The Benefits of Wasps

Many years ago, Kate attended a local summer Girl Scout camp, which took place in a secluded canyon in Briones Regional Wilderness, which spans four cities and is a haven for wildlife. One of the highlights of this camp was that the girls learned how to cook lunch over a campfire, and did this (with the leaders' help) every day. We're not talking hot dogs and hamburgers; we're talking cast iron dutch ovens on coals, and using box ovens, to cook everything from taco casserole to potato and bacon hash. Dessert always followed; cake or cobbler, with ice cream made in hand-cranked buckets, natch. It was fun. Messy and a little dangerous, but fun. There was one major problem every year, and this was yellow jackets. The tiny beasties would swarm the picnic tables in droves. Everything had to be constantly covered. Girls, aged 5-15, screamed repeatedly. There was always a group of them running down or up a canyon, screeching about the 'bees.' 

My job at this camp was nature leader, so, me being me, I did a lot of research about the yellow jackets and incorporated some of what I learned into the lessons, hoping to calm fears. For instance: Did you know that yellow jackets are one of nature's best garbage collectors and composters? Without them, we'd be knee-deep in detritus. Yellow jackets also eat insect pests that bother us and eat our crops, like flies and caterpillars. I often find them, in the heat of summer, scavenging dying bees from the 'graveyard' under my hive. They take those back to their nests and feed them to their young. Yellow jackets even pollinate flowers, like in the photo above, something I never knew before today. I watched this lady long enough to take the picture and fire it off to my insect professor, who wrote back immediately: "Yes indeed, they love pollen and any sweet liquid like nectar!" It's hard to hate anything that pollinates flowers.

The problem, of course, is that they are so aggressive. They get into our food when we try to eat outside. They drop into soda cans, surprising the drinker on the next sip. They can sting repeatedly without any repercussions. It's so freaking annoying. I hate them hovering around the chickens, eating any tidbits I put out for them. If the yellow jackets nest in your yard, they are very hard to eradicate. As my dad found out, last summer, in his own yard, they are not deterred by any kind of bee suit and will sting through them with abandon if their home is threatened.

Yellow jackets are social creatures, just like bees, and in fact are in the same family as honeybees and ants (Hymenoptera). The queens, newly hatched in fall, overwinter in leaf litter. In the spring, they emerge and find a place to start a nest. They eat until they are strong enough to start laying eggs. This is happening right now, here in CA. A yellow jacket trap placed outside now might just catch queens, and prevent a hoard of worker wasps over the summer. The only one I've found that works is this one.

Image credit: PestWorld

Another wasp that we often find around our homes and gardens is the Paper Wasp. These tend to make their nests under overhanging eaves. I have a group that nests every year in the shallow eaves under Adam's train shed. Paper wasps are great pollinators, but their true benefit comes from the fact that they are very efficient hunters of caterpillars, beetle larvae, and flies. They attack them and take them back to their nests to feed their young. They are aggressive if bothered, but mostly just stay to themselves. They don't care about our picnic dinners, which means they are very polite guests in the home garden.

Image credit: Bugguide.net

Then there are all the myriad kinds of predatory wasps, most of which you'll never see, which parasitize caterpillars. This means they lay their eggs in the body of the caterpillar, which then hatch and consume the caterpillar from the inside out. Yuck, and cool!

So the next time you see a wasp of any kind in the garden, instead of freaking out, try to focus on the fact that they perform an important service for us. I'm not saying not to kill them; my patience is often tried to the limit with yellow jackets. But just give it some thought before automatically switching into 'destroy' mode. 

Foliar Feeding Experiment/Overview of Nutrition requirements of Plants

(Thank you to Laura Forlin, co-chair of the Merritt College Horticulture Dept, for teaching me all this stuff.)

We completed our Foliar Feeding Experiment yesterday in lab. The results were interesting, and I want to share them with you. But before I do that, we need to review a couple of things.

