Cover boards for wildlife (Six on Saturday #61–December 12, 2020)

Six on Saturday today is another garden project. This one adds wildlife habitat to your garden and provides the opportunity to see animals that are usually hidden from view.

1. Cover boards


A cover board is exactly what it sounds like: a wooden board or piece of sheet metal that is placed on the ground to provide habitat for small animals. They’re often used by herpetologists to attract reptiles and amphibians, but they also attract insects, spiders, and small mammals.

This past spring, the kids and I placed three cover boards–two wooden boards and one piece of corrugated metal siding–in likely spots around our property. Over the summer and autumn, we have checked the boards once every two weeks, which we think is a decent compromise between checking so often that animals are frightened away, and checking so infrequently that we miss things.

If you live in a place with venomous snakes, it’s a good idea to use a rake or snake hook to lift cover boards. Pull the board towards you, so that you will have the upright board between you and any disturbed snakes. If you find a small animal, take a few pictures and then carefully lower the cover board again. Gently move the little creature to one side first, and let it crawl back underneath after you have lowered the board. You don’t want to find its squashed corpse the next time you lift the board Wait a reasonable amount of time and then repeat. That’s all there is to it

The rest of my photos today are animals that we found under the boards.

2. Eastern narrowmouth toad (Gastrophryne carolinensis)


The first time we looked under the boards, we found a pair of eastern narrowmouth toads. These guys spend most of their lives hidden, and I have only seen a handful in the past twenty years. I previously posted about this species here.

3. Wolf spider (Genus? species?)

Maybe a Hogna species?

4. Eastern worm snake (Carphophis amoenus)


I have written about eastern worm snakes here.


5. Another worm snake ready to shed its skin


6. Marbled salamander (Ambystoma opacum)


See this old post for more about marbled salamanders.

As always, the Propagator is the host of Six on Saturday.  Head over there to see his Six for this week and find links to the blogs of other participants.

Tiny Dinosaurs (Six on Saturday #60–October 17, 2020)

Pollo and Kylling 2
Kylling and Pollo look for grubs in a rotten log.

For the past two years, Youngest Offspring has been arguing in favor of backyard chickens, and her long campaign has finally been successful. My garden project this summer was building a coop and run next to my greenhouse, and on September 24, three pullets from a local farm moved in.

1. The coop

The chicken “barn quilt” was painted by my wife. Access port for the nest box is visible at right.

Since we have never kept chickens before, it took us a long time to decide exactly what to do about a coop. We considered various prefabricated coops but eventually decided to build our own. I purchased plans for the Basic Coop from but modified them to make the coop slightly taller and 3′ x 4′ instead of 3′ x 3′. This made the materials somewhat more expensive, but should allow us to keep up to five birds.


2. The run


The run is about 10’ x 20’, half covered with transparent corrugated polycarbonate and half open to the elements. I built a rough perch from the trunk of a young black tupelo tree (Nyssa sylvatica) and threw in some rotten logs for scratching and grub hunting purposes.

3. Security

anti-predator apron around the perimeter of the run.

We decided not to allow the chickens free range in the garden, because of the danger from predators. The birds are basically Youngest Offspring’s pets, so we want to protect them as well as we can. Raccoons are probably the biggest threat, but other predators in our area include foxes, coyotes, dogs, cats, skunks, opossums, hawks, and owls. There’s an outside chance of weasels or bobcats, or perhaps a mink following the creek up from the Eno River. Rat snakes probably aren’t a threat to adult chickens, so I’m not worried about excluding them—we’ll just remove any egg raiders we find.

At night, the chickens are confined to the coop, which will hopefully exclude nocturnal predators. For maximum ventilation without sacrificing security, the coop has a ceiling of heavy galvanized hardware cloth topped with corrugated polycarbonate. The large cleanout door and small door connecting to the coop are both secured with swivel hasps. I use carabiners to “lock” the hasps at night, because they’re easier to remove than padlocks but hopefully will be too difficult for dexterous little raccoon paws

The sides of the run are welded wire fence, and the part that doesn’t have a roof is covered with chicken wire to keep out hawks. Around the perimeter, we placed a horizontal apron of the same fencing material. When hidden beneath mulch it will hopefully slow down any dogs or other diurnal predators that try to dig under the fence.

