Category: Garden

Posts about gardening and related topics, such as canning and maybe other aspects of food preservation.

Post G22-020, seedless cucumber germination rate.

 

 

 

This is a quick followup on my last gardening post, where I answered the question “where do seedless cucumber seeds come from?”.

The short answer is that most of them are first-generation hybrids.  Thus, seedless cucumbers seeds come from the fruit that results from crossing two carefully-chosen seeded cucumbers.  The resulting fruit has seeds, but those F1 seeds are then sterile, in the sense that the plant grown from that will not  produce viable seeds. Continue reading Post G22-020, seedless cucumber germination rate.

Post G22-019: Parthenocarpic Catch-22.

 

The question.

Recall Post G22-013, where I proposed to bypass last year’s troubles with cucumber beetles and squash vine borer by growing parthenocarpic varieties of both plants.  A parthenocarpic plant is one that produces fruit without fertilization, that is, without pollination.   No bees needed, which means I can grow them inside an insect-proof enclosure, excluding the bees along with the pests.

The resulting fruits are sterile and lack fully-developed seeds.

I have to admit, as I ordered up a few packs of seeds for various parthenocarpic cucumbers and squash, I did have this nagging little question:  How do they produce viable seeds from parthenocarpic plants?  Isn’t “seedless cucumber seeds” an oxymoron?

I stifled that question and ordered the seeds anyway.  The seeds I bought were offered by a presumably reputable seed merchant.  And I know that greenhouse-based farms produce plenty of produce from parthenocarpic varieties.  Didn’t seem like much of a risk.

That said, buying seeds for seedless cucumbers does seem like a bit of a Catch-22.  Or maybe a chicken and egg problem.  Perhaps my local nursery stocks the seedless cucumber seeds right next to the dehydrated water.

At the time of purchase, I noted a seemingly unusual percentage of purchasers’ comments complaining of low or no germination rate.  But you see comments like that on the sites of any seed vendor.  I chalked up the squawking to the relatively high cost per seed.  These parthenocarpic varieties seem to sell for anywhere between 25 cents and 50 cents per seed.  A poor germination rate is not much different from mulching your plants with ground-up dollar bills.

And now, of the 20 seeds planted (five different varieties, three cucumber, two squash), in peat pellets, exactly four seeds appear to have sprouted.  These are from two cucumber varieties.  All the rest of my new whiz-bang parthenocarpic seeds appear to be duds.

But is that normal?  And is it true that they failed to sprout, or is there some other explanation?  Because if that’s really the germination rate, I paid somewhere around $1.75 per viable seed.    For cucumbers and squash.  Which feels more akin to mulching your plants with $20 bills.

So that gets back to the main question of this post:  How, exactly, do seed vendors produce seeds for parthenocarpic varieties?  (Or, more simply, where do seedless cucumber seeds come from?) And is there usually a low germination rate for parthenocarpic varieties?

The answers.

As it turns out, there are several ways in which you can get viable seeds for “seedless” parthenocarpic plants.   But as far as I can tell, the most common parthenocarpic varieties are F1 (first-generation) hybrids.  So, by and large, you don’t get seedless cucumber seeds from seedless cucumbers.  You manufacture them by crossing two seeded varieties that generate the parthenocarpic (seedless) first-generation hybrid offspring.

Of the five varieties I planted, four of the five ( Diva Cucumber, Sweet Success Cucumber, Easy Pick Gold II squash, and Golden Glory squash) are either explicitly marketed as F1 hybrids, or simply as hybrids.

For those, there’s no fundamental reason they would have any lower germination rate than any other F1 hybrid.  These same varieties are planted by commercial farmers growing produce in greenhouses and poly tunnels.  Presumably, they wouldn’t put up with extremely low germination rates.

The sole exception to the F1 rule is Little Leaf cucumber.  As it turns out, that is an open-pollinated variety, not a hybrid.  But that’s also a gynoecious variety — that is, it produces all (or nearly all) female flowers.  Thus, you can get a Little Leaf cucumber with seeds, in the rare event that a male flower is produced that fertilizes one of the many female flowers.

So the upshot is that of the five seedless varieties I’ve chosen, four are F1 (first-generation) hybrids, so the seeds for them are actually produced by crossing two non-parthenocarpic varieties.   I don’t think they’ll produce seeds under any circumstances.  And the last one is seedless, but only because the plants are rarely fertilized owing to its gynoecious nature.  It’ll produce either seeded or seedless cucumbers, depending.

Now that I know how this works, I’ve done what I should have done from the start, and dissected the peat pellets that I planted these in.  Mystery solved: There are no seeds inside.  Plausibly, some birds came by and pecked the seeds out while I had these sitting outside.  So all I need to do is replant, and be a bit more careful, and I should be able to proceed according to plan.

