Kiwi Problems
Question from Mary:
my kiwi vines, both male and female are exhibiting the same symptom: the leaves in the sun are turning yellow from the middle out, then drying up completely, dying and dropping. At first I thought it might be mildew, given a very wet spring here, but several applications of Serenade did absolutely no good, and the leaves under the arbors on which they are growing are OK. I thought it might be sunburn, but full sun is recommended. The female produced fruit for the first time this year, by the way. Both plants were fertilized well this year and deep watered every two weeks (while I am upgrading my rrigation system–normally they would be watered once or twice a week). Many thanks for any ideas!
Answer from Pat:
Kiwi vines are subject to salt burn in alkaline soils. They also prefer regular irrigation and good drainage. They do well in sandy soil. Sometimes vines get spider mites. (Wash off webs and squirt foliage with water.) Good watering and fertilizing can help them cope with these problems. Bad drainage can cause yellowing of leaves which later drop. You may have overwatered while water system was unhooked.
Kiwi’s as you know are deciduous and depending on the weather their foliage may begin yellowing and falling earlier than usual. It is October now—autumn—, and thus the falling leaves may be totally natural. Keep a record of when things flower in your garden and when leaves fall. It may vary from year to year depending on day and night temperatures. A cold snap is enough to trigger leaf fall.
This is an additional note to what I wrote you before. When I checked your query and my answer I noticed again the fact that you are upgrading your water system and that the plants began dropping leaves earlier in the year. This seems like a major clue. Instead of regular irrigation, perhaps twice a week, you have been watering deeply but only once every two weeks. Perhaps you are letting the vines go too dry. That certainly would cause yellow and dropping leaves. Instead of telling you that you might be overwatering I think I should have suggested you might be under-watering. Also the watering you are doing by hand may not be reaching roots that grew during the time the plants were dependent on a sprinkler system. Kiwi vines need regular irrigation. They are not drought-resistant vines.
Pat, I just read this additional observation. Yes, they had been watered twice weekly in recent years (a practice that I started after reading “Roots Demystfied” that was corroborated by our UC Davis Ag Coop agent here), and perhaps this is the problem. Thanks so much–I will check it out!
Thank you so much for your thoughtful reply.
Your reply to my answer to your question is very interesting and covers a variety of subjects. For example, I am glad to hear there is an OMNI-certified soluble gypsum which would indicate that sulfuric acid derived from the petroleum industry was not used in the process of making it soluble. (This has been one of the major objections of purist organic gardeners against soluble gypsum. Rock gypsum is not nearly as effective, if at all effective.)
I will hone in on the one question you asked about humic acid. I think of humic acid as a remarkable and relatively new (1960’s first experiments in agriculture, 1980’s first used in gardens) miracle product for use in agriculture and gardening. The main effect it has is to cause the roots of plants to proliferate. Thus it is an extraordinarily effective planting and transplanting fluid, (unlike Vitamin B products which do absolutely nothing, which was long ago proved by scientific tests.) I always apply diluted humic acid when planting vegetables from transplants, especially transplants of the cabbage family (cole crops) since I find it hugely increases the health and vigor of the plants and thus the harvest. Humic acid also tends to release minerals in the soil, as I remarked elsewhere, so that plant roots can absorb them. Thus it is helpful in clay soils to give plants iron and other minerals that are already there but are often locked up by alkalinity or other soil chemistry and thus not in a form plant roots can use. In very sandy soils there are no or few minerals to be released but I have sandy soil and find the root-proliferation effect is extraordinary and I find that humic acid seems to increase all-over plant health. So actually I would recommend applying it when you can afford it to any plants when you want to activate their roots and promote vigor.
Regarding gypsum and the calcium that is in it, adding straight calcium would not do what gypsum does. In the case of clay soils that fail to drain not because of compaction but because of alkalinity, what is happening is that the sodium (i.e. alkaline) particles bind the clay particles together tightly by means of an electric charge. When you add gypsum, an actual chemical change takes place, breaking this charge. The calcium in the gypsum (CaSO4) has the opposite charge to the alkaline particles and attaches itself to the sodium in the clay, thus releasing the sodium. This results in opening up the soil structure so it becomes more granular and then it drains. One needs to add the gypsum every couple of years to keep the effect going. Otherwise it will revert to the way it was.
Thanks for the blessings.