So, fingers crossed. I hope we haven’t set up a buffet with free chicken dinners.

4-6. The girls




Pollo (left) and Kylling

Hühnchen is supposed to be an Ameraucana, but the farm said it is possible she is an “Easter Egger” (Ameraucana hybrid). Pollo is a cuckoo Marans. Kylling is a Red Star. In November they will be joined by a barred Plymouth Rock and an Easter Egger. Youngest Offspring has reserved the names Frango and Kuritsa.

The Propagator is the host of Six on Saturday.  Head over there to see his Six for this week and find links to the blogs of other participants.

Six on Saturday #54 (May 2, 2020)

The last ten days or so have been warm enough at night that I have finally felt confident to start moving tropical plants out to their summer quarters. The hummingbirds also arrived about ten days ago, and I have seen the year’s first aerial dogfights around the feeders.  Horticulturally, we have entered the “great green interlude,” the period after the peak of spring bulb and azalea flowering, but before the blooming of the summer perennials.  Although the first roses are opening, and there are still a smattering of bulbs and orchids flowering, the predominant color in my garden is the green of fresh new leaves.

1. Gladiolus x byzantinus


A welcome splash of bright magenta comes from half a dozen Gladiolus x byzantinus bulbs that I received in a trade with a gardener in Texas last year.  This plant from southern Europe has been considered a synonym of G. communis, but Kew currently has it listed as a natural hybrid, G. dubius x G. italicus.  An old heirloom bulb in southern U.S. gardens, G. x byzantinus starts growing during the winter and blooms in spring, long before the hybrids derived from African species like G. dalenii.

2. Philadelphis inodorus (Appalachian mock orange, scentless mock orange) with unusual flowers

P. inodorus flowers with six petals

P. inodorus flowers typically have four petals, but this year I have a stem covered with six-petaled flowers.  The shrub originated as five or six seedlings that I grew in a single pot, so it is possible that the unusual flowers are produced by one of the seedlings, rather than by a single branch that has sported.  However, the plants are now inextricably tangled together, so the only way I’ll be able to propagate this weirdo (assuming it is stable) will be to root a cutting.

Typical P. inodorus flowers

3. Bletilla striata var. albescens


I purchased this orchid as Bletilla striata var. alba, but the flowers exhibit very faint lavender coloration on the labellum.  Therefore, it would seem to be var. albescens, rather than var. alba which should have pure white flowers.  It does not seem to be as vigorous as the typical colored variety, but I think it has its own delicate charm.

4. Phlox nivalis (trailing phlox, pine phlox)


Moss phlox, P. subulata, is often sold by local nurseries as a native plant, but it is primarily a species of the northeast and midwest.  In North Carolina, P. subulata is found only in a couple of counties in the mountainous west of the state.  The superficially similar Phlox that grows throughout the piedmont is P. nivalis. I grew this one from a small cutting collected in Durham County.

5.  A couple of sages


Above, Salvia officinalis (culinary sage) in our herb garden.  Below, Salvia lyrata (lyreleaf sage), a common spring wildflower/weed.  Unlike S. officinalis, which grows as a semi-woody shrub, S. lyrata has a rosette of soft leaves that look vaguely like a dandelion.  I find S. lyrata particularly difficult to photograph, because its flowers stick out in all directions.


6. New plant bench


Last weekend, I built a wooden bench to house my pachypodiums and some of my tropical bulbs during the summer.  The bench is 7′ long x 4′ wide x 2′ high (2.1 x 1.2 x 0.6 m) and is constructed from pressure-treated pine.  It occupies the space formerly used for growing tomatoes, necessitating a search for a new place to grow that crop, but it should reduce spilled gravel and water damage on our wooden deck.


The Propagator is the host of Six on Saturday.  Head over there to see his Six and find links to the blogs of other participants.

Hobby greenhouse: how and why


At this time of year there isn’t much going on in the outdoor portion of my garden, so most of my horticultural energies are focused on my greenhouse.  I thought it might be worth writing about how and why I built a greenhouse for growing orchids and other tropical plants, what worked well, what I would do differently if I had to do it again, and what I have learned from almost seventeen years of growing plants under glass polycarbonate.

1.  Why build a greenhouse?

If you have to ask, you probably aren’t an orchid grower.