What do plants require to grow, thrive, and set seed? 

An element is essential if: 1) A plant cannot complete it's life cycle without it; 2) no other element can perform the same function; 3) it is directly involved in the nutrition of the plant; and 4) missing or insufficient supplies adversely affect plant growth.

There are three macronutrients that everyone forgets, they are non-mineral, and they are required in larger quantities than any of the others. Can you guess what they are?

They are obtained from the atmosphere and water.

Yes! Oxygen, carbon, and hydrogen. 

The next six elements are macronutrients and are the most important after the big three: Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), and Sulfur (S). These are required in large quantities. N, P, and K more than the others. 

The next eight are micronutrients - still essential, but required in much smaller amounts: Chloride (Cl), Iron (Fe), Boron (B), Manganese (Mn), Zinc (Zn), Copper (Cu), Nickel (Ni), and Molybdenum (Mo). 

Many of these are present in the soil already and you may not need to supply them. Knowing your levels of nutrients can be important, and that's why folks do soil tests, to discover what is lacking and add it in appropriate amounts. Now this is important: TOO MUCH FERTILIZER CAN BE WORSE THAN TOO LITTLE. I cannot stress this enough. If you just add chemicals willy-nilly, they will either be leached out quickly (entering the water supply, affecting organisms downstream) or they will damage your soil and plants. 

MOST SYNTHETIC FERTILIZERS HAVE HUGE AMOUNTS OF THE NUTRIENTS. You buy something like a 16-16-16, that's super hot. Putting that on your plants can be very damaging. Most synthetic fertilizers are completely water-soluble, meaning they enter soil solution quickly, are taken up quickly, and are leached quickly. It's wasteful, it's expensive, it can damage your plants, it can kill your soil microorganisms, and it damages the environment. If you've decided that you need to fertilize your plants, ORGANIC FERTILIZERS ARE THE WAY TO GO. They have a much smaller percentage of nutrients (like 3-3-3), most are only partly water soluble (which means some will be available right away, and some needs to be mineralized by the soil life first, giving you longer lasting nutrients; it also means less will be leached quickly from the soil and cause environmental problems), and they are made from products which are found in nature, and are often made out of waste-stream materials like feather meal, blood meal, bone meal. CHECK THE LABELS ON THE PACKAGES to know what you are getting and how high the percentages are.

Container plants will need regular feeding because they are disconnected from the soil life. BUT - if you are adding lots of organic matter to your in-ground beds, mulching, using cover crops, crop rotation, etc - you probably won't need much in the way of fertilizers at all. The only way to know for sure is to test your soil. 

Image Credit: Lowe's

You can buy a simple home-testing kit for about $10, which is really all most of us need - they aren't perfectly accurate but will give you enough of a result to figure out your imbalances. However, if you're feeling adventurous and you want some serious results, you can send your soil away to be tested at a lab. For a more conventional nutrient test, you can send a sample to U Mass. It costs very little, and you'll get a very interesting report. They will also give you recommendations based on your nutrient levels and soil texture. This is a fine way to go, but it's maybe not the most important test you can do.

You see, the microorganisms present in your soil determine your soil health. They are the ones who process the minerals and make them available to your plants. If you really want to know how alive your soil is (and you want it to be very, very alive), you could send a sample to Earthfort. They will test to determine the amounts of bacteria, fungi, nematodes (beneficial and detrimental) and protozoa in your soil. They can also tell you the percentage of organic matter. This costs a bit more, but it's probably worth it. I haven't done this yet, but I very much want to. 

So that's an overview of nutrition. Now I want to tell you the results of our foliar feeding experiment. 