Thanks so much for your response! I first noticed this problem in early summer–so it is definitely not the seasonal change. I will check the Ph–the soil here is typically on the acid side, but I may have given them too much oyster shell over the past several years. I will also check the drainage–everything is on berms or mounds, and the entire farm is on sloping hillside, so drainage is usual not a problem, even in our clay veins. I will check for the mites. With the winter/rainy season approaching, irrigation and fertilization will not be issues till spring–but perhaps I will give them my low-N mix: glacial rock dust, azomite, bonemeal, green sand, and kelp meal.
I like your web site very much, love your positive and encouraging attitude, and have recently tried one of your suggestions: using water soluble, OMNI-certified gypsum on certain plants that are in a clay-y vein of soil here, including some avocados and lilacs, some of which show minor signs of root rot. UC Davis also recommends treating root rot with gypsum (the calcium is the antidote) and heavy wood-chip mulching (presumably to absorb some of the water).
You say humic acid releases the minerals in clay. I bought some to make compost tea for trees. But would you recommend simply dilluting it alone and applying to the plants that are growing in the clay vein?
Well, thank you for your incredible generosity!
Blessings!
Thank you so much for the additional information–especially on the history of humic acid, your uses for it, and the results you have observed–I will definitely try it on my fall transplants (perennials and trees), and the established plants in the clay vein. (You do not mention any caveat about using it in fall or winter, so I assume it is OK to do so.)
I also appreciate your sharing the info re petroleum-based sulfuric acid being the objection to gypsum (the OMNI-certified brand that I am using is called Diamond, by the way). I find the USDA Organics web site very difficult to navigate, let alone to extract any useful information from, unfortunately. Do you perhaps know the low-down on green sand? From one local farm supply company, I heard it was no longer being certified, while another said they hadn’t heard that, and I noticed it is still being used in some OMNI-certified mixes. I can imagine that there may be heavy metals in it, given the state of rivers in America from which it is extracted. I have also heard from vendors that the organic rating does not in the least ensure an eco-friendly product–for instance, peat moss is certified, but the ecosystem is being obliterated by its extraction (Sadly, FSC-certification is no guarantee that forests are being protected either.)
What you say about the effects of gypsum is corroborated by a very informative web site: spectrumanalytical (.com, I believe, though it is affiliated with a university). I appreciate your encapsulation, however.
Many, many thanks–all very enlightening!
Greensand is glauconite, a natural greenish mineral mined from the ground, that has often been mixed with sand or clay. It mainly consists of potash or potassium (K), one of the world’s most abundant minerals and it also contains iron silicate and trace minerals. In farming and gardening greensand is used by organic gardeners and by farmers as a slow-acting source of potassium and has been used this way for centuries. It is mined in Texas, Arkansas, Florida and from large deposits in New Jersey. All these places were at one time under oceans which later dried out and the potassium collected together in veins which eventually sunk deep in the earth. For hundreds of years adding greensand to fields and gardens has been considered a good organic way to provide plants with potassium and/or iron. Sir Albert Howard, considered the father of organic gardening, wrote about it in his books, published in the 1920’s, 1930’s and early 1940’s. In my books I suggest Sul-Po-Mag as a source of potassium, because it’s easier for gardeners to find for sale, transport, measure, and use. However, some organic gardeners swear by greensand and it has been used for centuries to amend iron-deficient, alkaline soils. Is your soil iron-deficient? Clay soil usually contains plenty of iron, but sandy soil may lack iron and this is why we do need to fertilize with balanced fertilizers containing trace elements, or if not then apply seaweed, humic acid and such which are additional sources of trace elements. I cannot vouch for the purity or safety of the greensand available to you, but certainly the type from deep mines is an ancient mineral and comes straight from the ground and thus how could it be polluted by our modern rivers? The main problem about greensand is that it is heavy and thus costs a lot to transport and I think one needs to use a fairly large amount of it for it to make an appreciable difference.
Regarding fertilizing I have found through the years that it’s not necessary to be too technical about it. For example, simply manuring the ground once a year in fall, as long as the soil doesn’t become too alkaline, can do wonders for fertility. Many of our California soils have adequate potassium and phosphorus, which doesn’t mean we shouldn’t add some but what our dry-climate soils really lack is organic matter. By building that up with homemade compost and manures we can improve soil by light years from what it was when we first came upon it.
