SICKNESS, MY CORN NOT ME

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An Interesting Puzzle Unfolds

Sudoko and Scrabble and other games and puzzles offer endless hours of entertainment and stimulation. Or so I hear.  I get those challenges and rewards from my garden. Case in point is a bed of sweet corn which has been stunted all season long and then last week, almost suddenly, all the plants’ leaves turn sickly as well. Needless to say, ears are developing poorly or not at all. Why, I asked?

I have to backtrack. Each year I plant 4 beds of corn, each about 20 feet long, which supplies plenty of ears for fresh eating and freezing. I spread out the harvest season by planting a new bed every two weeks after the previous planting. Each bed, like other beds in my vegetable gardens, is spread each year with a one-inch depth of compost to maintain fertility (as well as other benefits).
Tall Golden Bantam corn
At first I thought perhaps there was a fertility problem with the stunted bed. But, as I wrote, all the beds get the same fertility treatment. Watering is also the same, via drip irrigation. And early-season Chinese cabbage plants sharing that bed with the corn look fine and healthy.

The suddenly sickly leaves were very telling, with yellow streaks that turned to tan, dead spots. It didn’t take long to nail down the cause to Stewart’s Wilt, also known as bacterial wilt. Two culprits are at work here. The first is a bacterium (Pantoea stewartii), which needs a friend to actually get inside and infect a corn plant. That friend is the corn flea beetle (Chaetocnema pulicaria). The beetles overwinter as adults, with the bacteria in their gut, and emerge in spring to feed on and infect corn plants. Seeds from infected plants can also grow up infected, although this is relatively rare.

Other evidence supports my finger-pointing. The corn flea beetle doesn’t tolerate cold weather well, making the disease more prevalent after milder winters. Check. Last winter was the warmest winter in decades. Stewart’s Wilt is also most prevalent in hot summers and dry summers. Check. Check. One of the most susceptible varieties is Golden Bantam, which I grow. Check.

Disease development

Disease development on leaves

Fertility can play a role, with ammonium nitrogen and high phosphorus levels favoring the disease, and high calcium and potassium decreasing plant susceptibility. Probably not a factor; phosphorus level is high in my beds, as are levels of potassium and calcium. Based on growth in the rest of the garden, there’s no reason to suspect ammonium levels are too high.

Why This Year?

Putting a name to the problem is not the end of my puzzle. 

One remaining question is why the one bed was so severely infected, and not the other three. Golden Bantam is an heirloom variety, with seed saved each year — for the past 100 plus years — from self-pollinated plants. Although basically the same, all Golden Bantam plants are not clones, that is, genetically identical. Slight differences could exist between “lines.” I had more than one source of Golden Bantam seed this year. I always assumed that all the Golden Bantams are sufficiently identical, so I never record which source or sources I planted in each bed. It could be that one bed was planted with seed of a more susceptible line.
Infested bed
Another possibility for the unique performance of the last bed could be that it’s development coincided with the flea beetle’s development such that it was rendered more susceptible. Earlier ripening corn generally is less susceptible than later ripening ones.

I’m tending toward the theory that this growing season presented a unique “perfect storm” of conditions that favored the disease.

Looking Forward

The most important part of solving this puzzle, of course, is: what to do? I don’t particularly like the flavor or texture of modern supersweet hybrids, even if many are wilt resistant. Some popular old varieties — Country Gentleman and Stowell Evergreen, for example — are wilt resistant. But — and not to be a picky eater — those varieties are white corns; I like yellow corns.

More than that, I like Golden Bantam sweet corn. This variety was the most popular variety early in the 20th century. Although the pathogen was identified by, of course, F. C. Stewart in Long Island, New York in 1895, not much could be done to control its devastating effects until resistant hybrids were developed. The first of these was bred from two lines of Golden Bantam, in 1923. It wasn’t long before 70 tp 80% of canned corn was of this variety, Golden Cross Bantam.

Golden Cross Bantam is still available today. The plants are sturdier, more productive, more uniform in ripening than Golden Bantam, and wilt resistant. I’ll plant it next year. (I may have accidentally grown it a few years ago. Given Golden Bantam’s popularity, “Bantam” was included in the names of many hybrids and genetic lines. For more about my experience see my blog post from September 1, 2016.) I hope Golden Cross Bantam, seed of which I already ordered, tastes as good as my original Golden Bantam.