The reason we even did this experiment is because of all the hype surrounding foliar feeding. Search for it on the internet, and you'll get some fabulous claims.  Let me be clear: the science is definitely not there to support those claims. There just isn't enough peer-reviewed data to say definitively that foliar feeding works. Plus, plant biology doesn't really support anything being taken up by the leaves. Each leaf has stomata, little openings on the undersides, which allow for gas exchange. But they don't take anything else up in there. So how does a foliar substance get in the leaf in the first place? It hasn't been discovered, if it exists. Also, there is a translocation of nutrients within the plant, but the nutrients themselves come from the roots. Photosynthate moves down, nutrients move up. Mostly. Not always. Things can be reallocated around the plant if need be. But there is no pathway from the stomata to the xylem or phloem from the stomata. 

There IS evidence that spraying microbiology on the leaves, like with compost tea, provides a coating on the leaf that is helpful in many ways. The leaves need good biota just like the roots do. It can protect them from predators, keep them from being sunburned, allow good stuff to live on the surface. It's just that it isn't clear that anything actually ever gets in the leaves except gases. 

Our teacher, Laura, wanted us to try an experiment to see if we could get any definitive results. Once the plants (chard for my team, again) germinated and had a couple of leaves, we began to cover the soil and spray only the leaves with macronutrients. We sprayed some with organic all-purpose fertilizer, and some with synthetic all-purpose fertilizer. We also had several controls that got soil drenches of these same fertilizers. We drenched the soil of each plant with micronutrients each week so that wouldn't be a limiting factor. The soil surface of each plant was covered with fresh plastic wrap each week, so no accidental dripping from the leaves would occur. The controls were covered as well so we could make a comparison.

Spoiler alert: They all did horribly. Even the controls weren't so hot, we think because the soil was covered each week and there was a lack of oxygen.

Here's our best-looking control:

Really floppy. Not good strength. Nice color, but not a lot of growth.

Here is an example of one of our foliar-sprayed plants. Remember, this plant got zero macronutrients other than on the leaves.

Just terrible. It's very chlorotic, and it didn't grow at all from the time we started spraying until the end of the experiment. What a total waste of a plant.

So there you have it. Foliar sprays are really a waste of time. Unless you feel that you need some good biota on the leaves, you can skip it. Add your inputs to the soil itself. Making compost tea is fine, but just drench the soil with it, where it can do some real good. Don't bother with the spraying.

***** edited 5/1/18  Talked to a fellow student last night who is doing his own foliar feeding experiment at home with tomato plants. He is spraying with a calcium/mag supplement and getting terrific results compared to the controls. So it just goes to show that more research is needed in this field! Different nutrients on different plants might react differently!!! Take my experiment with a grain of salt, and look for other scholarly papers on this subject. 

New Tomato System

I think I write those same words about this time every year, don't I? It feels like we've tried every method, and they all work fine. Mostly. Not perfectly. I still haven't found the perfect system. I'm going to keep trying new things until I find it!

This year, I decided to plant about half the tomatoes I did last year - only 32. One (or two) of each of my favorite varieties, and some new ones to see if I find a new obsession. I'll list the tomatoes we have with links to their descriptions below. (I know some of you are as smitten with tomatoes as I am!) The problem with growing ~70 plants last year is that there wasn't room for anything else. And I missed home-grown corn! winter squash! melons! pole beans! And all those plants require a lot of sun. So all those things are going in the sunniest spaces, along with peppers (both sweet and hot) and cucumbers, which we never go without. Plus I have a whole bed of basil and collards. Whole beds of cilantro and dill. It feels diverse and fun, after a yard full of tomatoes last summer. 

However I still wanted lots of tomatoes. So I knew I needed to find a system where I could plant more closely. Enter: Staking and Pruning. Each tomato plant has its own stake and will be trained to climb up it (basically, that means I tie it up a lot), and each plant will be pruned to only the leader. No side shoots allowed. This should keep them tidy, with plenty of airflow around them. 

Does this mean more work for me? Um, yes. I'm going to have to spend some quality time every week in the tomato patch, keeping things ship-shape. I'm also probably going to have to amend the soil at some point with some organic, all-purpose fertilizer, or more compost, or worm castings. Luckily the soil is in top form after all those covers this winter.