I’ll report back on the actual (bird-free) germination rate in a couple of weeks.

Post G22-018, Sprawl method for tomatoes.

 

End-of-season edit:  When all is said and done, I won’t be doing the sprawl method again with full-sized tomatoes.  Maybe I planted these too closely, but I ended up with a tangled mass of vines, weighted down by the fruit.  A lot of tomatoes ended up rotting.  Either you can’t see them, or you can’t get to them, or they end up on the ground.  It’s a lot less effort to grow them, compared to staking them up, but you don’t get much in the end. 

Everything else here:  Cold-tolerant tomatoes, and electric fence as deer deterrent, gets two thumbs up.  I now plan on growing cold-tolerant (short-season) tomatoes every year.

I’m now in Phase III of my four-part tomato strategy for 2022.  I outlined that in  my first garden post of 2022 (G22-001).  It’s time for an update.  I’m posting it because otherwise I’ll never be able to recall how things went this season. Continue reading Post G22-018, Sprawl method for tomatoes.

Post G22-015: First test of tote-based food dehydrator, version 2

 

Construction details are given in Post G22-014.

Bottom line:  Works just fine if you ventilate it with a computer fan.  Leaving this outside on two consecutive chilly, dry, sunny days was adequate to get 1/4″ potato slices dry enough to snap crisply when bent.

It was a little cold yesterday for solar food dehydration, not expected to top 60F.  But it was sunny and dry.  And that was enough to let me test and refine my revised tote-based food dehydrator (Post G22-014).   This is nothing more than an under-bed plastic tote with a bit of radiant barrier insulation outside, some cheap cooling racks inside, and a few holes in the top connected to thin plastic pipe.

Continue reading Post G22-015: First test of tote-based food dehydrator, version 2

Post G22-014: Plastic tote food dehydrator, version 2: Construction.

 

Edit:  See Post G22-015. Skip the drying racks, just place the food directly on the floor of the tote.  Replace the ventilation “chimney” with a computer fan.  With those changes, two days in the sun produced perfectly dry potato slices.

Last fall I came up with what I hoped would be a cheap and simple solar food dryer capable of drying tomatoes in the humid climate of Virginia. Continue reading Post G22-014: Plastic tote food dehydrator, version 2: Construction.

Post #G22-013: Toward a theological and horticultural theory of parthenocarpic zucchini.

Edit 7/29/2022:  Read post G22-050 first.

Theological and horticultural background

A parthenocarpic plant is one that produces fruit without fertilization, that is, without pollination.  The resulting fruits are sterile and lack fully-developed seeds.

Without getting into the deeper theological aspects, the word derives from the Greek “parthenos”, meaning virgin.   And “carp”,  meaning to complain.  Thus,  the Parthenon is a temple to Athena, who was virgin who had few complaints.

(Technically, carp means seed.  So parthenocarp means “virgin seed”.  I like my version better.)

Of course, now that you know the word, examples crop up everywhere.  The banana is almost surely the most familiar example of a parthenocarpic fruit.  If you’ve ever wondered why bananas are seedless, now you know.  It’s due to their parthenocarpic nature.

Every parthenocarpic fruit is more-or-less seedless, but not every seedless fruit is parthenocarpic.  Some still require fertilization, they just don’t (or rarely) produce fully mature seeds.  Seedless watermelons fall into that category.  Unlike true parthenocarpic plants, seedless watermelons must be pollinated to bear fruit.  The term of art there is “stenospermocarpic”, which seems to be Greek for narrow fertilized seeds.

This is also not to be confused with plants that require pollination, but not pollinators.  Those include plants that are “wind pollinated” (like most cereal grains), and plants that may be “self-pollinating” due to perfect flowers containing both male and female parts, so that simply shaking the flower may sometimes pollinate it.  (This is the source of the electric toothbrush hack for ensuring good tomato pollination.)

Parthenocarpic cucumbers and summer squash.

Greenhouse and poly-tunnel farmers provide the commercial demand for parthenocarpic varieties of common garden plants such as cucumbers and squash.  In those enclosed environments, without bees, those crops would otherwise have to be pollinated by hand.  That’s an obviously labor-intensive step, and may be a practical impossibility for crops grown under low “hoop house” type row covers.

Several different varieties of parthenocarpic cucumbers and squash are available to the U.S. home gardener. I’ve been compiling a list, but I’ve limited it to the small subset of fruits that appear more-or-less identical to their seeded, pollination-requiring cousins.  The subset of interest to me includes:

Cucumbers:  H-19 Little Leaf, Corintino, Dive, Excelsior, Piccolino, Quirk

Squash: Venus, Part(h)enon, Burpee’s Sure Thing, Defender, Duntoo, Dunja, Cavili, Golden Glory.

(Parthenon or Partenon, sure.  But Venus?  Singularly inappropriate.)