I’ll also plant a few hills, labeled as to seed source, of the real Golden Bantam to see if Stewart’s disease appears and, if so, if severity varies between those sources.

Puzzle complete, till next year.

Golden Bantam, a hit since 1906

Golden Bantam, a hit since 1906

BLUEBERRY GROWING WEBINAR REDUX

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•For anyone who missed my recent 90 minute webinar on Growing Blueberries, the webinar has been recorded and is available soon for a limited time period on-demand for $35. The webinar covers everything from plant selection to planting to maintenance to pests to harvest and preservation. Including, of course, the all important getting the soil right and dealing with birds.

•After this webinar, you will be really good at growing blueberries! 

•Contact me before 9 am EST August 20, 2020 if you’d like to view the webinar.

FINAL REMINDER FOR BLUEBERRY GROWING WORKSHOP WEBINAR ON AUG. 12, 2020, FROM 7-8:30 PM

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Final reminder for my zoom Blueberry Growing Workshop/Webinar on August 12, 2020 from 7-8:30 pm EST. I’ll cover everything from planting right through harvest and preservation. If you’re new to growing blueberries, you’ll learn how to grow this fruit successfully. If you already grow blueberries, you’ll be able to grow them better. If you’re an expert on growing blueberries, you don’t need this workshop/webinar. Registration ($35) at https://us02web.zoom.us/webinar/register/WN_NSTrunuTRkOcRfS-frQuYg. For more information, go to https://leereich.com/workshops.
Bunch of blueberries

BLUEBERRIES AND ASPARAGUS (SEPARATELY)

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All Good

I’ve never met a blueberry I didn’t like. Then again, I have yet to taste a rabbiteye blueberry (Vaccinium asheii), native to southeastern U.S. and highly acclaimed there. I also have yet to taste Cascades blueberry (V. deliciosum), native to the Pacific northwest. With “deliciosum” as its species name, how could it not taste great? And those are just two of the many species of blueberry that I’ve never tasted that are found throughout the world.

BLUEBERRY FRUITING BRANCHThe blueberries with which I am most familiar are those that I grow, which are highbush blueberry and lowbush blueberry. I grow blueberries because they are beautiful plants, because they are relatively pest free, because they are delicious, and because they fruit reliably for me year after year. 

I have to admit that highbush blueberries, at least to me, all taste pretty much the same. They have nowhere the broad flavor spectrum of apples. Tasting the same is fine with me; as I wrote, they are delicious. Depending on the variety, the berries do vary in ripening season, size, and other less obvious characteristics. One very important influence on flavor is how they are picked. Blueberries turn blue a few days before they are at their peak flavor, which is okay if you’re marketing them and just want them blue. But the best tasting tasting, dead-ripe ones are those that drop into your hand as you tickle a bunch of berries, which makes a good case for growing them near your back door.

Lowbush blueberries also taste pretty much the same from plant to plant, but their flavor is decidedly different from that of highbush blueberries, a more metallic sweetness. Few varieties of lowbush blueberry exist, so most plants are just random seedlings anyway. Not to disparage that, though; they’re also all delicious — if picked at the right moment.
Lowbush blueberry blooming

A Different Blueberry

My idea that all highbush blueberries taste pretty much the same was recently challenged. New highbush varieties have been bred or selected since this native fruit went, over the past 100 years, from being harvested from mostly from the wild to being mostly cultivated. Over the years I’ve been very pleased with the nine varieties I had been growing, spreading out the harvest season from late June until early September.

