Blueberry Problems

We had a lovely crop of blueberries this year, and in fact some of the bushes are still producing. However, Tom and I noticed that something was going very, very wrong on one of the plants. The leaves were looking like this:

First, only one plant was affected, and I went ahead and cut it to the ground, fearing a disease or infection. However soon an adjacent bush began showing the same symptoms. Then I got worried. I wracked my brain for blueberry information. I did a lot of online research. And I still couldn’t figure it out. So, I wrote to our local branch of the Master Gardeners (here, affiliated with the University of California system) and sent them a picture. The MG’s have a vast library with lots of resources and lots of experts with whom to consult. I wasn’t sure I’d get an answer, but yesterday I received a very excellent reply which totally blew me away. Here it is:

“Hello Elizabeth,

Thank you for contacting the UC Master Gardener Program Help Desk and for sending us photos.  It sounds as though the management of your blueberries has worked well in the past, and has not changed recently.  I understand you lost a blueberry bush to a similar-appearing ailment, and now a second bush is affected. It does not look like a virus, and most likely is a fixable problem.  There is one less likely but potentially serious problem I will also address.

The pattern on your leaves is called marginal necrosis.  The simplest problem causing this is inadequate water.   Drip systems can clog up over time, and our weather has been very hot recently, causing more water loss than usual.  Gently dig down several inches into the adjacent soil and make sure it is moist.  If the organic component to the soil has broken down over the years, it may be draining too fast.  You are an experienced gardener and may have checked this already.  If the drip system is not working, I would try unclogging the outflows or replacing the tubing.

I discussed your problem with one of our “blueberry expert” Master Gardeners.  He also had a good crop this year, yet his leaves are showing a similar pattern to yours.  He thinks the most likely problem is either a watering issue, or a problem with the soil, which I will discuss below.  Also, has the afternoon shade increased too much, due to tree growth?  Blueberries are finicky and this might affect the leaves too.

There are several potential issues with the soil.  Marginal necrosis can be caused by high soil salinity, high chloride, high boron content, magnesium deficiency, or potassium deficiency. Typically, the older leaves are more affected.  Also, there is general agreement among us that even though you had a good crop, the soil may not be acidic enough.  As you probably know, the pH needs to be 4.5 - 5.5, and is very hard to maintain for plants in the ground.  Typically you need to acidify the soil at least annually.  All these factors can be checked with lab-based soil testing (see pdf link).  This will provide lots of good information and is well worth the price.

The less likely but most serious problem to be addressed is whether or not this is a fungal infection, such as verticillium wilt.  This is suspicious because you lost one plant with a similar condition, although blueberries tend to be resistant to pests and diseases.  This disease comes up through the soil, gets into the canes, and then spreads to the leaves.  Typically one or a few shoots will be affected first, often the younger ones, unlike with soil chemical problems.  If you cut through one of the canes with affected leaves and look at the cross-section, you may see browning or blackening of the water conducting system of the plant (the xylem).  This fungus lives in the soil, is easily transported through water splashes or contaminated tools or shoes.  

There are no sprays available that will kill this fungus.  Make sure you completely remove the other affected plant, including the roots.  I do not think you need to get rid of this current plant until we know for sure what this is.  In the meantime, do not cross-contaminate your other plants – wash your hands and shoes well, and disinfect your tools using a 10% bleach solution.  Soil solarization (clear plastic over the adjacent soil) may reduce the quantity of fungus, and that’s something cheap and easy you could do now with little harm done.  A cutting could be sent to a lab for diagnosis; I will include a link below.

Finally, has a neighbor been using herbicides, such as Round-Up, near your plants?  These can get carried on the wind and damage nearby plants, causing marginal necrosis.

Marginal necrosis

http://ipm.ucanr.edu/PMG/GARDEN/ENVIRON/marglfnecrosis.html

Tobacco Mosaic Virus

http://ipm.ucanr.edu/PMG/GARDEN/VEGES/DISEASES/tobaccomosvir.html

Soil testing labs – see attached pdf file 

Verticillium Wilt

http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/vertwilt.html

Plant testing lab

https://www.cdfa.ca.gov/plant/ppd/plantpath.html

Please contact us again if you have further concerns or questions.”

Isn’t that something? I was amazed.

So, today, Tom and I did our due diligence and performed inspections. We had forgotten that I had cleared a huge patch of parsley out, which had been next to these two affected plants. When I did that, I moved the irrigation line closer to the blueberries. Inadvertently, it turns out I had turned it off at the same time. DOH! Then, when we ran the drip system, another low sprinkler was in a place where it was covered in leaves, so the water was just dripping right below it instead of spreading out over the whole blueberry patch. So, with those two irrigation lines running correctly again, I’m hoping that solves the problem. We also discussed the fact that we had pruned a large branch off the tree above the blueberries about a month ago. Both removing that, and removing the parsley, had allowed more direct sun on the bushes, as well as allowed more evaporation around the bushes. With that plus the water deficiencies, the bushes were unable to keep the old leaves healthy and green, so the plant sacrificed them.

