Archives for posts with tag: soil testing

It would be hard to tell from this blog (because I have posted so few real-time entries since mid-fall, 2014) but I decided not to send any soil out for testing this year (well, technically speaking, last year).

During the previous three seasons (2011, 2012, and 2013), I collected soil samples in late September or October (see October 19, 2013, part 2 for the most recent account) and sent them off to the Rutgers Soil Testing Laboratory. Two weeks after that, the lab sent me via e-mail me a report of our soil’s properties (see February 14, 2014 for discussion of the October, 2013 results).

It was a worthwhile endeavor—information is power, and all that—and we made some adjustments that I am sure were of benefit to the vegetables. Probably the most significant factor that the tests brought to our attention was soil pH. Initially, it was too high and the following year (2012), we added Sulfur to bring it down.

But after that first year, we did not learn anything new. Our soil’s pH has stabilized within the optimal range and both the macro- and micronutrient levels have remained constant. The soil appears to have reached a healthy equilibrium and as a result, there have been no recommendations for change. And as they say, if it ain’t broke, don’t fix it.

This year, the vegetable plants themselves are telling me everything I need to know. Almost all are very happy so the soil must be okay.

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More snow yesterday—a lot more snow—means that it is still too early to be thinking about starting any work on the garden outside.  At this rate of snowstorms, we won’t be digging out until March.

That is just as well because there are still a few items from last year to recap.  Most notably, there are the results of the soil testing that arrived at the end of October (2013) but which I have not had a chance to discuss.

Based on the previous year’s testing, I was not expecting any startling new information for the east and west planters (see October 19, 2013, part 2).  Sure enough, the reports confirmed my expectations.  The all-important pH of the soil remains within the sweet spot (6.20 to 6.80) for vegetable gardens with the east planter at 6.57 and the west planter a tad more acidic at 6.23.

Interestingly, the soil pH of the east planter increased slightly (from 6.31 in 2012) while the soil pH of the west planter decreased (it was 6.78 in 2012).  The soil in the east planter is now squarely within the preferred range but the soil in the west planter is bouncing from endpoint to endpoint.  Both are perfectly fine, however, and we will not have to make pH adjustment to either.

Similarly, the macro- (Ca, K, Mg and P) and micronutrient (B, Cu, Fe, Mn and Zn) concentrations in the east and west planters are close to each other, a result, I think, of at least three factors.  First, we treat the planters identically; neither has received any amendments (other than a top dressing of compost at the beginning of the season) or more fertilizer than the other.

Second, we have been rotating crops back and forth between the planters.  Therefore, their soils have been depleted (or replenished) by more or less the same amount.  Third, the age of the soil in each planter is more than two years.  I assume that given their consistent treatment, both soils are converging on the same steady state.

For the most part, the micronutrient levels in the west planter decreased when compared to last year (i.e., 2012).  This is not too surprising, again considering that we don’t heavily fertilize or otherwise modify our soil during the growing season (I think of it as time smoothing the soil’s rough edges).  Micronutrient levels in the east planter are mostly the same as 2012 (its soil is older and smoother).

What I didn’t expect is that in both planters, the concentration of Calcium increased by almost 50 percent.  We did not add lime, bone meal or any other source of the micronutrient so I have no idea from where the additional Calcium comes.

So much for the well-established planters.  On to the ground level soil, where we planted squash and cucumbers last season.

For starters, the pH of this soil is too high at 7.10 (the soil is slightly alkaline).  We’ve learned from both of the growing seasons prior to last that this can have a very detrimental effect on plant performance.  And I learned from this year’s experiments with seed starting mix that the culprit is probably not the very acidic peat moss, of which the ground level soil is roughly half.  The other half is compost (mainly cow manure) which tends to be more alkaline.

When we dig new pits for the squash and cucumbers this year, we will have to increase the proportion of peat moss to manure and perhaps add some elemental Sulfur to bring the pH down.  Otherwise, the ground soil profile resembles that of the planters.  The macro- and micronutrient concentrations are very close, including—somewhat mysteriously—the high concentration of Calcium.