Then the new variety, Nocturne, bred by Dr. Mark Ehlenfeldt of the USDA, caught my eye. Besides being billed as having unique flavor, Nocturne was also said to be notable for its jet-black fruits which, before they turn jet black, are vivid red-orange in color. What attracted me wasn’t the fruit’s unique colors, but its allegedly unique flavor atypical, so the description read, of either rabbiteye [which is in Nocturne’s lineage] or highbush.”
Nocturne blueberry
So I called Mark to learn more about the variety. One of the original breeding goals back 25 years ago, when Nocturne’s carefully selected parents were mated, was to get a rabbiteye variety that, blooming later than most, would be less susceptible to spring frosts. Chemically, two significant differences between rabbiteye and highbush blueberries are their organic acids. Rabbiteyes have mostly malic and succinic acids, yielding a flatter taste profile than highbush fruits, whose citric acid makes for a brighter, sharper flavor. Other species were also thrown into the mix, including Constable’s blueberry (V. constablaei), a native of higher elevations in southeastern U.S., and contributing late blooming and excellent flavor.

Long story short: Nocturne is significant for being a variety with significant rabbiteye parentage that is winter hardy to well below zero degrees Fahrenheit and late blooming. It has excellent flavor, juicy sweet, and sprightly, and quite different from my other highbush varieties. Nocturne tastes even juicier than it is. Which do I like better? Neither, I like them all. Nocturne, now in its third year here on the farmden, now has a permanent place in my Blueberry Temple.

Blueberry Temple

Blueberry Temple

Learn the Ins and Outs of Growing Blueberries

If you have the space, grow blueberries. To that end, I will be holding a zoom workshop/webinar on growing blueberries on August 12, 2020 from 7-8:30 pm EST. I’ll cover everything from planting right through harvest and preservation. If you’re new to growing blueberries, you’ll learn how to grow this fruit successfully. If you already grow blueberries, you’ll be able to grow them better. If you’re an expert on growing blueberries, you don’t need this workshop/webinar. Registration ($35) is a must as space is limited; registration link is

https://us02web.zoom.us/webinar/register/WN_NSTrunuTRkOcRfS-frQuYg. For more information, go to https://leereich.com/workshops.

Asparagus Redux

On a totally different topic, I’d like to followup on my end-of-harvest-season treatment of asparagus. Weeds have always been somewhat problematic in my asparagus bed. Harvest ceases at the end of June so plants can grow freely and feed energy to the roots which will fuel the following year’s spears in spring. Weeds quickly move into this hard-to-weed area.

As I wrote on this blog a few weeks ago, this past June, at the end of asparagus harvest season, I mowed everything, weeds as well as emerging asparagus spears, to the ground with my scythe. I then blanketed the ground with a thick mulch. I first laid down an inch depth of compost, which will feed the soil as well as smother roots, and then topped that with another inch or two of wood chips.

There was the danger of smothering the emergence of new asparagus shoots, but plenty have pushed up through the mulch.

As far as weeds, there are very few. Most of them appear at the grassy edge of the bed.

Success!
Mulched asparagus

DRIP WORK

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Many Benefits of Drip

I’m a big fan of drip irrigation, an irrigation system by which water is frequently, but slowly, applied to the soil. It’s better for plants because soil moisture is replenished closer to the rate at which they drink it up. With a sprinkler, soil moisture levels vacillate between feast and famine.

Because of the efficient use of water, drip is also better for the environment, typically using 60 percent less water than sprinkling.
Dripline with beans
And drip is better for me — and you, if your garden or farmden is dripped. By pinpointing water to garden plants, large spaces between plants stay dry so there’s less weeds for us to pull. And best of all, with an inexpensive timer at the hose spigot, I turn on the system in April and then pretty much forget about watering until the end of the growing season.

Troubleshooting

Today I was reminded about the “pretty much” part of being able to forget about watering until the end of the season. My drip system is set up so that same main line that quenches plant thirst in my two vegetable gardens continues on to water about twenty potted plants. Or not!
Drip tubes to potted plants
I noticed yesterday that some of the potted plants were dry and assumed that the emitters bringing water to these pots were defective. Turns out that sometimes they dripped and sometimes they didn’t. Hmmm. I kept switching around and replacing the “defective” emitters and by the end of the day, for some reason, they were all working. Problem solved.

No! I have a hose connected near my well pump so that I can occasionally hand water some melons I’ve planted in a truckload of leaves a local landscaper provided me with last autumn. Water pressure was very low. 

Long story short is that the seasonal line from the well to the pump has a short section of flexible, almost clear plastic tubing. Sun shining on the tubing grew a nice crop of algae within. I disconnected the tube and was able to remove an almost intact tube of algae that had been clogging the line. That was the culprit responsible for the capricious behavior of the drip system and the sluggish behavior of the hose for hand watering.