My orchid hobby started in the usual manner, with a single plant purchased from a local garden center.  There are approximately 23,000 natural orchid species and more than 110,000 orchid hybrids registered with the Royal Horticultural Society, so the novice orchid grower soon becomes aware that there are a lot of really interesting plants he or she could be growing.  Within a few months I had half a dozen orchids growing on a desk in the living room of my little student apartment.

orchids 1993 2
So it begins.  A few orchids and other plants on a desk, winter 1992/1993

I bought a book to figure out why some of my plants weren’t doing very well.  The book had lots of useful advice and the addresses of several mail order nurseries at the back. I joined a local orchid society.  The society had raffles and silent auctions and speakers who brought plants to sell.

Based on the advice in the book, I moved the plants closer to the window and added a fluorescent light.  And added more plants, of course.

orchids 1994 2

A year later, I had added another light and doubled the growing area.

orchids 1995 2

When the growing area was full again, I built a two-tier light stand.  Then I added a second one.  By 2001, I had two light stands in a spare room, and in addition to orchids I was growing a variety of succulents, carnivorous plants, and ant plants. Watering the plants was taking about two hours, twice a week, because I didn’t want to spill water on the carpet.

Winter 2001. Metal rack with fluorescent shop lights.  Orchids under lights and succulents overwintering on top.

Winter 2001. Wooden rack with fluorescent shoplights. “Eggcrate” lighting diffuser on plastic sweater boxes for drainage.  Epiphytic myrmecophytes on top shelf, Nepenthes pitcher plants on bottom shelf.

At this point in the standard progression, the orchid addict hobbyist generally looks for an alternative growing area where water can be splashed around without ruining the floor.  In the north, people sometimes convert a basement–preferably one with a floor drain–and grow orchids under lights.  In the south, greenhouses are more common.  Around this time, my wife and I had bought our first house, and like many in North Carolina it was built on a crawl space, not a basement.  Splashing water on the carpet of a rented townhouse only risked our security deposit.  Splashing water on the hardwood floor of our own house was another matter entirely.  I decided to build a greenhouse.

2. The first greenhouse

After obsessive research, I decided to build a 10′ x 16′ frame of pressure-treated lumber and glaze it with 8-mm twin-wall polycarbonate panels.  Although translucent polycarbonate isn’t as attractive as glass, the two layers separated by 8 mm of dead air provide better insulation.  Inexpensive polyethylene film was contraindicated, because the NC piedmont is basically one large forest infested with squirrels.  Trees drop branches, and squirrels drop hickory nuts, both of which can crack glass or tear poly film when they fall from a great height.  I chose pressure treated lumber for the frame, because a) metal was more difficult to work with, b) naturally rot-resistant wood like cedar or redwood was prohibitively expensive, and c) prefabricated greenhouse kits were expensive and often seemed flimsy.

Because the ground doesn’t freeze to any appreciable depth in the NC piedmont, the greenhouse didn’t require a deep insulated foundation.  I rented a two-person auger, and some friends helped to dig six post holes.

Four posts set in concrete form the corners of the greenhouse.  Two more are placed at the middle of the long walls.

The greenhouse was built on a slope, and instead of breaking my back leveling the ground, I built a low wall of 4″x4″ timbers and a single step spanning the full width of the greenhouse half way along its length.  The same friends then helped me build the frame with joists and rafters spaced to support 4′-wide polycarbonate panels. We also framed spaces for an exhaust fan above the door and motorized shutters at ground level on the opposite end.  North Carolina summers are far too hot for the passive roof vents that are used in cooler climates.

Completed greenhouse frame

The polycarbonate panels were attached with stainless steel screws (that wouldn’t corrode in pressure-treated wood). A storm door and an aluminum ridge cap completed the skin of the greenhouse.

Completed greenhouse.  Note the exhaust fan over the door.  Louvers block the exhaust port when the fan is off.

My father-in-law, a plumber, ran a cold water pipe from the house in a trench buried below the frostline, and we used the same trench to run wiring for the lights, exhaust fan, and intake shutters.

Intake shutter in the end of the greenhouse opposite the exhaust fan.  Wiring in conduit runs from the thermostat to the shutter motor.