This is a bit ironic because the summer squash plants experienced a high rate of blossom end rot last season, a condition that is usually associated with Calcium deficiency.  I think this is what the testing lab was alluding to when they called me in the fall (see October 24, 2013).  The testing methods based on acid extraction indicate a high concentration of Calcium but it is not, apparently, in a form that plants can readily use.  I’ll have to look into this one further.

The reports list lots of numbers, not all of them obviously meaningful.  So, what does it all mean?  The bottom line is that our planters’ soil is doing fine and that with minor modification the soil in the ground will come into line as well.  That’s good—if not exciting—news.

I’m happy to report that the 2014 growing season is officially under way.

In our garden, anyway.  Having assembled all of the necessary parts, I found some time this afternoon to sow seeds for the herbs.

As a first step, I washed the mixing tub, seed tray and trowel with a mild bleach solution.  All of these items were used last year and have been stored in the basement since.  The exposure to outside elements is high and given the dark and damp conditions down here, the potential for mold and harmful bacteria is great.

Then, I mixed up a batch of seed starting medium.  I measured out quantities of peat moss, vermiculite and perlite (in a 2:1:1 ratio) to equal a half gallon of dry volume and dumped them into the tub.  The lime I purchased is pelletized so I used a mortar and pestle to pulverize it into smaller particles.  A quarter teaspoon per gallon—an eighth of a teaspoon for this batch—seemed much too small; I used a teaspoon.  To be more accurate, I would need to know the pH I was starting with.

Using a spray bottle, I moistened the mix and stirred it with the trowel.  Peat moss is extremely dry and perlite can absorb a lot of water so I had to repeat this process for several cycles.  When the moisture content seemed right—damp but not soggy—I spooned the mix into a half seed tray (that’s 36 compartments) and tamped it in lightly.  It turns out that half a gallon of seed starting mix is just the right amount.

Next came the seeds.  We will be planting basil again this year (last year’s did extremely well) along with the herbs we purchased seeds for last year but never managed to plant:  rosemary, thyme, oregano, spearmint and sage.  Because most herb seeds are very small, I used tweezers to drop one or two seeds into a shallow hole (formed using a pencil as a dibble) in each compartment.

After covering the seeds with a pinch of mix (the recommended sowing depth for herbs is only 1/4 to 1/2 of an inch), I gently sprayed the tray with water until it ran out of the bottom.  For most of the herbs, this will be the only water they get until they germinate and emerge from the soil 10 days (or, in the case of the rosemary, 28 days) from now.  I set the covered tray atop a heating pad on a shelf of the seed starting apparatus, turned on the pad and fluorescent light and made sure that the timer was properly set.

Like all seed sowing, starting the herbs is an act of faith.  This is especially true for the oregano and spearmint whose seeds are teeny-tiny (they are packaged in small zip-top plastic bags within their paper seed packet).  I can’t be sure whether any seeds actually made it into the soil or from which tray compartments they will sprout.

But I firmly believe that they will and I will be thrilled when they do.

At breakfast last Saturday morning (pancakes and eggs at our favorite local joint), we started in on early planning for this year’s garden.  The first thing we concluded is that we are not really early.  By some reckonings, we should have sowed seeds for thyme last month and could be starting other herbs right now.  The second thing we concluded is that, once again, we are behind schedule.

Luckily, the choices of what to plant this year were relatively easy decisions even though a fair amount of thought went into each one.  We started with the list of plants we grew last year and then applied a few different criteria to assess their success.

The most important criterion for each vegetable is our answer to the question, did we like it?  It doesn’t matter how well it grew or how much it produced if, at the end of the day, we won’t eat it.  Of last year’s crops—those that actually yielded fruit—the only one that did not absolutely thrill us was the Aunt Ruby’s German Green tomatoes.  They were not bad, per se, but they didn’t leave us wanting for more.  Consequently, we will not grow them again this year.

There was one plant whose fruit we could not taste.  The Delicata winter squash did set fruit—several of them—but was not able to develop any of them to maturity.  And that leads to the next criterion, performance.  Plants that did not thrive last year may not be suited to our particular microclimate.  Then again, we may not have given them what they needed, either.

