Monday, September 21, 2015

Questions about fertilizing and pruning muscadines

Q. My parents live in Avon Park, FL. They told me that the muscadines didn't make this year and I was doing some research and came across your Youtube videos. Any idea why they didn't make?

A. There could be several reasons for not bearing this year, including late frost, lack of pollination - perhaps a nearby pollinator died, failure to prune for several years, lack of pollinating vectors.

Q. Do my parents need to fertilize the muscadine plants? (10-10-10 fertilizer 6 inches from plant and around the plant) With what and what time of year to add fertilizer.

A. If the plants are not putting on much new growth, they might need some 10-10-10. A soil test might indicate the need.

If the plants have any age on them at all, putting fertilizer 6 inches away from the plant will do little good. The roots are shallow and run a long way. It would be best to broadcast the fertilizer around the plants as much as 3 feet or more. Casting the fertilizer with a gloved hand or a lawn fertilizer spreader will work. Fertilize early spring.

A soil test might indicate the need for magnesium sulfate - Epsom salt. You can broadcast some even without taking a soil test. Epsom salt is like chicken soup for some ailing plants. It might help; it can't hurt.

Q. Pruning what time of year?

A. Prune during dormancy with leaves off the plants so you can see what you're doing. That would be from early December to early March. Actually, you can prune other times of year, too. The problem would be knocking off young flowers and fruit. Muscadines will not "bleed to death."

Q. Who can we call to have someone check out the soil pH and check for diseases of the plants?

A. You can do collect a soil sample yourself. Drop by your closest Cooperative Extension Service office. Request a soil sample bag. Add soil to the bag per instructions usually printed on the bag. Return the sample to the Extension office. You will be charged a nominal fee. The office in Highlands County, FL is at 4509 George Blvd., Sebring, FL 33875. A horticulturist with the Extension Service might be persuaded to take a look at the plants to look for diseases. In most cases, muscadine diseases - mostly fungal - aren't worth worrying about.

Monday, April 20, 2015

Large black worms attacking in large numbers...

1st instar larvae on Vitis rotundifolia

Help again? I was checking the vines this morning and there are small black worms attacking in large numbers the leaves of the scuppernongs and muscadines.  I would assume this is some sort of moth or butterfly larvae, but cannot find suitable information on the internet.  Any ideas would help.  I hate to attempt to get rid of them with the wrong pesticides if I have to use them at all.

They might be Hyalophora cecropia , 1st instar phase. I can't tell if the ones in your photo are as "hairy" as the ones in the links below.

The reason they don't show the coloration and size that you might see in photos of the big, green caterpillars is due to their immature phase.

I don't think you need to bother getting rid of them. More grape leaves will appear. They won't denude your vines. There are probably enough predators to keep them in check. Some type of BT dust might benefit.

Return to

Monday, March 2, 2015

My seedless grapes are loaded with seeds and are very tart!

I planted a 30' row of various seedless grapes like Thompson and several other seedless varieties (I can't remember the names right now) that I purchased a my local Sam's Club. The seedless? grapes are all loaded with seeds and are very tart even after four years of growth.

First, you should know that even "seedless" grapes produce vestigial seeds. The size of the vestigial seeds can be influenced by climate. Second, climate can affect taste. It's possible that your climate simply isn't conducive to growing good quality seedless grapes.

If the grape varieties are not the color that they were supposed to be according to variety, it's possible that you didn't get the varieties you thought bought. The plants could have been mislabeled.

Return to

Muscadine vines stopped producing crops.

I have a 110' run of old muscadines that were planted about 1985 on a single wire trellis..  I have only lived here since 2006 and have been trying to have a good annual crop.  My first year pruning was very vigorous since they had not been pruned for about three years and there was a lot of old vines and dead wood to remove.

I have been having a good crop up until three years ago.  But since 2012 my crop has tapered off to almost no muscadines.  I am now getting very long new runners each year and also seeing more undeveloped 1/4" fruit as late as mid September, my normal picking time.

I have experimented with changes in  watering pattern, fertilizing, but nothing is helping produce more crop.  Three years ago I counted over 30 gallons of great muscadines that were produced.  I had so many after my family and friends had enough I put out road side signs and sold plenty.  in 2014 I only had 4 small ripe muscadines.

About four years before my crop tapered off to nothing,
I planted a 30' row of various seedless grapes like Thompson and several other seedless varieties (I can't remember the names right now) that I purchased a my local Sam's Club.    The seedless? grapes are all loaded with seeds and are very tart even after four years of growth.
I also have a garden about 30' away that is about 130' X 40' that has stopped producing some crops like squash, and cucumbers.  The corn, beans, peppers, tomatoes are fine.  The lay-out is muscadines, then grapes, then garden.

So I am thinking two things, one- that the seedless grapes cannot coexist with muscadines, and two- I have seen almost no bees in the muscadines, grapes, and garden in the last several years.  I also do not use pesticides in the same area.

Even my neighbor about 1500 feet away is also not getting many muscadines.  He normally has enough to make annual wine.