I also noticed that the soil below the bushes was hard, compact, and dry. Regular water should fix that up, but I also did as the MG’s suggested and added an acid fertilizer and watered it in. In the fall, when we spread compost everywhere, I’ll be sure to add several inches to this area so that the blueberries have better water retention.

So there you have it! Another reliable resource to contact if you have any burning questions not answered by your own knowledge or research. I’m so grateful to the MG’s for answering my question so thoroughly. They are all volunteers and I’m just amazed at this service!

Now I’m casting a more critical eye on other areas of my garden that have been looking peaked lately, and wondering if the drip is working in those areas. Tom and I check the veg beds every year, but we often just assume everything is working right elsewhere unless we see a problem. I think we’ve learned a lesson here, that we need to be more thorough.

Sunburn

Over the weekend, I asked Tom to build me a sort of shade covering for the peppers. This is what he came up with and I love it. The covering is agribon, the same stuff we use to protect from frost in winter. I didn’t want the peppers to be totally enclosed, I just needed a little light protection from the intense sun in the heat of the day. This is because my peppers are suffering (and suffer every year) from sunburn.

That whitish spot at the top of the fruit is the sunburn. It’s not the worst thing in the world; the rest of the pepper ripens normally and can be used, cutting away the damaged area. But it is a real nuisance when every single one of your peppers has it. It seems to affect the bells worse than the corno di torno types, but even those get it sometimes. And here’s the thing - peppers are sun lovers! Sun worshippers! They need heat and sun to be at their beautiful best. But in our area it’s a little different, and here’s my theory about that. As you can see from the picture up top, our pepper plants never really develop that full, leafy, luscious green look that plants in other parts of the country get. It’s because of how dry it is. I have drip irrigation on these plants as I do all of my garden, and while that keeps them alive and producing, it’s not enough to produce the kind of lush vegetation that would protect the developing fruit from the direct rays of the sun. As far as I know, sunlight on the actual fruit has no affect on ripening or sweetening - it all comes from the effect of the sun on the leaves. But the plant has to protect itself from dryness somehow, and it won’t sacrifice fruit because that’s how it reproduces. So what can it sacrifice? Some of the leaves. Hence, my plants are puny but still produce a good amount of fruit.

This is just a theory. You can help me by letting me know if you live in a rainy part of the country and grow peppers. How do your plants look?

Anyway, I’m hoping the light shade cover will take care of the sunburn issue. I get it on my tomatoes, too, but it’s impossible to provide any kind of shade cover at the moment because the trellises are too big. Maybe that’s a project for next year. Shade cloth every summer over this end of the garden?

Tom has also built me a stand for my dehydrator (in full use in summertime), which keeps it out of the way but convenient. He’s become quite a dab hand at these projects, and I’m so grateful!

A nerdy side note: Do you know what your state rock is? If not, you can look here.

Our state rock is Serpentine (or Serpentinite). You can find this all across the state and is a beautiful greenish color. It is formed from igneous processes, that is, volcanic, and then is metamorphosed. I was hiking in Sunol Regional Wilderness yesterday, and once I got up into the hills, there was lots of this stuff lying around, as well as degraded sheets of it on rock faces, which is basically asbestos. Asbestos is formed as the rock weathers and erodes. The dust, of course, can be quite dangerous, but I think the rock is really lovely. There are whole plant communities that thrive on this sort of substrate, a very specific list, which is helpful to know if you live in a place with a lot of serpentine. How will you know this? You need to look at the geologic map of your property. (I wrote a post about this in the Spring of 2019.) You might enjoy finding out your own state rock and how to identify it while you’re out hiking!

Kitchen Days

These are the kitchen days - days where we turn on the fan, heat up the oven, get out the food processor, the canning rig, the jam pot, the pickling salt.

Every extra moment filled with processing and cooking. Tomatoes into puree, salsa, paste. Peppers roasted and into the freezer.

Basil blended with garlic, walnuts, salt, parmesan, and olive oil. Pesto in little jars, into the freezer.

Cucumbers, picked when small, fermented into half-sour dills, or sliced and canned for bread n’ butter pickles.

Warm squishy berries picked in the hot sun, then cooked down with sugar into jam.

It’s hot work, and it’s persistent work. But our winter selves will thank us for doing it. Our stores are filling up! And tomorrow there will be more to pick….

July Arrangement

July has to be sunflowers, right? They look at their absolute best during the early, very warm days of summer. I grow them in all sizes and colors, usually starting them from seed in the greenhouse, and planting them out in May.

Strawberry Blonde

But, cutting these incredibly large (7-8 foot, in some cases) plants and bringing them inside makes me sad, when the bees and birds like them so much. I really prefer to leave them in place to help the wildlife, plus their sheer size makes such a statement in the garden, that I enjoy them far more outside in the ‘wild.’