So, what besides the Delicata did not perform?  Well, the Kabocha winter squash produced only one specimen by the end of the year and it was a small one at that.  That’s two strikes against the winter squashes and based on this meager showing, I was tempted to say that we should try other varieties this year or skip them altogether.

However, roasted with a little olive oil and salt, the Kabocha squash was absolutely delicious.  It passed the first criteria with flying colors even though it showed weakly on the second.  Similarly, although we were not able to sample the produce of our Delicata, it is one of my favorite varieties (we often buy it at the farmers’ market).  Therefore, we will try the Delicata and Kabocha squashes again.

The next criterion then is, why did these vegetables underperform?  My best guess is that we underfed them.  I haven’t reported on last year’s testing yet (look for a future posting) but soil properties are a definite suspect.  The areas we planted with the squash were newly formed last year and have not had much chance to stabilize.  This spring, we will probably need to enrich their soil and fertilize them more frequently.

The same could be true of the summer squashes—both the yellow crookneck and pale green zucchini—and the cucumbers—one a pickling variant and the other a slicing type—all of which we planted in more or less the same area (the ground surrounding the planters) and with roughly the same soil (equal parts of compost and peat moss).

Despite these similarities, however, their performance was quite different.  Three of the four summer squash vines were hugely productive (especially the alpha crookneck; see August 6, 2013) whereas the cucumbers produced only a modest quantity of fruit before fading away in mid-summer.  Two other factors could account for the differences.

First, the amount of soil we introduced for the cucumbers was much, much less than for the squashes.  This is partly because of their location between the pool fence and planters but mostly because the cucumbers were the last seedlings we planted.  By that time, we were tired!  Our native soil is rocky and very difficult to dig but we will have to face up to doing more of it this year.  Adding to and amending the soil will be an early spring chore.

Second, the cucumbers were stricken hard by powdery mildew and once afflicted, perished rapidly.  It is not clear (and probably never will be) whether this was due to their undernourished state or simply because the varieties we planted are more susceptible than others to powdery mildew.  The squashes, on the other hand, seem better able to continue to produce after contracting the disease.  Each of the squash vines was still setting fruit into the fall.

Both of these are factors we can mitigate—or try to mitigate, anyway—and so we will plant both types of summer squash and both types of cucumbers again.  To help control the powdery mildew (which is endemic in the northeast), we will plant in new locations.  I will also arm myself with a spray bottle full of baking soda solution which I will apply early and often.  With diligence—and luck—we will have more squash and cucumbers than we can eat this year.

Greetings from the future.

What’s that, you say?  Today is January 6, 2014 so how can this post be from the future?

Well, it may be January 6, 2014 in the real world but in my blog’s timeline, the date is currently October 24, 2013 (my most recent post).  In fact, the garden engineer calendar has been stuck in October for quite some time now.  This is mainly because in the last two months, there have been many things to which to chose to say “yes” or “no” to.  With the garden fully dormant (spoiler alert:  the growing season has ended!), I elected to say “no” to it and its blog and “yes” to some of those other things.

But now that the holiday season has passed (another spoiler alert:  Thanksgiving and Christmas have already occurred and were the best ever!), I have time to loop back and fill in some of the missing posts from the end of 2013.  My brother made the excellent suggestion that I simply do a single, catch-up summary but I’m afraid that I am much too literal- and serial-minded to be able to do that.  Besides, some of the posts were already (mostly) written.

Instead, over the next week or two I will continue the chronology that garden engineer has been following from the start, including only those posts that pertain to actual events during year’s end.  For topics that are less temporally fixed, e.g., season recap, soil testing results, planning for this—I mean next—maybe I do mean this—year (time travel is difficult), I will wait until after I have caught back up to the present day.  With luck, that will be soon.

For those readers who feel that 2013 ended too quickly, this might be a welcome extension of the fall and holiday seasons.  Others may wish to skip ahead.

So Happy New Year (when you get here).  Until then (to paraphrase Doc Brown), “Back to the Past!”

After returning home from running errands this afternoon, I was surprised to find a voicemail message from the soil testing laboratory.  This is the third year I’ve sent them soil for analysis and I did nothing different this year compared to the previous two years.  What could the issue be?

