We were at 8 weeks on our black bean plants beautifully making their way up the trellis, when we decided to treat the leaves with Neem oil spray. A number of holes had appeared in the leaves which we presumed to be the result of aphids. We applied the Neem spray at 6pm. Instructions on the bottle asked the user to spray so that leave was saturated, and that to be effective, entire plants needed to be sprayed. The following days, the lower leaves turned yellow and began falling off. Tested soil: pH of 7.8 (slightly alkaline), and moisture meter (which shows indications of dry, moist, and wet) has the needle pointing halfway between moist and wet. I'm thinking that the runoff of the neem oil in the soil causes inability of root system to take up iron, or nitrogen, or both. Going to add 2 teaspoons of vinegar to gallon of water for next watering, and going to spread coffee grounds to add some nitrogen to soil. Any other ideas would be greatly appreciated as it is disappointing to see the plants suffer this late in the season.

Image by: Clare_CAMichelia AlbaWhich Shrubs Smell Good? -   Michelia Culture         The following guidelines on Michelia culture were provided by Fredrik Liljeblad in a post to the Fragrant Plants Forum in July 2003.   I wrote this article on Michelias earlier this year.  In it, I go into considerable detail about their culture. FYI: the cultural advice is based on my Coastal San Diego, CA, climate, so you may have to adapt accordingly. I am a great believer in keeping Michelias in large containers, because:   1. They can be moved about in the garden to find the ideal spot 2. Established Michelias resent being moved and suffer setbacks when they are moved 3. Water, soil, and feeding can be more easily controlled 4. If an unexpected frost is due, they can be moved temporarily into outbuildings or under overhanging eaves   My 12' M. alba is in a 20-gallon container and doing very well. If you're potting up, count on the plant spending about 5 years in the same container. To avoid root rot, make sure drainage is excellent--not just good, and mix a handful or two of activated aquarium charcoal into the potting mix to keep soil that the roots haven't yet reached from getting sour; drill extra drainage holes if necessary. If you live in an area with alkaline water (as I do), flush the mineral salts out of the container about every other month (see article). Putting about 2" of pea gravel into the bottom of the container helps drainage and also stabilizes the container in high winds (which Michelias dislike anyway).   My strongest advice is to (at least initially) grow most Michelias in containers for the reasons stated above. M. figo is an exception, but it still needs to be given proper culture and its hardiness limits (see Sunset Western Gardening Book) need to be respected if it's in the ground.   Here's the article:   Haunting Scents of Paradise-The Unforgettable Michelias By Fredrik Liljeblad   If I were exiled to a barren island and allowed to take only one fragrant plant with me, it would be my Michelia alba. With difficulty-perhaps even a tear or two-I'd say good-bye to my collection of gardenias, and I'd sigh as I took a parting sniff of my Chinese jasmine (Jasminum polyanthum), whose trusses of pinkish white flowers permeate every inch of my garden and house with their heady scent each February and March, but my precious Michelia alba, now a 12-foot tall tree, is the one fragrant plant I could never part from.   Michelias are a family of sub-tropical bushes or small trees related to magnolias that produce relatively small but powerfully fragrant flowers. The unique perfume, pungent and fruity, has been likened it to a range of fruits: bananas, pears, apples-even mangoes! The base for "the world's most expensive perfume," Joy, is the essential oil extracted from Michelia alba, commonly known as the "white jade magnolia" or "white champaca"-more on this confusing terminology later on.   My own first encounter with Michelia alba was during Chinese New Year in Taipei in the early 1980s. A Taiwanese friend and his family took me to the Lung Ching Temple in the oldest part of the city on New Year's Day. There we bought teardrop-shaped, waxy-looking ivory flowers with the most incredible perfume I'd ever smelled. Each had a small thread looped through the short stem for hanging on wire racks next to the altar. My friend explained that the scent was so wonderful, it would "rise up to Heaven and get the gods' attention" as we asked them for good fortune in the coming year.   Later, when I lived in Thailand, I'd get up at dawn for my morning walks and buy several bags of Michelia alba buds ("chom-pii" in Thai) from the flower garland sellers outside the Erawan Shrine in Bangkok. When I got back home, I'd float them in bowls so the scent permeated every room in the house. In Java, where M. alba is known as "cempaka putih," the flowers are ritually offered at temple ceremonies to mark holidays, births, or deaths.   After moving to San Diego about 10 years ago, I found myself missing the scent of michelia flowers. As a surrogate, I bought a related variety, M. figo (aka M. falcata), commonly called "banana shrub," on a visit to Tropicworld. As lovely as the fruity scent was while it floated through the house on the warm breezes of March or April, it couldn't replace the almost painfully intense and complex perfume of Michelia alba.   