Thorough cleaning and reconnecting the tubing, wrapping it in aluminum foil to exclude light, priming the pump, and cleaning the sediment filter in the drip line had everything working waterly again. Geez, you gotta be a rocket science to keep things working smoothly. Well, not quite.

I’ve now marked my calendar to check the drip system every 3 weeks.

Some Attention Necessary

In addition to checking periodically to make sure that the water flows unobstructed, my watering system — any drip system —  requires other regular attention, including a small amount of hand watering. The reason has to do with the shape of the wetting front drip presents in the soil. As a drip of water enters the ground, gravity pulls water downward at the same time that capillary action is pulling the water horizontally.  Down in the ground, that wetting front is shaped like an ice cream cone, at first widening with depth and then narrowing to a point.

The width of the cone depends on soil porosity. Clay soils have small particles with commensurately small pores (illustration from my book Weedless Gardening).
Wetting front various soil types
Those small pores exert a strong capillary pull so the ice cream cone spreads wide, as much a six feet at its widest down from each point source of water. At the other extreme is a sandy soil, whose large particles have large spaces between them and comparatively little capillary pull; the result is a slender ice cream cone, spreading no more that a couple of feet wide.

A drip system is a series of emitters, so the wetting fronts can merge together at their widest points presenting a wetting front that in soil cross section looks like waves below ground, with peaks at ground level at each emitter. (This illustration is also from Weedless Gardening.)
Wetting fronts, merging
Distance between peaks depends on the spacing of drip emitters. Depth of the wave troughs between the peaks depends on the soil texture and emitter spacing. A soil rich in clay with close emitter spacing would be wet at the peaks, with the “waves” relatively close to the ground surface between the peaks.

Between emitter peaks, the ground is dry near the surface. Plant a seed there and, in the absence of rain, the seed will just sit. Tuck a transplant into the soil there and, in the absence of rain, it will dry out and die. Hand watering gets that seed or transplant’s roots growing; once the roots reach down far enough to tap into the wetting front, they’re on their own.
Watering by hand
To avoid hand watering I sometimes move the drip line right over the row where I planted seeds or right along the row where I set transplants. After a few days or once seeds sprout, I move the drip line back to its rightful position which, along with one other line, is about 9 inches in from each of the outer edges of my 3 foot wide vegetable beds. 

Only one more maintenance item for my drip system. If it has rained cats and dogs, that is, more than 1 inch, as measured in a rain gauge, I might turn off the drip system temporarily. Then — and this is very important — I’ll stick a Post-It note  on which is written “Drip” to my bathroom mirror as a reminder to turn the drip system back on in due time. Drip irrigation is low maintenance, but not no maintenance.

ENTERING THE TWILIGHT ZONE

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Bigger Garden, Same Size

Over the years I’ve greatly expanded my vegetable garden, for bigger harvests, without making it any bigger. How? By what I have called (in my book Weedless Gardening) multidimensional gardening.

I thought about this today as I looked upon a bed from which I had pulled snow peas and had just planted cauliflower, cabbage, and lettuce. Let’s compare this bed with the more traditional planting of single rows of plants, each row separated by wide spaces for walking in for hoeing weeds, harvesting, and other activities. No foot ever sets foot in my beds, which are 3 feet wide. Rather than the traditional one dimensional planting, I add a dimension — width — by planting 3 rows up that bed. Or more, if I’m planting smaller plant such as carrots or onions.
Bed of lettuce and chinese cabbage'
Let’s backtrack in time to when the bed was home to peas. Oregon Sugar Pod peas grow about 3 feet tall, so after planting them in early April, I made accommodations for them to utilize a third dimension in that bed, up. A three foot high, temporary, chicken wire fence allowed them to grow up, flanked on one side by a row of radishes and on the other side by a row of lettuce.

Bed of onions

60 pounds of onions in 33 square feet!

There you have it, 3 dimensions. The bed length. The bed width, only three feet wide, with three or more rows down its length. And up.