I gave the lab a call back and learned that they were concerned that the tests I requested might not be appropriate for our soil.  Based on a brief visual assessment of the soil samples and their labels (“East Planter”, “West Planter”, “Ground Level”), and without checking the type of planting for which the soils would be used (as I had indicated on the back of the soil test questionnaire), the lab scientist thought that perhaps I worked for a mall and was checking the soil from its indoor flower beds.  I’m not sure whether to be flattered (or not).

It turns out that the basic soil tests I commissioned are intended for mineral-based soils and use acids to extract the nutrients of interest.   This method is efficient and quick and yields reliable results for total nutrient content.  However, for soils that have very high concentrations of nutrients in mineral form, the observed values may not represent how much of the nutrients are actually available to plants.  For example, a clod of partially decomposed ore may be rich in iron but spinach still won’t grow well in it.

Alternatively, for compost and other soils rich in organic matter, extraction by water solubility is usually employed.  Apparently, this method takes longer and is somehow more complicated (I infer, because it costs much more) but produces values that are closer to what is readily available to a plant’s roots.  I explained our soil’s situation—it is used for a vegetable garden—its composition—it is a mix of compost, peat moss and native soil—and its history—she looked up the previous years’ reports—and weighing this information, she decided the basic tests would be okay.

The soil scientist said that many people are (and here she groped for a politically appropriate word) enthusiastic about adding organic matter to their soil, by which I believe she meant to imply that they add too much.  Looking at our previous reports, however, she saw that although some of our nutrient levels are high (“above optimum” is the lab’s term), the values are not off the charts.  I think she concluded that the total and available concentrations of nutrients in our soil should not be too different.

Looking more closely at our previous analysis results, she liked that our soil pH was in the green zone (6.20 to 6.80) last year and noticed that in our first year (the east planter only, in 2011), our pH was high.  I reported that based on the report, we adjusted the pH by adding elemental Sulfur and that was probably why we were at the proper acidity by the end of the 2012 season.  She was happy to hear that someone actually followed their recommendations.

The lab will start the soil testing tomorrow and I hope to hear back from them next week.

It’s that time of year again (past time, actually):  Time to send the soil out for testing.

Why is it that time?  Because the growing season is over and the soil is as depleted as it will get this year.  Now is the time to add supplements or nutrients that the soil may need before the new season starts in spring.  And I won’t know what to add without an assessment of what is—or is not—there.  Also, the planters are (almost) bare so it is convenient to take samples.

Testing is becoming less critical for the east planter, which has just completed its third year of service.  Its soil needed adjustment after the first year (to increase its acidity) but received no amendments last year.  We did add a small amount of compost (to bring the soil surface higher) and may do so again this year.  Otherwise, I don’t expect that the soil’s properties have changed much.

Similarly, the soil in the west planter was nearly on the mark in terms of pH and nutrient concentrations, as evidenced by its first soil testing last year (see October 4, 2012).  It received the same treatment as the east planter (a minor infusion of compost) and in conjunction with the solid performance of this year’s crops, is unlikely to need any modifications.

The condition of the newest soil in the garden, the mounds where we planted the squashes and cucumbers, is another matter entirely.  We were not particularly careful in designing this soil and simply mixed together roughly equal parts of compost and peat moss.  It looked right and was good enough but apparently only just so.  While the summer squashes performed adequately (especially the yellow crookneck), the winter squashes and cucumbers did poorly (in fact, only one Kabocha and none of the Delicata squashes reached maturity).

Clearly, there is something missing from (or otherwise not quite right with) this soil.  Testing should help uncover what that is.

As in previous years, for each of the planters and the mounds, I dug soil from four locations, mixed it together and dumped it into a labeled zip-top bag.  I slipped each baggie into a larger one (to contain possible spillage) and packed the three sacks into a box for shipping.  To the box I added the testing lab’s forms (one for each sample) and a check to cover expenses.

Next week, I’ll send them to New Jersey and in another week to 10 days, we should have the results.

It’s a happy time of year in the garden.  Everyone is growing with vigor and strength (every one of the vegetables, that is).