I actually made a technical mistake last night when I explained the action of gypsum on clay. A chemical exchange takes place and I think I said (incorrectly) that the calcium “attaches itself to the the sodium in the clay”. That was not what I meant to say. What I meant to say was that some of the calcium in the gypsum combines with some of the clay particles in an actual chemical exchange that results in releasing the sodium. The loosened sodium can then be washed away by rains or irrigation and this opens up the soil. The main reason for understanding these sorts of things is simply that it makes gardening more interesting and also it convinces us by giving reasons why good practices are wise to undertake. This understanding makes it impossible to forget to add the gypsum in the bottom of the planting hole when the hole was dug into hard clay soil. At least for me that’s the way it works! I don’t like doing things without knowing the reason for the action.
Thanks so much for the info on greensand. I got hooked on it when my large indoor potted plants showed signs of potassium deficiency and recovered after the application and have never shown those problems since over several years. I like the fact that it breaks down so slowly, as well. The kind I am currently using is a New Jersey brand, and I had once read (on some packaging, as I recall) that it was dredged from rivers–I am relieved it is not.
I just started using chicken manure on certain trees last spring, and they responded so wonderfully well, that I decided I would apply it to all of them this spring–and just as you say, leave it at that (no more fussing over trace minerals and such). Rodale states that NP&K are all released from the manure. McEvoy–the organic olive producers (80 acres in Petaluma–we mill our olives at their Community Milling Days) recommend a mix of manure, dolomite, and kelp meal. We plan to have chickens at some point, so we will not have to import the manure one of these days.
You say to apply it in the fall… I had wondered about a fall application, and these were/are my thoughts: Since N travels, especially in the heavy rains, won’t it wash away in a fall application before it does any good? Also, will the N be released so quickly as to stimulate growth at the wrong time, when they should be hardening off? Since Rodale seems to always recommend late winter/early spring applications of manure and fertilizers (especially with apple trees: no fertilizer after June 1), I just thought that was the best time to do it.
I had the same thoughts about alfalfa mulch–Rodale recommends it for Apple trees, among others, and says it will break down over a period of years, but will it be releasing N at the wrong time of year? When should it be first applied?
I also just assumed that our top soils have been hugely depleted and polluted by deforestation, salmon fishery depletion (all that Nitrogen and Calcium that the fish left after massive spawning that fed the forests is no longer happening), and conventional farming for so many decades that it must be depleted. So, as long as I could afford it, I thought I would add nutrients.
As far as compost goes, we have been adherents from Day One, since it is Rodale’s mantra, and I made my first vegetable garden using the first edition of that book in West Hollywood when I was 14 years old! Now we add 50% compost to the native soil for every berm, hole, or raised bed we create. Sometimes for the worst clay veins, we import soil and work it into the surrounding clay. as well as the 4x4x4 hole we put the tree into. We also top dress everything annually with many inches of compost, and we add additional organic matter with green cover crops, such as sweet clover and legumes (though we do not till these in–we cut them at the roots. Many inches of mulch go over the compost top dressing. Any other ideas along these lines would be much appreciated.
It is so wonderful to be having this dialogue with you. Very hard to find mentors who understand the big picture, especially as we move away from the destructive practices of conventional farming into relatively new practices like permaculture, carbon sequestering, and large-scale water management, and new technologies, such as the uses of gypsum and humic acid. So much partial or misinformation out there.
So many thanks!!!
Thanks for the information on the good and lasting effects of greensand on your houseplants. Chicken manure is sort of a miracle food I think. After coming to American, my mother bought a farm in Pennsylvania and turned it into a chicken farm. I spent very formative years from age 11 through 15 there. My parents were early organic gardeners, followers of Rodale and Sir Albert Howard, whose books they had read while still in England. We spread chicken manure on all our fields and everything grew like mad. Once at a garden writers convention I sat at a table with 5 other garden writers and we learned we had all grown up on chicken farms. It just makes one think one has a green thumb. Another connection with you is that after the farm we moved west and I went to Hollywood High School in the 1940’s. Please also note the 2-Part article I wrote on composting published by the San Diego Reader.
You bring up a good point about chicken manure better applied in spring. I agree and in my organic book I suggest the times to apply for various crops. When I tell people to spread manure in fall I am usually referring to clean (non-salty) horse manure. I tell people not to age it in a pile at that time of year but just put it on top of the ground and let the rains wash the goodness into the soil.
Regarding deciduous fruit trees, light applications of fertilizer are all they need and in Mediterranean climates this should be applied in spring (not fall) just as flower buds swell. Chicken manure would be fine at that time.