A Fourth Dimension

Three dimensions isn’t the end of the story for multidimensional gardening. Time is another dimension. Neither peas nor radishes nor lettuce, occupy any bed for a whole season. Peas peter out in hot weather which, along with longer days, tells radish and lettuce plants that it’s time to go to seed. Those conditions tell me that radish roots are getting pithy and lettuce gets bitter, so out they go.

In my planting of cabbage, cauliflower, and lettuce, closer planting is possible because it allows room for longer maturing plants to expand as quicker maturing plants get harvested and out of the way. The middle row of the bed is planted to Charming Snow cauliflower, which will be ready for harvest around the first half of September. I can’t dawdle with that harvest because, left too long, cauliflower curds become loose and quality plummets.

I’ve planted Early Jersey Wakefield cabbage — an heirloom variety noted for its flavor — in a row eight inches away from the row of cauliflowers. The plants in the cabbage row are staggered with those in the cauliflower row, putting a little more space between plants from one row to the other. Early Jersey Wakefield will mature towards the end of September; no need to run out and harvest them all once they’re ready. In cool weather, the heads stay tasty and solid right out in the garden.

The row of Bartolo cabbage — a good storage variety — flanks the cauliflower on the other side of the bed. Bartolo requires 115 days to maturity.

Between each of the cabbage plants I’ve transplanted one or two lettuce seedlings. They’ll be ready for harvest and starting to get out of the way within a couple of weeks.

Mixing and Matching

How long a vegetable takes to mature, what kind of weather it likes, and the length of the growing season all need to be considered in order to make best use of four dimensions in the vegetable garden. Doing so, it’s often possible to grow three different crops in the same bed in a single season.

Here’s a table I made up listing some combinations that have worked well in my planting beds according to preferred temperature (cool or warm) and time needed until harvest (short, medium, or long season). That’s for here in New York’s Hudson Valley, with a growing season of about 170 days.
Examples of planting combinations
For example, looking at the first group, a tomato bed could start with lettuce, which will be out of the way by the time tomato transplants have spread to need the space. An example from the second group would be a bed with an early planting of turnips followed by a planting of okra followed by a planting of spinach.

A big advantage of these mixed plantings is that they present less of a visual or olfactory target for pests to hone in on, and they cover the ground enough to shade it to limit weed growth.

Lettuce and cucumbers

Lettuce and cucumbers

Carrots and lettuce following early corn

Carrots and lettuce following early corn

And Finally, the Twilight Zone, But Not For Now

Is it possible to find yet another dimension in the vegetable garden, a dimension beyond space and time? The Twilight Zone. Sort of. This fifth dimension is made up of a few tricks designed to find time where it is not, tricks meant to add days or weeks to the beginning and/or end of the growing season. But mid-July isn’t the time to detail ways of adding this dimension.

Trying to fill every available niche of physical space and time in the vegetable garden is like doing a four- (or is it five-?) dimensional jigsaw puzzle. Assembling this puzzle can sometimes bring on as much frustration as doing a real jigsaw puzzle. When I began gardening, I would sometimes get overwrought trying to integrate every multidimensional “puzzle” piece into every square inch of garden. Then I learned: When in doubt, just go ahead and plant.

BAD SEEDS? NO SEEDS?

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Edamame Scare

Got a couple of scares in the garden this season. No, not some woodchuck making its way past the dogs and then through some openings in the fences to chomp down a row of peas (which look especially vibrant this year, thank you). And no late frost that wiped out my carefully tended tomato transplants. 

The first scare came last week as I looked down on the bed where I had planted edamame a couple of weeks previously. No green showed in the bed, a stark contrast to the nearby bed planted at the same time with snap beans, the small plants enjoying the warm sunshine and neatly lined up four inches apart in two rows down the bed.

Testing edamame seeds

Testing edamame seeds

Scratching gingerly into the soil of the edamame bed did not reveal any seeds germinating but not yet above ground. In fact, I couldn’t find any seeds at all! Had I opened furrows and forgotten to plant seeds in them before covering the furrow? Doubtful, especially since I had planted another bed, still barren, in the other vegetable garden at the same time. Had a mouse or some other animal cruised underground enjoying a snack every four inches down the row? That would be a very thorough rodent. Plus, he or she would have left a tunnel.

