Archives for posts with tag: soil temperature

You can tell that we’ve finally passed the point at which cold nights can be expected; there is a freeze watch in effect for tonight. I’m not too worried—the National Weather Service does not actually predict sub-freezing temperatures—but I will cover the east planter with black plastic sheeting just to be safe.

The radishes, always first off the starting block, made their appearance three days ago and the Sugar Snap peas, not to be left behind, started to peek out from the soil a day later. There are now seedlings to protect and the root vegetables are particularly susceptible.

With the trellis in place, I cannot fully cover the peas, but I don’t think it is necessary. The pea shoots are quite hardy and even without completely enclosing the planter, the sheeting will capture the heat that the garden acquired during the day.

I wonder what date the National Weather Service uses for last frost in our area? I conservatively use May 5, which has a 90 percent confidence level (i.e., there is only a 10 percent chance that the temperature will fall below freezing). Apparently, the NWS uses an earlier date.

I suspect that they use a lower confidence level, probably at a 50 percent chance of exceedance. Their date—whatever it might be—is less conservative from a freezing temperatures point of view but more conservative from a freeze warning point of view (i.e., its use will likely generate more warnings). Given that the NWS is in the business of forecasting the weather and not gardening, this makes perfect sense.

Mother Nature continues to be a bit confused about what season it is.

After a glorious weekend when temperatures reached through the 70s and into the 80s, we awoke this morning to a one-inch-thick layer of snow and ice which fell overnight.

Like the winter storms before it, the snowfall cloaked the still-leafless trees in a shroud of white. It has been long enough since the last one that I can again appreciate the beauty.

Sadly, however, I could not escape the need to sweep the walk and scrape the cars, tasks made more difficult by the persistent cold temperatures. That I do not appreciate. Nonetheless, it is forecast that the day will warm to above freezing and the snow should soon melt.

The planters are also blanketed by snow but I’m not worried about the seeds we planted on Sunday (see April 13, 2014). Probably nothing much has happened beneath the soil’s surface. The seeds will pause whatever they were doing and will resume when the soil heats up again. In effect, it will be as if the seeds were planted today.

Warning:  Insect photos below.


While we were in the yard watching the tree work, we sighted more evidence of the 17-year cicadas.  As most people living in the northeast know, Brood II will be making an appearance this spring and will be with us for the entire summer and into the fall.  The unusually cool weather has delayed their emergence from the soil, a process that is driven by soil temperature.

Things are slowly warming up, finally, and the little critters are starting to make their way to the surface.  When they get here, the first thing they do is slough off the skin they’ve been wearing for the last 17 years.  They crawl out onto a tree branch or flower stem and as they are warmed by the sun, burst through the old skin straight down the middle of their backs.

They then climb out and drop to the ground, leaving the old skins behind as translucent ghosts of their former selves.  Eventually they dry out, their wings become functional and they fly off to find food and mates.  The males will be singing their low-pitched serenades all summer and the females will click-click-click at their chosen suitors.  I hope they find their eventual lovemaking worth the wait.

Not shown on our Seed Sowing Calendar (see March 23, 2013) are the additional sowing dates for root crops such as carrots, turnips, beets and radishes.  We planted the first two rows of them three weeks ago (see March 31, 2013, part 2) and today, I planted two more.

I started by digging out the mulch to expose the soil surface.  It wasn’t easy—the mulch is thick and matted—but when I got there, I was happy to find the soil warm and moist.  The mulch has been doing its job.

I followed the same pattern of planting, sowing first a row shared by carrots (east) and radishes (west) and then a row with turnips (east) neighboring beets (west).  The only difference is that I swapped the locations of the Chioggia and Touchstone Gold beets.  The colors of their stems match the color of the beets and will add to the visual aesthetic of the planter when the plants get closer to maturity.

Some people use tweezers to place seeds and as I was sowing the turnips, I could understand why.  Turnip seeds are almost identical to poppy seeds and are very difficult to sow evenly.  I take a pinch between my thumb and forefinger and then roll them back and forth over the row in a motion similar to salting a hamburger.  It works fine but undoubtedly there will be clumps of seedlings when the seeds sprout.

The carrot seeds are also quite small and I used the same method for them.  The radish and beet seeds, on the other hand, are larger—about the size of ball bearings—and much easier to place, one at a time, with about an inch between them.  We’ll see how well I did when they germinate.

There is still space for one more row which we will plant with carrots and radishes in early May (it’s hard to believe that it’s only a few weeks away).  The west planter is almost full while the east planter looks oddly empty in comparison.  It will remain that way until we plant the lettuces (due this week but probably not happening until next week).  Then, at the end of May (if all goes well), the east planter will become suddenly crowded when we transplant the seedlings that are growing inside.

On Wednesday, both varieties of cucumber started to sprout in their warm and cozy seed tray.  Then, yesterday morning, the squash seedlings made their way into the world.  By this morning, almost all of the cucumber and squash seeds had not only germinated but had exploded to a height of an inch or more.  The seedlings are much larger and more robust in appearance than any of the other vegetables we have planted so far.