A wonderful nitrogen-rich compost can be made by layering alfalfa with horse manure and letting it age 3 months. This can be added on top of the ground any time or combined with the soil prior to planting. Alfalfa mulch is great to use any time, also, since not enough nitrogen would be released to make a difference but over the long haul surface roots will be fed and a very fertile soil will gradually be created. Some nitrogen will be lost into the air when used as mulch but not so much as to make it a negative factor. Alfalfa meal makes a good fertilizer to wash into the ground or make alfalfa tea with. (All these subjects are discussed in detail in my book, “Pat Welsh’s Southern California Organic Gardening: Month-by-Month,” published by Chronicle Books, 2010.)
Mrs. McEvoy who founded the olive grove you frequent is the mother of Nion McEvoy, the owner of Chronicle Books, who believed in and published my first book over 20 years ago and still publishes this book in its up-graded all-organic edition today.
It sounds as if you are doing an amazing job building up the organic content of your soil. I can’t think right now of any suggestion of how to do better, other than various comments I worked in above and the idea of putting a layer of horse manure in fall all over any soil you wish to improve, over the roots of roses, for example, or whatever. You can dig it in in spring. (But if you do this be sure your tetanus shot is up to date.) Green manures are also a great way to improve soil. I wish I could do as well as you are doing but I am physically past it now and into easy care. I can do little gardening myself any more. Being thrown from horseback is what caused my physical limitations, not gardening!
Regarding carbon sequestering this is a fascinating subject and recent discoveries of ancient man-made soils in the Amazon basin give us much to consider. Charcoal is the accepted method but until further studies are done I don’t recommend this for our Western soils because of the problem with alkalinity. Charcoal application has also been used to clean up polluted soils.
Thank you for your wonderful missive, and the personal tidbits about you. I feel honored. Shortly after visiting your web site, I ordered your book. When it arrives, I know I will so enjoy reading it from cover to cover. I am delighted over the serendipitous connections, like with the McEvoys, as well!
I am so very sorry to hear of your riding accident that left you physically compromised, and especially after having been obviously very active out of doors! That must be hard. One consolation is the many people you have helped through your blog that perhaps you would not have had time to help, had you been gardening. I know the latter typically takes all my time from sunrise to sunset.
My partner recently read your article on compost, by the way. We have been wanting to make our own (we import OMRI-certified from local vendors, 15 yards at a time). We have a lot of weed piles, but were stymied by the problem of finding a recommended, affordable, safe, and effective chopper/shredder machine. Your solution to just machete it was a good one that we intend to try. Though I saw a hand-crank shredder recently–in the great permaculturist Geoff Lawton’s video on soils–that intrigued me.
I went to Bancroft Junior High while my sister went to Hollywood High. But after that year, my mother was disillusioned with the public school system (as were we, despite making great lifelong friends at both institutions) and we were sent to an “experimental” high school in the San Fernando Valley based on the principles of Summerhill and other innovative education experiments–this was the late sixties–the heyday of hope, progress, and experimentation on a societal level.
It sounds like your parents were innovators too, open to what must have been at the time the radical ideas of Albert Howard and Rodale. I also think you were blessed with that early farming experience that helped establish your amazing connection with growing things at an early age!
I am so glad you strongly corroborate my nascent impressions of chicken manure! The reason I tried it is that I noticed after cleaning out one of our barn owl nesting boxes, the ground cover in the area under it, where all the waste had fallen, grew at least five times as big and a deeper, richer green than anywhere else in the field. I went on a mission to see what I could get that was kin to barn owl manure. I ended up trying bat guano and chicken manure, the latter being easier to apply, the best results, and cheaper to boot!
Thank you so much for the tips on the horse manure and alfalfa, when to apply, etc. You mention the horse manure must be “clean” (salt-free)–how do you ascertain that? We have many stables in this rural part of West Sonoma County who give away horse manure if you pick it up. We made a compost out of manure and rice straw the first year after we bought the land, but have not done it since. This is because I had heard from several sources that horse was not the best choice in manures. However, I see it can be boosted with alfalfa, and that another useful property is that it can be applied year-round. My tetanus shot still has another 3–4 years to go! Thanks for the concern!
Here’s one for you: Have you heard about the University of OR study of coffee grounds–supposedly as rich in N and effective as cow manure, without the pathogens? We have started getting organic grounds from a local cafe to see for ourselves.
I have read a couple of articles about the charcoal-making of older civilzations. I want to understand it better and read more. There is another Aussie permaculturist who does deep, thin-lined plowing of pasture land on a very large scale, innoculating the soil 2.5 feet deep with good bacteria and fungi, which he says, if done on a vast scale, will counteract global warming by absorbing CO2. Not totally sure how this works, even though I have viewed seven of his 21 or so videos on the subject! My guess is that ground-cover roots can grow deeper and better with the innoculant applied that deeply, and therefore absorb and sequester more carbon (???)… Any thoughts?