On my trips to an Asian supermarket in KearnyMesa, I would sigh over the $100-plus specimens of M. alba, the costliest of all michelias, on display in the nursery area. Finally, I ran across a specimen at Walter Andersen's. It was mixed in with a group of M. champaca (less expensive than M. Alba), and had been accidentally priced the same as those. When I pointed this out, they insisted on selling it to me as marked (this isn't the only reason Andersen's is my favorite nursery, but it didn't hurt). What a thrill! Today that same tree, now over 12 feet tall and bearing more than 300 flowers each year, grows in an outdoor seating area in my garden where I can enjoy the heady fragrance over morning coffee or during an after-dinner chat with friends.   There are quite a few members of the michelia family, but in American nurseries we commonly find only four, two somewhat hardy varieties: M. doltsopa and M. figo; and two rather tender ones, M. champaca, and M. alba.  All michelias have handsome foliage-sturdy, somewhat waxy, pointed leaves that vary from a light grass green to a medium green. In the hardier varieties, the leaves are held fairly stiffly in the manner of their magnolia "cousins." In the tender ones, the leaves are larger, resembling those of avocados in shape and growth habit, but have far more substance and a lighter, fresher color. They are also very fragrant when crushed, reminiscent of lemon verbena. The flowers of michelias vary slightly in color, and tend to be smallish, long and pointed. In form, they bear a slight resemblance to Magnolia stellata when open, but with a waxy, substantial texture.  M. doltsopa, which comes from the foothills of the Himalayas, becomes a huge tree in its native habitat. Even in California, it's been known to surpass 40 feet. We in San Diego have a specimen at the zoo, and there is also one at the Huntington. M. doltsopa's flowers are fairly large, but are probably the least fragrant of all the michelias. It is a beautiful tree nonetheless.   Michelia figo, the Banana Shrub, can grow to a 15 foot tree, but is usually below 8 feet. Of all the michelias, it has the handsomest branch structure and lends itself to "oriental" effects. The heaviest bloom tends to come in March-April, but some flowers appear throughout the warmer months. The 1-2-inch flowers start as fuzzy, tobacco brown buds, and are a pale banana yellow with knifeblade-thin maroon borders on the petal edges. The plant is appropriately named-the blooms are strongly redolent of banana with a slight apple overtone. There is a U.S. hybrid, M. figo 'Portwine,' whose slightly smaller flowers are entirely maroon.   Of the two rather tender michelias in U.S. commerce, M. champaca, and M. alba, M. champaca is slightly less tender and grows slightly taller than M. alba. It has saffron to pale daylily orange blossoms that are somewhat less fragrant than M. alba, but quite fragrant nonetheless.   As I've mentioned, M. alba is the most powerfully fragrant of all the michelias, with a scent that reverses the proportion of banana to apple found in M. figo, and adds an indefinable "tropical" note as well. It is a handsome tree, somewhat less "architectural" than M. figo, but making up for it in size, profusion of bloom, and length of bloom season. The approx. two-inch long flower buds need some warmth to mature and open, but in practical terms for coastal/coastal strip San Diego gardeners, this means a bloom season that lasts from late March through at least early November or sometimes January, with slightly less production during the May grey/June gloom. Buds, once formed, persist until ready to open, and bud drop is rare.   Despite covering a wide swathe of sub-tropical and tropical Asia, michelias are quite uniform-with the exception of cold tolerance-in their cultural requirements. Some, however, are more unyielding than others. The fact that michelias are related to magnolias is an indicator of their nature: these are surface-rooted, acid-loving, second-story plants that want warmth and a lot of light, but limited direct sun.   Michelia's light requirements are somewhat complex: as much as they like lots of light and warmth, full sun-even at the coast-dries out their leaves and turns them an unpleasant yellowish green. The ideal situation is direct morning sun followed by light dappled shade under high trees. This can translate into any one or a combination of these scenarios: light all-day shade; full sun until late morning with part shade the remainder of the day inland; full sun until early afternoon, then part-shade the rest of the day near the coast. Strong afternoon sun in summer-even at the coast, is not a good situation for michelias.   Michelias also dislike windy locations. Although my garden is near-coastal, it's not at the coast, so the daily prevailing ocean breeze begins about 2:00 p.m. Initially, it took some experimentation on my part to find the proper spot. Until I did, my M. alba was getting rather leathery, netted leaves from the combination of sun and wind. When I moved it under the high, overhanging branches of a White Chinese Mulberry, it perked up enormously. It now gets light all day but little direct sun, and the mulberry also helps baffle the daily ocean breezes-with additional help from my house and a large, vine-covered trellis.   