Had the seeds rotted? Possibly, but that would be very quick for them to so thoroughly disappear. Had the seeds been old, which would make them more prone to rotting? I do save my own edamame seed every year, the variety Shirofumi, so that is a possibility. Except that I planted last year’s seed.

The mystery still exists but there was still time for action. I had additional Shirofumi seed left. Rather than just plant it, I’d test its germination, which I did by sprouting the seeds indoors. After an overnight soak in a beaker, I poured off the water and then rinsed the seeds twice daily. As it turned out seed from 2018 and 2015 didn’t germinate at all.

Last year’s seed germinated very well, and I planted them while their root sprouts were still very short. One week later, the plants have emerged. But the mystery still exists.Planting sprouted edamame

What If?

The second scare of the season is seed-related but hypothetical. What if seeds are unavailable next year, or any year? Or, at least, seeds of some of the varieties I want to grow.

This fear is not all that hypothetical. This spring, because of the surge in interest in gardening, seeds were harder to get.

And in years past, seeds of some of my favorite varieties of vegetables became difficult to find. Sweet Italia pepper, for instance, which I consider the best as far as flavor and early ripening for colder climates. My recourse has been to save my own seeds of these varieties for many years. In addition to Sweet Italia, I also save seed of Pink Pearl and Pennsylvania Dutch Butter popcorn, Otto File polenta corn, and, as mentioned above, Shirofumi edemame.

Sweet Italia pepperPopcorn hanging from kitchen rafters

This season, the plan is to save seed of more vegetables.

A few guidelines will make seed-saving a success. First, I won’t save seed from “F-1 hybrids;” they are produced with selected, different parents, so the saved seed will not yield the same variety as the seed that is saved.

Selecting seeds from too few individuals can result in inbreeding depression, or generally weaker plants. So my second guideline is to save a few seeds from a lot of plants, then combine them to put more genetic diversity into the seed packet packet. Saving seed from more than one plant also provides insurance just in case a seed plant dies.

Some vegetable plants — corn, onions, and the cabbage family, for example — are especially prone to inbreeding depression. Saving seeds from Otto File and my popcorns is especially easy since the seeds are dry and mature when ready to eat or save. When I twist the kernels off an ear for eating, I just take out a few to add to my growing seed packet of that particular variety.

Arugula (Cabbage family) flower and seedpod

Arugula (Cabbage family) flower and seedpod

A third consideration in saving seed is keeping the seed true to variety. Varieties of sweet corn readily cross-pollinate. Again, it is corn, onions, and the cabbage family that are among the common vegetables that readily cross pollinate. So I grow popcorn in one vegetable garden and sweet corn in the other, and Otto File corn out in my meadow between dwarf apple trees. If my Golden Bantam sweet corn were to grow too close to my Pink Pearl Popcorn, the resulting seeds will grow into plants yielding kernels that were less sweet or less poppable. 

Although squashes have separate female and male flowers on the same plant, which would make them prone to cross-pollination, that’s no problem here. Zucchini flower and fruitI grow only Sweet Mama and Waltham winter squashes. The first variety is botanically Cucumbita maxima and the second is C. moschata; the two species do not cross-pollinate.

Plants that can self-pollinate, such as tomatoes, peppers, beans, and peas, could be contaminated by pollen from other, nearby varieties. Tomato flowerDistance between varieties can prevent cross-pollination. So can fine mesh bags. I plan to use small organza bags normally sold for wedding favors.

And finally, good storage, meaning dry and cool or cold conditions, makes sure seeds germinate well. Which my edamame did not. Hmmm.

(For more depth in seed saving, see the excellent and thorough book Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners by Suzanne Ashworth.)

ALL FOR THE FUTURE

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Seeding Transplants? Again.

Only a couple of weeks ago I finished planting out tomato, pepper, melon, and the last of other spring transplants, and here I am today, sowing seeds again for more transplants. No, that first batch of transplants weren’t snuffed out from the last, late frost when the thermometer dropped to 28°F on May 13th.

Sowing lettuce seeds in flats
And no, those transplants were not clipped off at ground level, toppled and left lying on the ground, by cutworms. Neither were they chomped from the top down to ground level by rabbits.