My vines  normally produce large bronze and large dark purple fruit.

Do you have any recommendations about what to try to improve my muscadine no fruit situation?

Thanks for your help.

Also, great job on the three muscadine pruning videos. Thanks

Muscadine production depends on several factors including plant sex, pollen availability, pollen viability, pollination vectors, available nutrients, soil pH, disease and moisture. I won't go into great detail on any of these subjects, but will remark about how I think they might apply to you. I won't remark on pollen viability at all because it's too complex, and probably doesn't apply, anyway.

Muscadine varieties are either female or hermaphroditic. Female varieties do not produce pollen. Hermaphroditic varieties, also called "perfect-flowered", have both male and female flower parts, so they pollinate themselves and others. However, even "perfect-flowered" varieties benefit from cross-pollination. Since you and your neighbor both had good crops of muscadine grapes in the past, there must have been adequate pollen and pollination. If either or both of you lost grape vines, then you might have lost a source of pollen. However, I doubt this is your problem.

If pollen is available, muscadine pollination is achieved by insect carriers (vectors) and wind distribution. Insect carriers are most important. There are various opinions about which insects are most responsible for muscadine pollination. In my opinion, native wild halictid bees are most important. Regardless of which, pesticides can do damage to insect populations. Though you do not use pesticides in the area, keep in mind that other users might be reducing the pollinator populations.

Important macro nutrients include nitrogen, phophorus, potassium, calcium, magnesium, and sulphur. Important micro-nutrients include boron, zinc, iron, molybdenum, copper and manganese. Micro-nutrients elements become extremely important if they aren't present in sufficient amounts. Magnesium deficiency is very common in muscadine grapes. Boron deficiency will certainly reduce grape production. Magnesium deficiency will show up in a soil test, if you request a test for magnesium. Testing of leaf samples will indicate boron deficiency.

Even if present in sufficient amounts, most nutrient availability is reduced significantly if soil pH is too low or too high. Soil pH between 5.8 and 6.5 is best for muscadines. A soil test will indicate whether the pH needs to be adjusted, and tell how.

Mildew will impact grape production. Of course, high humidity contributes to the presence of mildew. If small grapes begin to form, but fall off prematurely, you might have a mildew problem. Fungicide application can help.

Now, here are some random but specific comments regarding your situation.

The presence of your seedless grape varieties have nothing to do with your muscadine grape production.

The absence of bees might account for some drop in fruit production in your muscadines, squash and cucumbers. But your corn, beans, peppers, tomatoes are fine.

Squash and cucumbers are prone to mildew infection. Since your muscadines, squash and cucumbers are not producing, perhaps mildew is your problem.

That brings me to what you said about "getting very long new runners each year and also seeing more undeveloped 1/4" fruit as late as mid September, my normal picking time." If you are getting very long runners, it's possible that you're applying too much fertilizer - especially nitrogen - and irrigating too much. Together, they can contribute to a rise in humidity and encourage mildew. That would also explain the late, undeveloped fruit.

To be brief, take soil samples from around your grape vines and vegetable garden to your nearby Cooperative Extension Service office for testing. In addition to macro-nutrients and pH, have them check for magnesium.

I expect you can stop fertilizing, at least this year. Don't irrigate unless weather conditions become very dry for an extended period of time.

I hope this helps.

Thanks for your compliment about the videos.

Return to

New tiny muscadine grape clusters fall of before they get to "BB" size?

I'm in NE Tallahassee and have 6 muscadine vines about 8 years established. I got them from FAMU vineyards and have them post supported on a wire about 5' high x 60'. I have a drip line mounted about 2' above ground right down the center. I trim as you showed in your most informative video on you tube. The past few years I had tons of new tiny grape clusters come on and then the majority die or fall off before they even get to bb size. I read somewhere I should have a drip line set up that is 2' on each side of the centerline and only have individual runners by each vine. I just have an inexpensive drip hose with holes every 18" or so and try to set it for one-3 hours per day depending on rain. Any advice you can offer will be greatly appreciated.

Here's a blog post I wrote about grapes/flowers falling off.

Muscadine roots run shallow and wide, so drippers at the bases of the plants only benefit them when they're young. It's possible that lack of irrigation isn't your problem, though. See if boron deficiency or mildew is causing the drop. High humidity contributes to mildew. It's possible that daily irrigation.

In my opinion, your vines shouldn't need daily irrigation at 8 years of age.

Return to

Sunday, March 1, 2015

Should I till the soil around my suppernong grapes?

Should I till the soil around my scuppernong grapes?

You didn't say why you want to till the soil. Please, let me know why.

Anyway, I guess it depends on whether your scuppernong grapes are old or young. First, you should know that muscadines and scuppernongs are the same species. So, if we're talking about muscadines or scuppernongs, we're talking about the same thing. The roots run shallow and long. Many muscadine roots run less than 4 inches beneath the soil. If your plants have any age to them, you'll probably cut up necessary roots as you pass. Don't till. Leave them alone.

Return to