right. Some spots do well for vegetables but need extra work and addition to the soil. 

Different oaks have different levels of acidity. I didn't realize this until I read about the acorns. CLICK HERE for more information. While some are sweeter, they must all be leached and drained to produce an edible nut for making meal. Their acid is called tannin. 

We have several different types of oaks. One is the Southern Red Oak and appears to be high in acid. 

Long ago, I had asked Byron Tumlinson about composting leaves and using them in the garden. He advised composting at a hot temperature for several months. When I asked about oak leaves he added that they should be aged longer, perhaps 6 months or so to lose their acidity. We don't have a shredder to chop them fine so the process would take a lot longer. We have the hot chicken manure but it is breaking down completely by the time the leaves are useable. 

If you've ever had blossom end rot in your tomato crop, you have acid soil in need of sweetening. The easiest way is to add wood ashes. Besides your usual compost and manure, it will give the tomatoes (or cantaloupe) the sweetening they need.

Some plants seem to love the acid of the oaks. CLICK HERE for lists and more details. Learn the damage that is caused to those who cannot tolerate the acid. The cucumbers don't mind the sap or root acid. Plenty of compost and wood ash for their roots and they do just fine. Perhaps they would do better not being in the shade of the oak but they are the only shade we have. With our hot scorching sun, they will shrivel and die in the mean afternoon sunlight.

We were given some periwinkle when we moved here. I had been looking for wisteria and this person said that's what it was. Yeah sure. It was periwinkle and did NOT like the first place I planted it. So, I went back to the plant wisdom book and found that they need partial to total shade so they were moved to a new spot. These few pieces in a 2 foot space are now spread over 40 feet by 20 feet. They'd take over the driveway if they could. The oak leaves fall on the plants and around them and they do oh so well. Only during the dry heat do they wilt and beg for water. They don't mind the sprinkling with our hard well water either.

I found a map showing that the natural acid soils were only in the eastern USA. We don't have soil. We have sand and every bit of organic material is added to the sand. We have thousands of oaks and if you've seen photos, we have little space that doesn't have oaks around it. Our only shade is in provided by the clumps of trees. The sap that is produced in the spring appears to be the very worst for plants like the tomatoes we are trying to grow. If we can protect the baby plants long enough, they can survive outdoors on their own. The cucumbers don't seem to mind the oaks at all, even the sap.

Byron Tumlinson agreed that even the roots of the oaks contained acid. So, the best we can do is to take out what roots we can, add the compost and manure and plant our baby plants. This year we have had one hail storm after another. And we'd gone perhaps 6 years with no spring hail. We went long without seeing any grasshoppers but now the babies are hatching and they are attacking with a vengeance. What to do about them? The oak acid doesn't bother them at all.