I’m planting seed flats today to keep the harvest rolling along right through late autumn.

Future Further

Looking farthest ahead, I have in hand two packets of cabbage seed, Early Jersey Wakefield and  Bartolo. Early Jersey Wakefield is a hundred year old variety with very good flavor and pointy heads, due to mature a couple of months after transplanting. Once those heads firm up, they can keep well out in the garden for a few weeks in the cool, autumn weather. Those I set out in spring, once mature, are apt burst open from rapid growth in summer weather. Bartolo yields firm, round heads that store in good condition after harvest, well into winter. They are ready for harvest 115 days after transplanting.
Cabbages and kale interplanted in bed
I plan for any of today’s sowings to spend about a month in their containers before being planted out. Cooler weather and lowering sunlight dramatically slow plant growth around here by early October, so any late ripening vegetables need to be ready or just about ready for harvest by then. Bartolo cabbage, with 30 days in a seed flat plus 115 days out in the garden, is then ripe by . . . whoops . . . the END of October! No wonder Bartolo often didn’t ripen for me in the past. (Nothing like writing about my garden to keep me honest and awake. I should re-read the detailed timing schedule I wrote in Weedless Gardening for various vegetables in various climates.)

Okay, all is not lost for winter storage cabbage. Warm weather, timely water from drip irrigation, and soil enriched with plenty of compost might speed maturity along faster than predicted. Unseasonally warm weather through October would also help ripen nearly ripe heads. And there’s always the fallback, with sure-to-ripen Early Jersey Wakefield.

Still on time, guaranteed, will be today’s sowing of Charming Snow cauliflower, maturing 60 days from transplanting.

That’s it, for now, for the cabbage family. Later on in summer I’ll be sowing Chinese cabbage seeds. Perhaps more kale also, although spring sowings of this almost perfect vegetable can carry on right into winter, even spring if the winter is sufficiently mild.

Future Sooner

For sooner use in the coming weeks will be today’s sowings of lettuce, cucumber, and summer squash. I like lettuce but lettuce doesn’t like hot weather and longs days. Those conditions cause leaves to turn bitter as plants send up flower stalks and go to seed. But if I sow a pinch of seeds in flats every couple of weeks, the transplanted lettuce can usually be harvested small, before it’s socked away enough energy and wherewithal to go to seed.

The cucumber transplants I’ll want on hand to replace cucumber plants that I set out a couple of weeks ago. After a few weeks those spring plantings invariably succumb to powdery mildew and cucumber beetles, which not only feed on the plants but also spread bacterial wilt disease. (Easy identification for bacterial wilt, besides a wilting plant, is the thread of bacterial ooze visible as you pull apart a cut stem.)
Cucumber seedlings
Summer squash plants also peter out during summer, mostly from, again, powdery mildew, and also from squash bugs and vine borers. If squash vines are covered with soil along their stems, roots will form at the nodes, and the plant will continue production. I’ve got to be careful in saving the older squash plants, though; it’s too easy to  have too much of this vegetable.
Squash vine borer damage

Memorial Day, Before, During, and After It

Here in the States, the traditional time to plant a vegetable garden, is for some reason, Memorial Day weekend. But that can’t be true from Oregon to Florida and from Maine to Arizona, with our wide variations in climate!

I did put tomatoes, peppers, and plenty of transplants in the ground here during Memorial Day weekend. But I already had sown seeds or transplants of peas, arugula, lettuce, kale, carrots, celeriac before that weekend. And, as I’ve written above, there’s plenty of planting to be done after that date. Memorial Day weekend is not a seminal date in my gardening calendar.

HOT KNOWLEDGE

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Between a Rock and a Hard Place

More knowledge makes for a better gardener. That’s what I had in mind with my most recent book, The Ever Curious Gardener, excerpted here:

With hot weather here today, and soon to be a regular occurance, I pity my plants. While I can jump into some cool water, sit in front of a fan, or at least duck into the shade, my plants are tethered in place no matter what the weather. And don’t think that plants enjoy searing sunlight. High temperatures cause plants to dry out and consume stored energy faster than it can be replenished. Stress begins at about 86 degrees Fahrenheit, with leaves beginning to cook at about 20 degrees above that.
Watering with hose
One recourse plants have in hot weather is to cool themselves by transpiring water. Transpiration, which is the loss of water from leaves, can cool a plant by about 5 degrees Fahrenheit. Over ninety percent of the water taken up by plants runs right through them, up into the air, exiting through little holes in the leaves, called stomates. Carbon dioxide and oxygen, the gases plants need to carry on photosynthesis, also pass in and out through the stomates.