Music Box

And during this bouquet experiment, I am also realizing that huge, overblown bouquets don’t really work in our tiny, crowded cottage. The scale is off, somehow. And even one largish bouquet looks kind of like a polka-dot in the middle of our dining room table. I am much preferring small, untidy mixtures. For something like a dinner party, a lot of small mixtures looks nice together, and the scale is right for our home (not that we’re having any kind of party at the moment, so it’s a moot point). But for everyday, I am totally enjoying a little swing-cap bottle, maybe nine inches tall, on the kitchen counter by the sink, in the sun that comes in the window.

Sundancer

This little vase is completely unobtrusive, occupies a niche that nothing else does, stays nicely out of the way when counter space is needed, and cheers up the entire space. When the sun hits the flowers, they glow. I’ve had such a good time keeping this vase filled. Sometimes it holds some yarrow that accidentally broke off while deadheading. Sometimes it holds a small spray of salvia or penstemon. Right now it’s holding some small border sunflowers that started to sway dangerously sideways in a container.

Chocolate Cherry

I have realized that I honestly prefer to keep the flowers outside, where their enjoyment is a hundred-fold; not only do we appreciate their beauty, but so do the neighbors, and the insects, and the birds. Our house is made of windows, and we really get to look out onto a bouquet, of sorts, when we look out into the garden. This is something I planned for. Long ago, I read that a gardener should begin with the view from their windows. Why put a flower garden far away where you can’t see it? So I work hard to provide interesting views from every angle of our home. Adam has a view of a canna lily patch, bordered by rose of sharon and an oak leaf hydrangea, under the mock orange tree - a group of flowers given to him by a special friend. Rin has a garden cart outside her window (made by my dad) that is in the shade of our porch, and it houses several tuberous begonias and an Iresine brilliantissima, whose bright pink leaves light up the shade. Our bedroom window looks out over a Vitex agnus-castus, which I’m hoping will grow much larger and allow for some privacy, and into the herb bed. Our back screen door opens near our native huckleberry bush, which the house finches have found this year, and we enjoy watching them eating the berries. The kitchen window looks over our water feature, where birds and bees come to bathe and drink. I could go on forever about this, but you get the idea. It’s great to make your house, especially if it is small, feel like just a part of the larger landscape.

On the flip side, I’ve also heard that having flowers in the house makes folks feel good, too - sort of wealthy, in beauty if in nothing else. Where do you stand on this? Do you like making bouquets? Are you growing sunflowers, and if so, which kinds? I’d love to hear more about what you are growing and arranging.

Bounteous July

Summer food is just so delicious. How great is it to go out in the garden, pick a few sprigs of herbs, a bunch of fruits and veg, and then make something simple and full of flavor? I love this way of living. July is definitely the month where everything starts to happen; tomatoes come ripe, cucumbers double their size every day, picking beans is a daily occurrence, and the herbs are always a minute away from flowering. We are often gone for the last half of July on vacation, but along with many of you, we are continuing to shelter at home, which means that we are here to witness the wave of produce coming in. Usually the neighbors, and whoever is housesitting for us, get the benefit of it. I’m feeling behind, and the harvest has barely begun!

A great recipe to use up all the bounty is Panzanella. This is one of those ingenious dishes that was ‘invented’ to use up any ingredients to hand. Overripe tomatoes? the last few olives or capers sitting in oil? half a cucumber in the fridge? baguette going stale on the counter? Check, check, and check. We always have extra baguette from Adam’s bakery in the freezer, and right now the tomatoes are ripening faster than we can eat them (I really must get canning). You can find a ratio of ingredients anywhere, but I suggest you start with what you have.

I found some beautiful fresh spring shallots at the market this morning, but you can use onions. After slicing one small fat bulb thinly, I soaked them for a couple of hours in a tablespoon or so of red wine vinegar, to take out the harsh raw flavor, and then dumped the whole mess in. I used two pounds of tomatoes, chopped into bite-sized pieces if they were large, and sliced in half if they were cherry tomatoes. I used a small cucumber, seeded and peeled. I used two cloves of garlic, grated. I made a dressing of 1 Tbsp of red wine vinegar whisked with 1/2 tsp of homemade grainy mustard (thank you Liz!), then added about 3-4 Tbsp of olive oil. I used a handful of torn basil leaves, and a few fresh oregano leaves. Plenty of salt and pepper. About 1/2 cup of good black olives, drained and sliced, or you could use a few tablespoons of drained capers. The baguette, cut into big chunks and toasted with olive oil and salt in the oven until very crisp. About a cup of fresh mozzarella cut into small cubes. You can add a pinch of red pepper flakes if you wish (I did not). Let it sit about four hours on the counter to marry the flavors.

This is a hearty side dish that will work well with any summer meal, or you could add some grilled chicken or shrimp and call it your main course.

I got a text from a friend (and home gardener) who is having a glut of peaches and hot peppers. It was fun to exchange recipes and ideas. I’d love to know what you’re harvesting, and how you’re cooking it - we would all benefit from your brilliant home cooking ideas. Feel free to add to the comments section!