The greenhouse was cooled by a combination of air exchange and evaporation.  A single-stage thermostat controlled both the exhaust fan and intake shutters.  As the drier outside air entered the greenhouse, a humidistat triggered misting nozzles mounted under benches.  As the mist evaporated, it both cooled and humidified the incoming air.  Using this system, I was able to keep the greenhouse several degrees cooler than the outside air, even on sunny summer days.

For heating, I used a vented Southern Burner greenhouse heater.  The Southern Burner is a very simple design that relies on a pilot light and millivolt thermostat.  The trickle of electricity required to trigger the gas valve is supplied by a thermocouple protruding into the pilot flame, so the heater is completely independent of mains electricity.  This feature proved its worth when we lost electricity for a week following an ice storm.

The Southern burner has an open combustion chamber and requires fresh air.  The PVC pipe behind the heater passively draws in fresh (cold) air from outside as air from inside the greenhouse escapes up the flue.  The wall behind the heater has been insulated with bubble wrap.

The first winter, I learned a couple of things:  1) LP gas (propane) is expensive; 2) although better than glass, twin-wall polycarbonate isn’t a very good insulator, and 3) the north wall of a greenhouse is a heat sink.  I had oriented the greenhouse with its long axis running east-west to take full advantage of the low winter sun, but that orientation meant that the north wall and north slope of the roof received very little light in winter.  To save heating fuel, I wanted to add additional insulation, but insulating a greenhouse is problematic–most substances that are effective insulators are more-or-less opaque.  On the north wall, that wasn’t a problem, so I added Reflectix insulation (basically bubble wrap sandwiched between two layers of reflective film).  On the remaining three walls and north slope of the roof, I used clear bubble wrap to create an additional dead air space without significantly reducing light penetration. Only the south roof was left uncovered to allow maximum penetration of the winter sun.

North wall insulated with reflectix.  The seams between strips of reflectix are sealed with aluminum tape.

This greenhouse served me well for about five years, but when our growing family necessitated a move to a slightly larger house, I seized the opportunity to design a new structure that incorporated some of the lessons I had learned.

3.  The second greenhouse

The second greenhouse–my current greenhouse–was built in 2007. It is 14’x20′ and like the first is polycarbonate on a wooden frame.  I made the new greenhouse wider than the first, because I had learned that 10′ was an awkward width.  When I added two benches for plants along the sides of my first greenhouse, the central aisle was wider than necessary but too narrow to fit a third bench.  14′ is wide enough for three benches and two narrow aisles–more room for plants and less wasted space.

I also considered the problem of the north wall and northern roof slope.  Eventually I settled on an asymmetric roof with a long south-facing slope and short north-facing slope.  Due to the uneven stresses on the walls, this design required the roof to be supported with posts at the ends and at the center of the span.  The post above the door rests on a heavy lintel, and the weight is then distributed to the door frame.

I had initially planned to pour a proper concrete foundation, but the only place suitable for a greenhouse on the new property was directly in front of a beautiful hickory tree.  To protect its roots, I ended up replicating the foundation design of the old greenhouse:  six posts embedded in concrete and connected by 4″x6″ timbers anchored to the ground with rebar.

Greenhouse frame.  The hickory tree that I wanted to save is behind the frame.  The small oak in front was damaged during construction of our home and did not survive.

For glazing, I again used 8-mm twinwall polycarbonate, but this time, the north wall, part of the east and west walls, and the south wall up to the level of the greenhouse benches were all covered with wooden siding.  Behind the siding, I inserted rigid foam insulation and then covered it with Reflectix.  The result was a very bright but well insulated greenhouse.

Completed greenhouse before painting.  The heater vent can be seen to the right of the door, and the propane tank is tucked behind the greenhouse.

I was somewhat dissatisfied with the cooling scheme in my old greenhouse–the misting nozzles left the floor very wet and humidity too high–so I tried a different approach.  Instead of pulling hot air out of the greenhouse with an exhaust fan, I purchased a swamp cooler that pushes cool, humidified air into the greenhouse without making everything too wet.  The particular model I chose is a freestanding, ductless unit that is basically maintenance free, requiring only replacement of the aspen wet pads every few years. Swamp coolers are most efficient in dry climates like the desert southwest, but in humid North Carolina, evaporative cooling keeps the greenhouse under 90 F (32 C) even when the temperature outside spikes above 100 F (38 C).