As far as I can tell, these are exclusively F1 (first-generation) hybrids.  (Because, seedless, right?)  So if you will only grown heirloom plants, or those from which seeds can be saved, this is not for you.

To determine which varieties to grow I will apply the Tomato Paralysis cure from Post G22-001.  List in hand, I’ll cruise the seed racks at my local garden center and grow whichever of those they carry locally.

As a bonus, I can have my very own guilt-free arena of death.

I ended up here because I had such a dismal time trying to grow cucumbers and summer squash for the last couple of years.

The squash vine borer is present in this area (Virginia Zone 7) for a couple of months.  That is, more-or-less for the entire squash growing season.  If you restrict yourself to relatively short-lived pesticides (I used spinosad), controlling it requires careful spraying at five-to-seven day intervals. See Post #G27, A Treatise on the Squash Vine Borer.

The cucumber beetle was essentially absent from my first year of gardening, and I had a bounteous crop of cukes.  But by my second year I had built up an unstoppable population of them, and got almost no cucumbers whatsoever.  I never found a way to control the cucumber beetle that a) worked and b) was acceptable to me, in terms of environmental impact.

The damned things are like vampires:  All it takes is one bite.  Cucumber beetles spread bacterial wilt.  So it’s not the actual leaf and blossom damage from their feeding that matters.  It’s that any feeding at all infects the plant and kills it.  As far as I can tell, a) once bacterial wilt starts, it’s just a short while until the entire cucumber plant is dead, and b) “wilt-resistant” cucumber varieties aren’t, they end up just as dead as non-resistant varieties.

But if I don’t need pollinators, I can grow summer squash and cucumbers under insect netting/row cover.  In theory, if I can sterilize the soil under the plants (with a neem oil soil drench, perhaps), and keep a bug-proof enclosure over the plants, I can physically prevent those pests from reaching the plants.  And yet have a crop, because barring the bees entry does these plants no harm.

I’ve been hesitant to try this.  Not just because it seems like a lot of work to set up, and a lot of hassle to maintain.  But because of the “vampire” nature of cucumber beetles.  It’s not their feeding that matters directly, it’s the disease they carry.  If a single beetle breaches the defensive perimeter, it’s game over for the cucumbers.  Do I really think I can (e.g.) lift the cover off to pick the ripe fruit and set it back again without letting in a single cucumber beetle?

It seemed to be a fairly non-robust setup.  I understand that insect netting can greatly reduce insect damage.  But because of the nature of the beast — bacterial wilt — I really need to eliminate it entirely.  If the endpoint is going to be a bed of deceased cucumber plants, I know ways to achieve that with a lot less effort.

But if the bees and butterflies can’t get in … then nothing bars me from making that enclosed garden bed an arena of death.  All of those highly-effective (i.e., deadly) pesticides that I normally won’t touch due to bee toxicity are now back on the table.  Subject to some constraints, nothing need stop me from hosing the bed down with (e.g.) pyrethrins on a regular basis (subject to controlling runoff).  This means I can install a secondary, chemical line of defense beneath the primary (physical) barrier.   If need be.

I’m looking for parthenocarpic, not carcinogenic.  So it’s not like any pesticide is fair game.  But cheap, short-lived and effective organics like pyrethrins would seem to be plausible.  Once I screen in the bed, I no longer have to worry about killing off my local bees and butterflies.  More-or-less any bug that gets through the outer defenses is fair game.

Conclusion

Anything worth doing is worth over-doing.  Given how much hassle it’s likely to be to do this at all, I think I’ll go for more, rather than less.

My plan is to dedicate one entire raised bed to parthenocarpic cucumbers and squash.  Roughly 4′ x 16′ or so.

Plausibly the major expense will be for the requisite statue of Athena, so that I may dedicate my parthenocarpic garden appropriately.  And some large-economy-sized Bucket-o’-Death, to ensure that any bug making it past the cover will die ASAP.

Otherwise, for me, this requires no investment in materials.  I already own a more-than-lifetime supply of thin floating row cover.  As well as a pile of loose PVC pipe and fittings, which is to adults what Tinker-Toys are to kids.

A year ago, I didn’t even know that such a thing as parthenocarpic squash existed.  This year, I’m going to grow a bed of it.   I’ll let you know how it turns out.

 

Post G22-011: Canning lids, from shortage to wide-mouth surcharge.

Above:  Used Ball lids.  The one on the left clearly shows the groove left by the canning jar.  The one on the right was boiled for 20 minutes, which flattened that groove considerably.  I picked up this tip boiling lids if you plan to re-use them from the blog A Traditional Life.

One of the many U.S. shortages that occurred during  the COVID-19 pandemic was a shortage of lids for use in home canning.  I’ve posted extensively on that here. Continue reading Post G22-011: Canning lids, from shortage to wide-mouth surcharge.