Like magnolias and camellias, michelias have a shallow root system with lots of fine brittle roots. This means that michelias, except perhaps M. doltsopa, are quite amenable to container culture and, in fact, dislike root disturbance as there's some inevitable damage to the brittle roots. At least until you've found the perfect location, I favor keeping michelias in containers since it enables you to move them about the garden. The potting mix I personally like is leafmold, osmunda fiber (orchid mix is OK), perlite, azalea/camellia-type potting soil, composted pine needles, and horticultural coconut coir (coir poses far less danger from overwatering than water-retentive peat moss).   Mulch michelias with leafmold mixed with their own dropped leaves (michelias shed some leaves all year long, but especially in the spring when the new leaves emerge). In watering terms, you can't go wrong if you mimic camellia culture, keeping in mind that michelias' foliage is not as stiff and transpiration resistant. I personally water somewhat lavishly since the above mix drains so well, but if in doubt, root rot is a greater danger-especially during the winter months and the May grey/June gloom periods. On the other hand, all michelias, particularly M. alba and M. champaca, like even more humidity than camellias. Spray or mist the foliage in early morning, and several times a day during a Santa Ana.   Also, because our water here has so much mineral salts, I use drip irrigation for 12 hours once a month to leach out all the salts. Without leaching, you run the risk of some marginal leaf burn.   Unlike camellias, michelias are greedy feeders. I give mine a varied diet: the basis is usually Safer brand liquid plant food for Azaleas, Rhododendrons, and Camellias, but MiracleGro for acid-loving plants works almost as well if you leach. I start in the spring with Peter's 20-20-20. From May to October, I alternate acid-loving plant food with Superbloom to encourage flower production. Because our local water is so alkaline, I also give a dose of Safer's IronPlus 5% about four to six times a year, usually right after leaching. If the leaves start to look a yellowish green (they're never much darker than a light grass or apple green anyway), I may give a 1/2-strength foliar feeding of iron in between regular doses. I usually don't fertilize from late October/early November until the end of February, just in case we actually do approach a freeze.   You will notice that michelia buds usually form among the leaves rather than at the tips of the branches. Especially as they get ready to open, they become very brittle and snap off easily, so be careful when touching the tree. Unlike camellias, michelias seldom drop buds unless the plants are very stressed. If underfed, however, bud production will decrease considerably. Buds on M. champaca and M. alba will often just sit there waiting for warmer weather, so don't be alarmed. Michelias can hold on to their unopened buds for a long time before they open. Incidentally, if you're in a dry area, try to mist the air frequently during the hottest part of the day. Michelias like warmth, but they also like some humidity.   With the exception of M. figo, most michelias tend to produce very vertical growth. If you're buying a M. alba or M. champaca, try to choose one that displays at least some tendency to produce horizontal growth. Pruning is not the answer, but rigorous tip-pinching of the uppermost leaves will force side growth. One problem many michelia owners encounter is distinguishing the leaf buds from the flower buds in the early stages. There's no substitute for carefully observing your plant, but here are some things to watch for: flower buds maintain their bulletlike shape; leaf buds, past a certain point, develop pointy "tails" reminiscent of green beans, but with a slight twist to them. A bud at the very end of a branch tends to be a leaf bud, as most flower buds emerge from existing leaf axils.   Despite all the above, michelias are not difficult to grow here, they just require an understanding of their needs. Given that, they will reward you with that haunting scent for most of each year.   Some good local [i.e., San Diego, CA] sources for michelias are Walter Andersen's, Pacific Tree Farms, and Mission Hills Nursery.  

I think so- it will take a few applications to kill the eggs and all. Also, I just read that lowering the temperature, even just at night, as well as having good air circulation will help keep the spider mites away. If you happen to see scale reappear, you can treat them with a q-tip and rubbing alcohol, but your current infestation is too dense and needs the neem oil. There are several other recent posts on here with the same issues (and pictures too!)- read through them and see if you can find more information that might be helpful to you :)

@Embothrium "Pictures above show too small clay pots filled with coarse soil less potting medium. This combination will guarantee chronic problems with quick drying out and with recurring nutrient deficiencies." that's how I grow my michelia alba as well. I use 511 mix in small clay pot. it does save my plant from root rot. however, it has serious iron deficiency. I wonder if I should fertilize it often or even use iron suphate. my m.alba did had root rot twice and had been repoted 3 to 4 times within a few months. the iron deficiency maybe related to stress as well.