Well, almost everyone.  One of the cucumber vines is showing the unmistakable signs of bacterial wilt, having been infected (I presume) by the striped cucumber beetles who arrived in the garden only recently.  The upper third of the vine is completely and irreversibly shriveled.  I snipped off the afflicted section and will see whether the condition spreads to the remainder of the plant.  Based on experience, I’m fairly sure that it will but as my father used to say, hope springs eternal (he usually said this about our always-hungry cat).

Bacterial wilt aside, the cucumbers have not been particularly successful this year.  We are very happy with the varieties—they are the tastiest and have the silkiest texture of any we have ever grown—but the vines are small and weak and there has not been an abundance of fruit.  Whether this is due to the particular cultivars, too little or too much water, the soil (very likely; we dug only small pits for the seedlings), or—who knows?—sun spots is not clear.  It is nearly time to take soil samples for testing and perhaps that will shed some light.

What I’ve learned about beets:  First, they need less Nitrogen than flowering plants and relatively low soil pH (i.e., slight acidity).  Our soil is at the high end (6.78) of the preferred range (6.2 to 7.0), based on last fall’s soil report (see October 4, 2012), and I infer that our Nitrogen level is also high (last year’s report recommended adding only nominal amounts).

Second, beet seeds are clustered.  What looks outwardly like a single seed is actually a seedball consisting of three or four seeds held together by an outer layer.  This redundancy helps insure that the plants successfully reproduce—each seedball is three or four times more likely to produce a new plant—but for the gardener, it can be too much of a good thing.  Under favorable conditions, all of the seeds will germinate and if all of the seedlings are left to mature, the result will be plants that are so closely spaced that there is no room for the roots to develop.  Even with careful sowing, therefore, thinning will be required.

Third, while the beet greens can grow quite quickly, the beet roots will sometimes grow very slowly.  This condition arises in part from the higher Nitrogen concentration in the soil—which promotes vegetative growth—and is dependent on temperature as well.  We had a cool spring during which the beet seeds rapidly germinated and produced lovely heads of dark green leaves.

Then, before the roots could catch up, the weather turned warm and the beets’ development slowed.  We kept them well hydrated, so they were not permanently damaged by the heat, but their growth was stunted.  I will do some research into how to minimize the Nitrogen effect (it is not clear what nutrients would promote root growth) and with luck, next year’s beet roots will develop earlier, before the hot weather arrives.

Fourth, beet roots can go a long time unharvested, even in high heat, with no detrimental effects.  We discovered this when we pulled out the first row (see July 28, 2013) and found the beets to be in good condition even though they had been in the ground for months.  It makes sense, botanically:  The roots store solar energy collected during the beets’ first year of growth in order to produce flowers and seeds during their second year.  It makes beets a good choice for busy people.  Unlike more delicate vegetables like tomatoes, which will rot if left unpicked for too long, beets will wait patiently in the garden with no ill effects until their grower is ready for them.

What I already knew about beets:  They are absolutely delicious, especially when roasted, which intensifies their flavor.  And the greens might be more delicious than the roots (they are certainly more nutritious).  Beet greens make a fine addition to salads when they are young and hold up as well as, if not better than, spinach when sautéed.

We are still experiencing blossom end rot of the crookneck squash.  It is not affecting every fruit, however, and despite losing two or three potential squash, we were able to harvest two healthy ones.

At the same time, we also picked two of the Cavili zucchini.  These turn out to be a pale green variety (as opposed to the more typical dark green type) and are best picked small (about four inches in length).

Blossom end rot is caused by a deficiency of Calcium in the soil.  The soil in which our squash plants are growing should be rich in minerals but it is new, by which I mean it has not been tested; we do not know its balance of macro- and micronutrients.  It could easily be short on Calcium or perhaps overly acidic.

We have a friend who swears by bone meal.  Whenever she plants a squash or tomato plant, she sprinkles a handful of it into the bottom of the hole.  That way, she knows that the plant will have a ready source of Calcium.  We have rarely done this (based on the results of soil analysis and, admittedly, laziness).

We’ll keep an eye on the squash plants and if the end rot persists, will consider adding Calcium in some form (bone meal is slow so a liquid form may be more efficacious).