Well, my dear, off to the food forest!
A cyber-hug for all your great help!!!!
You are certainly a devoted organic gardener. Thank you for this informative email including many facts of help to other organic gardeners, and thanks for ordering my book!
A few quick answers to your queries: You asked how to find salt-free horse manure. Of course, there will always be some salt in any manure or urine of humans or animals. But what I meant was manure that is largely free of salt from salt licks. My experience is that good horse owners “muck out” their stables and corrals daily. That is, every day they go around with a pitch fork and wheelbarrow and scoop up all manure. This is the sort of horse owner or stable you want to find. Don’t get the manure from a messy, badly kept barnyard or corral. One reason sheep manure and goat manure are fine to use is because this is usually clean manure simply because of the way the animals are kept, usually on pasture. And by the way, I’m sure you know not to used pig manure because it contains dangerous pathogens. We didn’t know that on our farm in Pennsylvania. Nonetheless, we used it on the fields not on the vegetables, simply because of the smell.
Mares drop their manure wherever, but stallions and pride-cut geldings stack it neatly in a corner. When a horse owner or stable owner doesn’t care, the animals begin not to care either and kick the manure around and bits of salt may get into it and lots of bedding may get mixed into it too. The same thing happens when steer, cows, and other cattle are kept in a feed lot. It’s a horrendous situation and usually there are chunks of salt getting mixed into steer manure, and sometimes you can see it in dry bagged manure.
When getting horse manure, it’s okay to include the bedding (sawdust or straw) and to include it also when spreading manure like mulch on top of the ground, since the sawdust particularly contains the urine which is a strong source of nitrogen, it’s good to use, but then one cannot combine it with the garden soil without letting it age because it won’t be fully rotted. This, in my opinion, is why we are told to age manures in manure piles, when actually it’s fine to spread it fresh and let rain wash the goodness into the ground. The reason for the aging caveat is that folks might dig fresh manure into the ground and that is a no-no for several reasons: Fresh manure can burn roots and un-rotted bedding will subtract nitrogen from the soil in order to rot. But an Extension Advisor in Ohio wrote an article that I once came across on the Internet that agreed with me. His point was why should we waste all that good nitrogen pouring down into the ground under a manure pile for three months and incidentally causing runoff into the ground water, when you could have been aging it along on top of the ground surrounding plants so that the nitrogen, which he pointed out mainly came from urine, could be going down into the ground to feed plants, not just to be wasted while actually harming the environment.
Thank you for mentioning the Oregon University study on coffee grounds http://extension.oregonstate.edu/gardening/node/1009
. I had not heard of but at my talks recently several folks have asked about them. I usually suggest using them and tea leaves also on acid-loving plants, now I know since reading this article that they are not acid, but neutral. Also, they are not a source of nitrogen, nor are they fully rotted, of course, so it’s best not to dig them into the ground unless you add plenty of nitrogen. The article suggests using them as a nitrogenous waste in the compost pile but they cannot be considered a nitrogen fertilizer.
Regarding sequestering CO2, I find it a little difficult to understand also, since after all none of these methods allow one to grab carbon dioxide or methane from the atmosphere and stick it into the ground. The only good it does as far as I can see is to prevent a current or future source of carbon dioxide from escaping into the atmosphere, such as the methane in coffee grounds, for example, which would be released from a dump if they go to a dump.
Regarding rhizobia and inoculants in soil and for plant health, I am totally convinced of their benefits. Deep plowing, however, is today a controversial subject. Some experts believe in such practices as double digging and deep plowing. Others believe in shallow plowing or even no digging at all. Many experts now feel it is unwise to disturb the natural mechanisms that exist in the ground which can create a web of beneficial bacteria, rhizobia, fungi, and other organisms out of sight in the soil and that one should not disturb the soil horizons either. I believe that the lasanga or Ruth Stout no dig method of gardening is a perfectly workable system, but that it works better in a wet climate than a dry one, which does not mean it can’t be done. In fact, I have included basic instructions in the latest edition of my book, the one you are getting. But basically I am still of the old school that digs up or plows the ground and adds organic amendments of various types to enrich the soil. Also, European earthworms are most likely not a good thing out in nature where they destroy leaf cover, but fine on farms and in gardens where they help to combine organics with the soil. They are especially helpful in sandy soils.