All this is fine provided there is enough water in the ground. If not, stomates close, transpiration and photosynthesis stop, and the plant warms. Even if the soil is moist, stomates might close in midsummer around midday if leaves begin to jettison water faster than the roots can drink it in. This situation puts most plants in a bind. Should they open their pores so that photosynthesis can carry on to give them energy, but risk drying out, or should they close up their pores to conserve water, but suffer lack of energy?

CAM at work

Enter cacti and other succulents (all cacti are succulents—that is, plants with especially fleshy leaves or stems—but not all succulents are cacti): their fleshy stems and leaves can store water for long periods. After more than a year without a drop of water, my aloe plant’s leaves still look plump and happy.

Besides being able to store water in their stems and leaves, jade plants, aloes, cacti, purslane, and other succulents have another special trick, Crassulacean Acid Metabolism, for getting out of this conundrum.

Aloe plant

Aloe plant, more than a year without water!

They work the night shift, opening their pores only in darkness, when little water is lost, and latching onto carbon dioxide at night by incorporating it into malic acid, which is stored until the next day. Come daylight, the pores close up, conserving water, and the malic acid splits apart to release carbon dioxide within the plant, to be used, with sunlight, to make energy.

I’ve actually tasted the result of this trick in summer by nibbling a leaf of purslane—a common weed, sometimes cultivated—at night and then another one in the afternoon.
Purslane
Malic acid makes the night-harvested purslane more tart than the one harvested in daylight. Try it.

No CAM? How ‘Bout C4?

Another group of plants, called C4 plants, function efficiently at temperatures that have most other plants gasping for air and water. C4 plants capture carbon dioxide in malate, the ionic form of malic acid, which is a four-carbon molecule, rather than the three-carbon molecule by which most plants—which are “C3”—latch onto carbon.

The enzyme that drives the C4 reaction is so efficient that C4 plants do not have to keep their stomates open as much as do C3 plants. The C4 pathway also does its best work at temperatures that would eventually kill a C3 plant, and cells involved in the various steps are partitioned within the leaf for greatest efficiency.

C4 plants are indigenous to parched climates, but not uncommon visitors in our gardens. Corn is a C4 plant. (Cool climate grains such as wheat, rye, and oats, are C3 plants.)
Tall corn plant
Looking at my lawn, I see another C4 plant. Hot, dry weather in August drives Kentucky bluegrass, a C3 grass, into dormancy. Not so for crabgrass, a C4 plant, which remains happily green.

I also find some other C4 plants, in addition to corn, in my garden. As many vegetables and flowers flag, all of a sudden lambsquarters and pigweed, both C4 weeds (or vegetables, for those who like to eat them), appear as lush as spinach in spring.

Gardener’s Assistance

Can I do anything to help out my plants in hot weather? Keeping the garden watered helps. (Ways to apply water and how much is needed are all-important, and topics unto themselves.)

Sprinkling or misting plants could keep them cool without their having to pull water up from the soil. But the thirty gallons of water that runs up through a tomato plant in a season, or the fifty gallons that flows through a corn plant, is for more than just cooling these plants. It also carries dissolved minerals from the soil into the plant. So it’s debatable how well a plant would grow with too much misting. And besides, wet plants are predisposed to disease.

A better alternative to sprinkling plants is to grow plants adapted to the climate and the season. My lettuce, spinach, peas, and radishes are doing fine now; despite today’s heat, it’s not really all that hot — yet. And nights are still cool. Mostly, I avoid growing these cool weather plants in summer. Except that I like my lettuce salads, so I extend its season by growing it in the shade beneath trellised cucumbers.
Lettuce & trellised cukes}
Fortunately, tomatoes, cucumbers, peppers, melons, and squashes, although they are neither cacti nor C4 plants, can take quite a bit of heat. They have very deep roots.