Pushing cool air into the greenhouse requires that hot air has a way to escape.  The support post above the door meant that I couldn’t tuck an exhaust shutter up under the eaves, so I installed them on the north wall.  The swamp cooler and shutters are controlled by a two stage thermostat allowing them to operate at different temperatures.  The shutters open several degrees below the temperature at which the swamp cooler turns on, so on sunny winter days the greenhouse can be cooled by passive air flow rather than actively blowing large volumes of cold air over the plants.

For heating, I chose an Empire Direct-Vent heater.  Like the Southern Burner, the Empire is controlled by a millivolt thermostat and is completely independent of mains electricity.  However, the combustion chamber of the Empire draws air from outside, allowing the greenhouse to be sealed up tight in cold weather.  There’s no need for cold outside air to be piped into the greenhouse, and warm, humidified air is not lost up a flue.

The final critical piece of equipment is a standby generator so that the cooling system will continue to operate is the electricity goes out during a summer storm.  This generator also runs our refrigerator, freezer, and well pump (allowing toilets to be flushed), so it was an easy sell to the non-orchid-growing members of the family.

Greenhouse interior, looking west.  The empire heater is seen at left.  Exhaust shutters in the north wall are open to cool the greenhouse.  The Reflectix box mounted on the central post houses the thermostat for the cooling system.  This photo was taken in winter, so the door is hidden behind a polyethylene sheet that blocks any draughts.

Greenhouse interior, looking east.  The swamp cooler is located at ground level, hidden just below the orange vireya flowers, so air enters the corner of the greenhouse opposite the exhaust vents.  The benches are made of wire closet shelves resting on concrete blocks.

This greenhouse has now been in operation for almost 12 years, long enough for me to thoroughly assess its strengths and weaknesses.  The evaporative cooler works very well, as does the direct-vent heater.  The greenhouse is much better insulated than my previous design, and the long south-facing slope of the roof, combined with reflective covering of the high north wall makes it much brighter.    The greenhouse is over 12′ (almost 4 m) tall, a somewhat ridiculous height, but the steep pitch of the roof sheds snow very nicely.  However, the 12′ 6″ south slope of the roof is really too long for a single polycarbonate panel.  At that length expansion and contraction at different temperatures is significant enough to loosen screws, and there is no easy way to access the center of the roof to tighten them.  Because the exhaust shutters are in the north wall, hot air becomes trapped in the peak of the roof and may shorten the lifespan of the polycarbonate panels.

A longer and narrower design would have reduced the height of greenhouse and made the roof panels shorter, perhaps reducing the problem of expansion and contraction.  Vents mounted in the north slope of the roof would have prevented hot air from becoming trapped, but designing a hood to keep off rain would have been complicated.  Overall, however, I am pleased with the performance of my greenhouse design. It allows me to grow a very wide range of plants, as you can see from the various entries on this blog.

Mushroom log garden (Six on Saturday #38, November 24, 2018)

After the remnants of Hurricane Michael knocked down a couple of our neighbors’ trees (see picture #6), they generously offered us some of the wood.  It’s not every day that I have access to such big, beautiful oak logs, so I decided to use them for something more fun than firewood.

1. The wood


2. The mushrooms

Wooden plugs colonized by lion’s mane or shiitake mycelium.  The ‘Wide Range” shiitake fruits at 55-75 F (13-24 C) , while “N.C. Wild” fruits at 85-105 F (30-41 C).  The combination should offer the possibility of mushrooms during much of spring, summer, and autumn.

3.  The guide book

This book is focused mainly on indoor growing, but it has a useful section on log cultivation.

4. The location

The kids don’t use their old sandbox any more.  It is well shaded, and I thought the walls and sandy bottom would help to create a sheltered, humid microclimate.  I covered the ground with corrugated cardboard, so that heavy rain wouldn’t kick up sand and make the mushrooms gritty.

5. The procedure

Drill holes.

Insert plugs and pound them in with a rubber mallet.

Seal the holes with melted cheese wax.

6. The log garden

The finished log garden under a good soaking rain.  Now I wait.

For more Six on Saturday, head on over to The Propagator.  After viewing his Six, check out the comments for links from other participants.