I usually use tomato twine to keep things tied up, which is fine - soft and durable. But I wanted something a little more sturdy for the bottoms of the plants as the main stem grows thicker and stronger. So I found this sort of velcro strapping - and I love it.

I have them nice and loose right now, to leave plenty of room for the stem to grow. We'll see how these fare as the pressure on them grows greater, but as of right now, they are terrific.

What system have you decided to use in your garden this year?

Here's a list of the tomatoes I'm growing, with links to their descriptions.

Cherry: Sungold, Austin Red Pear, Beam's Yellow Pear, and two new ones, Green Vernissage, which is leading the race and is the tallest tomato in the patch, and Black Vernissage. We always plant a few cherries because they ripen first and give us our first tomato taste of the season while the bigger guys ripen. Also, Tom likes to go out and pick a pint-jar-full every morning to take to work, either with cucumbers and rice vinegar, or with fresh mozzarella and basil.

Slicers/Beefsteak: Italian Heirloom (technically a slicer but meaty like a paste, I planted two), Dester, Big Dena (new to us), Black from Tula (new to us), Black Krim, Cherokee Purple, Kellogg's Breakfast, Martha Washington, Carbon (new to us), Pink Berkeley Tie Dye, Dr. Wyche's Yellow, Mortgage Lifter, Vorlon (new to us), Black Beauty (new to us), Kolb (new to us), Pineapple (new to us), and Crnkovic Yugoslavian (new to us). I have a lot of dark colored tomatoes and yellow tomatoes. The yellow ones seem to go later into the fall and form the backbone of our late summer/early fall production. The purple ones seem to have the deepest flavor. 

Paste/Plum: Gezahnte (new to us, I've planted two), Cour di Bue (new to us), Ukrainian Purple, Hungarian Heart (I planted two), Opalka, Amish Paste, and Sheboygan. I use these mostly for cooking down into canned goods. I like paste tomatoes that are very large and thick, because they seem to do better resisting blossom end rot.

So, here's to tomatoes, and here's to summer! It was 89 degrees in our yard yesterday afternoon, but it looks like we're going to cool down again, thankfully.

Clover Cover

I've already written about the excellent cover that our wheat/oat crop provided for the vegetable beds over the winter, but I failed to mention that I also seeded crimson clover at the exact same time I seeded the wheat, with the hope that it would provide nitrogen over time to other plants. It's done well everywhere I planted it, except the garlic bed, for some unknown reason. You can see it flourishing in the picture above. It's a lovely cover crop. But today I cut most of it down, because it's finally tomato-and-pepper-planting-time, hooray! However, before the clover is relegated to compost, chickens, or mulch, I wanted to show you what it can do for you in your garden, and why I planted it in the first place. 

Nitrogen nodules on the roots of the clover

There's a huge amount of nitrogen in the air around us, but it's in a form that is very difficult to access because it has a very strong bond. As you probably know, lightening can break apart those bonds and cause nitrogen to become available to plants in rain. Also, the Haber-Bosch process, used originally to make bombs, is what makes synthetic nitrogen for fertilizers now (like Miracle Gro). This process requires a huge amount of energy and personally I will never use synthetic nitrogen for many reasons including that one. However, some plants have evolved to provide their own nitrogen; those in the Legume family have this skill.

Clover is a legume, so like every plant in that family, it has the ability to form a relationship with a special bacteria which provides nitrogen to the plant. This rhizobia bacterium, when invited by the plant, invades the roots of those leguminous plants. The plant gives up some carbohydrates in the form of sugar exudates to the rhizobium, which in turn makes tiny anaerobic nodules on the roots which have the ability to fix nitrogen. Those are the pink nodules you can see on the roots above. 