After only a short experience with starting seeds indoors, we have already learned that all of the vegetable seeds enjoy warm temperature and need it to expedite their germination.  Without the heating pad, relying on ambient heat alone, nothing sprouted.  With the heating pad—even just a few hours per day—all of the seeds practically leapt out of the soil.  If this experiment proves successful, we will definitely consider procuring heating pads dedicated to seed starting use.

Okay, so we’ve decided to start seeds indoors.  It’s time to design a place to grow them.

We could buy a fancy, specially-designed rack with built-in lighting and heat but that can be very expensive.  Also, a pre-fabricated unit might not fit our needs exactly and would probably not be easy to modify.  Furthermore, it wouldn’t fit in with our do-it-yourself mindset regarding the garden and its appurtenances.  Instead, we’ll put one together from items we can buy at the Home Depot.

Most of the rigs we’ve seen in catalogs are based on free-standing shelf units so that’s where we started.  Because we do not have a lot of room in our basement, the unit will have to be of modest size and more vertical than horizontal.  Also, because there will be water (probably everywhere), the shelves should not be metal (which could rust) or wood (which might rot or get moldy); plastic would be the ideal material.  Browsing the Home Depot website, I found an 18” x 36”, 4-shelf unit for less than $20.  It is made of plastic and is listed as heavy-duty which sounds ideal.

The next component of the seed growing apparatus is the lighting.  My first impulse was to do a search for “grow lights” to see what came up.  What I found was a bit shocking, pricewise.  At the low end there were fluorescent fixtures starting at $25 dollars for a single two-foot bulb and at the other end were LED grow lights starting at almost $200, again for a single bulb.  I need three 4-foot-long fixtures with at least two bulbs each making these alternatives much too expensive.

And from what I’ve read, ordinary fluorescent fixtures are just fine for bathing seeds and seedlings in cool, white light.Also, the fixtures do not need to be beautiful (even if they needn’t be ugly, either) so ornamental or otherwise decorative models are out.  Basic, utilitarian shop fixtures seem like a good choice and, sure enough, I was able to find a 4-foot, two-bulb unit for around $20.  This fixture is supported from two chains—spaced, fortuitously, at about three feet apart—which will allow us to adjust its height above the seedlings as they grow.  We’ll get three and at least six 32-watt T8 cool white bulbs (like batteries, they are seldom included).

We next turned our attention to the trays in which we will plant the seeds.  Again, there are a lot of designs available, many of them customized for the purpose.  For instance, some of the trays are compartmentalized to make transplanting easier.  The compartments come in different sizes as well with the smaller ones being better for sowing seeds.  The larger cells may be needed for potting up those seedlings that are not ready to go into the ground.

The compartmentalized trays seem like a good idea but I think they might be harder to fill with soil.  Instead, we will plan on simple, non-compartmentalized trays.  My search came up with a lightweight plastic model that is 11 inches by 22 inches in area and 2.5 inches in depth.  We can fit two per shelf and even though they will extend beyond the ends of the shelves, they will still be completely covered by the light fixtures.  We will need six trays.  If we need to pot up, we will look at possible alternatives at that time.

At least two companies sell trays with each compartment filled with a pellet of compressed seed starting mix; when moistened, the pellet expands to fill the compartment.  This is another good idea but it is much more expensive.  And eventually, we will need loose soil (for potting up) so why not start with it?  Our gardening books tell us that all we need is a balanced mixture of milled peat moss and fine vermiculite so we will buy some of each and mix it ourselves.  Or perhaps we’ll get lazy and buy something pre-mixed.

Some seed starting rigs include heating pads to keep the soil and seeds at the optimum temperature.  We could get one sized to fit our trays (8.5 inches by 20.5 inches); however, at $20 each, the cost for six ($120) would exceed the total cost of all of the other items combined.  To avoid this, we’ll locate the seedling rack in the warmest part of the basement, near the oil burner.  The thermostat is usually set at 55 degrees down there but adjacent to the furnace, it is easily 10 degrees warmer.

To help the soil retain its heat, we will get clear plastic bags in which to ensconce the trays.  The plastic will allow the light (and its warming radiation) to reach the soil surface while keeping in the heat (and moisture, for that matter).  To ensure that we are maintaining an appropriate temperature, we will also get a simple soil thermometer.  Speaking of moisture, we will get a spray bottle to gently water the soil and the seedlings when they emerge.

With potentially hundreds of seedlings—most of which will look nearly identical to each other—we will need to identify what we planted and where.  As a final component of our seed starting apparatus, we will buy row markers to keep everything straight.  Ideally, these will be something simple and cheap (e.g., popsicle sticks) and, preferably, re-useable (therefore, probably made of plastic).

We now have our shopping list.  Onwards to the Home Depot!  (Our local garden center does not open until March.)