Hello friends. Going to plant grapes in a couple weeks and forgot to do a PH test until today. Slick and nasty Carolina clay has a ph of around 9. Well now I wished I would have tested earlier. I did some digging around and threw some compost in the holes and built it up a bit. Given this information what should I do to give these grapes a good chance at survival?
In your situation you're best bet would be to make a bunch of pine biochar to amend the soil with. A pH of 9 is pretty basic and you need to get some acidity going for those grape vines. Most grapes like a pH of 6.5 to 6.75.
I would make up enough biochar from pines then grind that fairly fine, blend in any ashes from the burns too.
Spread this mix around every vine (more will be better both depth and circumference wise) then I would gently dig that into the top six to eight inches of the soil.
I would also watch the leaves this year, you can interpret what they tell you with a good book on grape diseases.
Don't forget to have your extension service do a complete soil analysis, you want to know which minerals (if any) are in short supply so you can do those amendments as the season progresses.
I like to do a blend of biochar, compost and green sand which I incorporate into every new bed I create.
Your amendments will probably be different than what my stoney, sandy loam requires, which is where the extension service complete soil analysis comes in to play. No sense in adding things that are already in good supply in the soil, all that does is get things out of balance and we want good balance so everything grows as well as possible.
hau. elle, biochar will tend towards the acidity/alkalinity of the wood type(s) used to make it. Hardwoods tend towards alkaline, that's why hardwood ashes are leached to make lye. Conifer woods and particularly pine, when turned into biochar will show the acidic tendencies of these woods. It is possible to create a near perfect biochar for almost any soil type/pH by using combinations. Biochar also benefits from being mixed with other amendments. In the situation of a soil pH of 9, clay loam soil, it would be possible to design a biochar blend consisting of pine biochar and the ashes created during the burn (would lower the pH towards the magic 6.5 number) along with what ever other amendments needed to balance the soils nutrient levels to what the plants need.
In the case of not having the benefit of a USDA National soil analysis (I got very lucky, my land is some that was included in one of those survey analysis) a comprehensive soil sampling sent to an extension service with a request for a complete soil analysis will give a person most all the information needed to properly amend their soil in a block by block set of amendments. One of the ways a lot of gardeners and farmers mess up is that they don't do a comprehensive set of samples, I lay out a grid on the area I am wanting an analysis of and draw a map of that grid. Then I label each square, take five samples from each square and jar them up with proper labeling so when the results come back I know exactly the hunk of dirt the numbers apply to. This way, you can actually get all your garden amended so it comes out in the end more homogeneous and so more productive.
Yes it will be more expensive than taking a bunch of samples then blending them into one overall sample but it also more beneficial to your soil in the garden since you are actually able to "spot amend" and so bring it all closer to proper balance.
I would check for powdery mildew and see if your soil has a potassium deficiency, the leaf in your photo shows signs of one or both. This is a link to a very good site that will be of help with grape problems; grape disease guide
Hey Scott, I'm in NC as well and will be planting some grapes in a few weeks. Thanks for this thread. FYI, after April 1 NC Dept of Ag does free soil tests. You just have to pick up the boxes/forms at your local extension office.
Location: North Carolina zone 7
posted 5 years ago
Great to know Jesse. Thanks for the tip.
Nothing makes sense until I venture outside
Diego Footer on Permaculture Based Homesteads - from the Eat Your Dirt Summit