This nitrogen generally is fixed within the bodies of the bacteria, and doesn't become available to other plants (through the soil solution) until the plant is cut down and the roots decompose. It's important to time all of this correctly: You want to grow the leguminous plants until nitrogen has been fixed, then cut off the tops of those plants before they set seed (if the plant sets seed, it has used up all the nitrogen stores for itself), and allow the tops to compost in place on the soil, while the roots and nodules decompose deep within the soil. 

The nitrogen-fixing ability is true of any leguminous plant - clover, peas, vetch, favas, alfalfa - as long as the bacteria is present, which it is in healthy soil. You can allow them to bloom and feed the pollinators, but chop it before it sets seed. Then mulch the next set of plants with the tops that you've cut off. Above are my sweet peppers, the soil totally covered with the clover tops. These will decompose in place, allowing nutrients back into the soil. You don't have to mix them in, the soil microbes will do that work for you. And as they break down, they will retain moisture, shade the soil, and prevent weeds from germinating. Plus add nutrients naturally!

Meanwhile, it makes a beautiful flower display that my bees adore!

I've had such success with winter cover crops this year that I intend to use them every year; I'll just plant them within the rows of vegetables. I'd like to figure out how to do this with a summer cover as well. Buckwheat works well here as a summer cover and I've used it before by itself; the trick is to use it in between the growing food crops. I am doing a little of this already using intercropping with other vegetables. For instance, I'm growing pumpkins and butternut squash underneath the corn, and basil around and in the hot peppers. I'm always worried about growing anything below the tomatoes because of air circulation; but I have all our wheat and oat straw to cover the soil there. Beans and cucumbers quickly cover the soil with their own leaves. 

Have you used cover crops or intercropping in your garden? If so, I'd love to hear about your results. Please share in the comments. 

Syrphid Flies

This beautiful creature is a Syrphid Fly, also called Hover or Flower Fly. I found her on one of my Gaillardia plants a few weeks ago. I'm so excited that there are Syrphid Flies in my garden because they are so beneficial!

Syrphid Flies (of which there are many) mimic honeybees and wasps as a defensive camouflage; they do not sting, but want bigger predators to think they might. The adult flies are fabulous pollinators, eating both nectar and pollen. The larvae of some types are voracious predators of aphids, which is probably why I found this one in my garden. The eggs hatch and develop into larvae which eat a lot of aphids - in fact there are three larval instars (or phases) of some kinds of Syrphid Flies. I don't know about you, but I'm seeing way more aphids than I usually do, so anything that can help me control them is terrific! I'm hoping this fly laid lots of eggs on my aphid-ridden blanket flower. 

There are also Syrphid Flies that develop in stagnant ponds and eat decaying organic matter while in the larval instars. They form unique larvae called 'rat-tailed maggot.' The rat tail is a siphon that allows the larvae to breathe while in water. I first heard about this kind of hover fly from a professor in the UK that I like to follow - he has great books - and a great You Tube channel with lots of interesting pollinators. I'm not sure this kind of fly lives here, but I made his 'hover fly lagoon' anyway, to see what comes of it. It's quite easy - you just need a container filled with water and organic matter.

I went begging my neighbor for some of his long, weedy grass to use in this lagoon, since Dr. Goulson says this is the best kind of organic matter to use. I'll let it fester (I put it a long way from the back door!) and see what grows there in a few months. Should be interesting. One thing I'll need to do is check the water level frequently and watch that it doesn't dry out. I'll keep you posted!

Again, though, aphids will bring in the kind I took a picture of above. So you don't need to do anything except STOP USING PESTICIDES. Nature sends in predators when prey develops. And if you use pesticides (chemical or organic), you'll kill the good guys along with the bad. So far this year in my garden, the aphids have brought in: lady beetles, green lacewings, snakeflies, predatory mites, and syrphid flies. Plus probably others I haven't even noticed yet!

Here is the video from Dr. Goulson about this project. His books are worth reading, as well, if you have interest in native bees.